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Effects of the Eastern Carpathians on atmospheric circulations and precipitation chemistry from 2006 to 2016 at four monitoring stations (Eastern Carpathians, Romania)
Abstract
A comprehensive study on the chemical composition of rainwater was carried out from 2006 to 2016 in four sampling locations from the Eastern Carpathians, Romania, in order to study the differences between the precipitation chemistry and atmospheric circulations of intra-mountain and extra-mountain areas. All samples were analyzed for pH, electrical conductivity and major ions. Daily precipitation data recorded during 1981–2016 was used to disseminate weather types that lead to the occurrence of high precipitation days. ERA reanalysis (Interim version) was used to build a database for the atmospheric circulation types, using multiple methods to compare if similar synoptic patterns are specific for the days with >10 mm of rain. Correlation between precipitation and elevation showed the orographic convection and the barrier effect. The average pH was 6.6 at Ciuc basin (CB), 6.8 at Giurgeu basin (GB), 6.9 at Deda-Toplița Pass (DTP) and 6.6 at Odorheiu sub mountain basin (OSB). Lowest pH values were measured at OSB. Here, 12% of the samples were observed to be acidic, compared to 3.31% at CB, 0.80% at GB and 1.70% at DTP. NH4⁺ was the most abundant ionic species at CB, GB and DTP; at OSB the dominance of both Ca²⁺ and NH4⁺ was observed. SO4²⁻ was the most predominant anion at all sampling sites, having the highest volume weighted mean (159 μeql⁻¹) concentration at OSB. Neutralization factors, ionic ratios and the ammonium neutralization index showed the neutralization potential of NH4⁺ and Ca²⁺ over acidic components. Spearman correlation and Principal Component Analysis showed the sources of major ions. Significant correlation between Na⁺ and Mg²⁺ (R = 0.63) at OSB suggests the same source (marine) origin, from the long range transported sea sprays, and the lack of correlation between these cations at CB, GB and DTP confirms the blocking effect of the Carpathians Mountain chain.
... The average amount of precipitation from 2016 to 2019 was 726 ± 74 mm ( Fig. 2c), with most of the rain events (76%) occurring in summer and autumn (June-November, defined as a wet season) and the remaining portion (24%) occurring in winter and spring (December-May, defined as a dry season), which was similar to a previously reported seasonal distribution of urban precipitation in Xi'an (Zhou et al., 2012). The pH values varied from 4.7 to 8.1, with a VWM of 6.8 (Table 1), and approximately 97% of the values above 5.6 (the signal to identify acid rain events) (Charlson & Rodhe, 1982) ( Fig. S2a) were associated with the significant impact of alkaline materials (e.g., dust and NH 3 ) in the atmosphere as well as the neutralization of acidity by the abundant alkaline substances (calcium and magnesium) in the soil of northern China (Robert et al., 2018;Xu et al., 2009). In addition, anthropogenic factors were considered stringent emission controls for acid gas (SO 2 and NO x ) and relatively stable NH 3 emissions from agricultural activities in recent years (Zheng et al., 2018). ...
... Anthropogenic sources including chemical fuel combustion and vehicle emissions are major contributors of airborne NO x and SO x , the precursors of NO 3 − and SO 4 2− Masood et al., 2018;Pant et al., 2015;Singh et al., 2017;Tiwari et al., 2015). The possible sources of fuel combustion are from coal-fired power plants, high-temperature operations in industry, oil refineries, copper smelters and brick kilns (Agnes et al., 2020;Bhuyan et al., 2020;Do et al., 2021;Mimura et al., 2016;Robert et al., 2018). It is noteworthy that the use of home heaters and gas stoves could also generate large amount of oxides of sulfur and nitrogen, which will accumulate high levels of water-soluble sulfates and nitrates through a series of photochemical reactions (Agnes et al., 2020;Zeng et al., 2020). ...
... The high proportion of NH 4 + was closely correlated with the large amount of NH 3 and particulate ammonium dissolved in rainwater. Xi'an is located in a well-developed agricultural region (Guanzhong Plain); thus, nearby rural NH 3 -rich areas could transport long-distance NH 3 (Meng et al., 2019;Robert et al., 2018). ...
Atmospheric wet deposition (AWD) is closely related to air quality, and excessive deposition poses risks to ecological systems and human health. Seasonal and interannual variations in acidity, electric conductivity (EC), ionic composition, fluxes, sources, and atmospheric transport of AWD were analyzed at an urban site in Xi’an from 2016 to 2019. The annual volume-weighted mean (VWM) pH and EC values were 6.8 and 40.6 μS cm−1, respectively. NO3− (47%) was the most dominant anion, while Ca2+ (34%) was the most dominant cation. The analysis of fractional acidity (FA) and neutralization factors (NFs) showed that 96% of the acidity was neutralized by alkaline constituents, especially Ca2+ and NH4+. The annual AWD flux of total ions was 125.9 kg ha−1 year−1, and NO3−, NO2−, SO42− and NH4+ fluxes accounted for approximately 70%, indicating considerable sulfur (9.1 kg ha−1 year−1) and nitrogen (22.0 kg ha−1 year−1) deposition. Under dilution by precipitation, the EC and major ion concentrations were lower, while the pH and fluxes were higher, in summer and autumn, and the opposite results were observed in spring and winter. The source apportionment via by positive matrix factorization (PMF) revealed that the six sources of major ions were confirmed as follows: vehicular emissions (38.1%), agriculture (22.3%), fossil fuel combustion (13.8%), crust (12.9%), marine (9.6%), and biomass burning (3.3%). And on the basis of back trajectory analysis, the air masses of precipitation were primarily from the northwest in spring and winter, from the southeast in summer, and from various directions in autumn, and they transported different natural and anthropogenic pollutants along their paths, thereby affecting the chemical composition and fluxes of AWD.
... The origin of Nr and other ionic species was accessed by calculating enrichment factor and statistically inferential methods such as Pearson correlation coefficient analysis and Principal component analysis (Akpo et al. 2015;Szép et al. 2018;Han et al. 2019). ...
... 6) and equation 7 (Eq. 7), respectively, frequently cited in previous studies (Kulshrestha et al. 1996;Szép et al. 2018). ...
... These EF sea and EF soil values clearly showing the dominant crustal contribution of K + and Mg 2+ across all three sites. Further, these EF sea and EF soil are in accord with many previously conducted studies Szép et al. 2018). The EF sea value for Ca 2+ ranged from 176.2 at LNI site to 357.2 at BRT, while the EF soil values of this ion were observed to be unity across all sites (Table 4). ...
The present study comprehensively reports the simultaneous measurement of wet deposition of total inorganic nitrogen (TIN; which is the sum of the NH4⁺-N and NO3⁻-N) at three different sites in Nr emission hotspot of Indo-Gangetic plain (IGP) over a year-long temporal scale from October 2017 to September 2018. At rural Meetli (MTL) site, urban Baraut (BRT) site and industrial Loni (LNI) site, the annual wet deposition of NH4⁺-N was estimated as 21.87, 19.48 and 7.43 kg N ha⁻¹ yr⁻¹, respectively; the annual wet deposition NO3⁻-N was estimated as 12.96, 12.17 and 4.44 kg N ha⁻¹ yr⁻¹, respectively; and the annual wet deposition of TIN was estimated as 34.83, 31.64 and 11.87 kg N ha⁻¹ yr⁻¹, respectively. NH4⁺-N was dominantly contributing species in annual, monsoon and non-monsoon-time wet deposition of TIN at all sites. The spatial gradient (variability) in percent contribution of NH4⁺ to total annual volume-weighted mean (VWM) concentration of all analyte ions was observed as MTL (43.23%) > BRT (37.90%) > LNI (30%). On the other hand, the spatial gradient in percent contribution of NO3⁻ to total annual VWM concentration of all analyte ions was observed as MTL (7.45%) > BRT (6.89%) > LNI (5.32%). The extremely narrow range of NH4⁺-N/NO3⁻-N ratios (ranging from 1.60 at BRT site to 1.69 at LNI site) showed the approximately equal relative abundance of oxidized and reduced nitrogen (N) deposition across all sites. Inferences from enrichment factor analysis, principal component analysis and Pearson’s correlation coefficient analysis suggested that across all sites, virtually all NH4⁺-N and NO3⁻-N depositions were originated anthropogenically. The annual wet deposition of TIN measured in this study showed ≥ 6865%, ≥ 6228% and ≥ 2274% increment than the natural N deposition rate at MTL, BRT and LNI site, respectively. These empirically measured annual wet depositions of TIN also emanated theoretical transgression of critical N load threshold across all sites therefore signifying probable undermining of long-term elastic stability and resilience of ecosystems against stressor in the study domain.
... The previous work has categorized three types of major ions (chemical species) origins in rainwater, including curst sources (terrestrial dust), marine sources (sea-salt input), and anthropogenic sources (human emission) (Jain, Madhavan & Ratnam, 2019;Liu et al., 2013;Xu et al., 2015). All of the source variations, local meteorology, geomorphology, and environmental protect guidelines affect the rainwater chemical species (Cable & Deng, 2018;Szép et al., 2018). ...
... Overall, the ions concentrations presented a converse temporal trend to the precipitation amount from the monthly scale (Fig. 3). This revealed that precipitation amount is the important factor impacting rainwater ionic species, which is in agreement to the previous findings (Keresztesi et al., 2020b; Szép et al., 2018). The more clear relationship between rainfall amount and ions concentrations were illuminated in Figs. ...
... 4I-4P) revealed that ions concentrations in Guiyang city are observably impacted by the dilution effect (or scouring effect) under large rainfall amount (e.g., r = −0.84 for Ca 2+ and r = −0.77 for SO 2− 4 , p < 0.05), which is commonly found in other areas (Silva, Gonçalves & Freitas, 2009;Szép et al., 2018). In this scouring process, the air components, such as sulfur/nitrogen oxides, Mg and Ca-mineral, and particulate nitrate (e.g., nitrated phenols (Li et al., 2020b)) are powerfully scoured down (below-cloud processes) during the early rain-stage, causing the high ionic concentration observed under the low precipitation amount condition (Jia & Chen, 2010). ...
The rainwater chemistry and related air contaminants are used to investigate the rainwater ions sources, variations, and influence factors from 2012 to 2014 in Guiyang city (the typical karst urban area of Southwest China). According to temporal rainwater ion concentrations, the obvious variations were presented in the study period, such as Ca2+ (125~6652 μeq L-1) and SO42- (11~4127 μeq L-1). Consequently, Ca2+, Mg2+, SO42-, and Cl- are considered as the leading ions. Three critical influencing factors of rainwater ions concentrations, including sources variations, rainfall amount, and long-distance migration (rainfall amount >100mm) are identified. Based on the typical ionic ratios, source identification suggested that anthropogenic inputs mainly contributed to F-, NO3-, and SO42-, while the dusts (crustal sources) are the primary sources of Mg2+, Ca2+, and K+. Cl- Enrichment in long-distance transport is the main contributor of Cl-. According to the observation of high level of total wet acid deposition, the more detailed spatio-temporal monitoring of rainfall-related acid deposition (particularly sulfur deposition) is required to understand its potential environmental effects in the aquatic ecosystem of the earth surface.
... K + mass concentrations were rela-tively low during this period, while elevated C 2 O 2− 4 concentrations at this time were independent of K + (Fig. 4). Both K + and C 2 O 2− 4 have known biomass burning sources and have been used as tracers for biomass burning (e.g., Park et al., 2013;Park and Yu, 2016;Szép et al., 2018;Johansen, et al., 2019). However, they also have other sources that can complicate their usage for such a purpose. ...
... However, they also have other sources that can complicate their usage for such a purpose. For example, C 2 O 2− 4 can be formed by aqueous-phase cloud chemical processes (e.g., Huang et al., 2006;Ervens et al., 2011), and fine-fraction K + can arise from fertilizer use (e.g., Szép et al., 2018;Han et al., 2019), fireworks (Hao et al., 2018;ten Brink, et al., 2019), and anthropogenic combustion sources (Jayarathne et al. 2018;Han et al., 2019;Yan et al., 2020) such as coal, garbage incineration, and cooking fuels, with charcoal in particular exhibiting enhanced K + (Jayarathne et al. 2018). Levoglucosan has also been used as a biomass burning tracer; however, its relative contribution has been shown to decrease with smoke plume age (Cubision et al., 2011), and recent work indicates that it is short-lived in the atmosphere such that it is useful for fresh emissions but not for aged biomass burning aerosol (Wong et al., 2019). ...
... However, they also have other sources that can complicate their usage for such a purpose. For example, C 2 O 2− 4 can be formed by aqueous-phase cloud chemical processes (e.g., Huang et al., 2006;Ervens et al., 2011), and fine-fraction K + can arise from fertilizer use (e.g., Szép et al., 2018;Han et al., 2019), fireworks (Hao et al., 2018;ten Brink, et al., 2019), and anthropogenic combustion sources (Jayarathne et al. 2018;Han et al., 2019;Yan et al., 2020) such as coal, garbage incineration, and cooking fuels, with charcoal in particular exhibiting enhanced K + (Jayarathne et al. 2018). Levoglucosan has also been used as a biomass burning tracer; however, its relative contribution has been shown to decrease with smoke plume age (Cubision et al., 2011), and recent work indicates that it is short-lived in the atmosphere such that it is useful for fresh emissions but not for aged biomass burning aerosol (Wong et al., 2019). ...
This two-part study explores hyperspectral (300–700 nm) aerosol optical measurements obtained from in situ sampling methods employed during the May–June 2016 Korea–United States Ocean Color (KORUS-OC) cruise conducted in concert with the broader air quality campaign (KORUS-AQ). Part 1 focused on the hyperspectral measurement of extinction coefficients (σext) using the recently developed in situ Spectral Aerosol Extinction (SpEx) instrument and showed that second-order polynomials provided a better fit to the measured spectra than power law fits. Two dimensional mapping of the second-order polynomial coefficients (a1, a2) was used to explore the information content of the spectra. Part 2 expands on that work by applying a similar analytical approach to filter-based measurements of aerosol hyperspectral total absorption (σabs) and soluble absorption from filters extracted with either deionized water (σDI-abs) or methanol (σMeOH-abs). As was found for σext, second-order polynomials provided a better fit to all three absorption spectra sets. Averaging the measured σext from Part 1 over the filter sampling intervals in this work, hyperspectral single-scattering albedo (ω) was calculated. Water-soluble aerosol composition from the DI extracts was used to examine relationships with the various measured optical properties. In particular, both σDI-abs(365 nm) and σMeOH-abs(365 nm) were found to be best correlated with oxalate (C2O42-), but elevated soluble absorption was found from two chemically and optically distinct populations of aerosols. The more photochemically aged aerosols of those two groups exhibited partial spectra (i.e., the longer wavelengths of the spectral range were below detection) while the less-aged aerosol of the other group exhibited complete spectra across the wavelength range. The chromophores of these groups may have derived from different sources and/or atmospheric processes, such that photochemical age may have been only one factor contributing to the differences in the observed spectra. The differences in the spectral properties of these groups was evident in (a1, a2) maps. The results of the two-dimensional mapping shown in Parts 1 and 2 suggest that this spectral characterization may offer new methods to relate in situ aerosol optical properties to their chemical and microphysical characteristics. However, a key finding of this work is that mathematical functions (whether power laws or second-order polynomials) extrapolated from a few wavelengths or a subrange of wavelengths fail to reproduce the measured spectra over the full 300–700 nm wavelength range. Further, the σabs and ω spectra exhibited distinctive spectral features across the UV and visible wavelength range that simple functions and extrapolations cannot reproduce. These results show that in situ hyperspectral measurements provide valuable new data that can be probed for additional information relating in situ aerosol optical properties to the underlying physicochemical properties of ambient aerosols. It is anticipated that future studies examining in situ aerosol hyperspectral properties will not only improve our ability to use optical data to characterize aerosol physicochemical properties, but that such in situ tools will be needed to validate hyperspectral remote sensors planned for space-based observing platforms.
... Rainwater is the most important sink of air pollutants, such as acid gases and particulate matter (PM) [1][2][3][4]. In-cloud and below-cloud scavenging processes are the keys to the removal of air contaminants during a whole rainfall event [5,6], and the rainwater pH and chemical species are changed concomitantly [7][8][9]. Moreover, investigating rainwater chemical composition is helpful for understanding air quality, which can be used to explore the origins of air contaminants based on the different physical and chemical processes of these contaminants [10][11][12]. ...
... Typically, previous studies have classified the sources of rainwater chemical components (major ions) into three types: sea-salt input (marine sources), terrestrial dust (crustal sources), and human-made emissions (anthropogenic sources) [13][14][15]. In addition to source variations, factors affecting the chemical composition of rainwater include geomorphic situations, meteorological conditions, and environmental policies [4,16,17]. ...
... Therefore, the VWM values were more appropriate for comparison [14]. Accordingly, the major ion concentrations in the MNKFP followed the order of SO 4 ...
Temporal rainwater chemistry was used to reveal air pollution in the Maolan National Karst Forest Park (MNKFP), which is representative of the typical karst forest region of southwest China (SW China). The rainwater ions’ sources, variations, trends, and potential environmental effects were investigated from 2007 to 2010 and from 2013 to 2014. Based on the analysis of the temporal ionic concentrations of rainwater in the MNKFP, significant variations of ions were observed, including in NH4+ (9.7~266.6 μeq L−1) and SO42− (14.5~1396.4 μeq L−1), which were mainly controlled by variations in the source and rainfall amount; a decreased trend of rainwater pH was also observed. Accordingly, NH4+, Ca2+, SO42−, and Cl− were regarded as the most dominant ions. Typical ionic ratios and positive matrix factorization (PMF) model-based source apportionment suggested that anthropogenic inputs (coal combustion, industrial, traffic, and agricultural emissions) contributed 51% of F−, 93% of NO3−, 62% of SO42−, and 87% of NH4+, while the natural sources (crustal dust and sea salt) were the main sources of Cl− (74%), Na+ (82%), K+ (79%), Mg2+ (94%), and Ca2+ (93%). In combination with the reducing neutralization trend of temporal rainwater observed in the MNKFP and the potential effect of rainwater ion deposition on karst forests, more detailed monitoring of the rainfall-related deposition process is required for a better understanding of its potential environmental effects on the Earth’s surface.
... Table 2 presents the ratio of EFm to EFc. If the EF value is significantly larger or smaller than 1, the element's corresponding reference source was enriched or diluted, respectively [18,37,38]. ...
... Table 2 presents the ratio of EF m to EF c . If the EF value is significantly larger or smaller than 1, the element's corresponding reference source was enriched or diluted, respectively [18,37,38]. (6) and (7), Na + is used as a sea source reference, Ca 2+ is used as crust source reference [3,14]. ...
... The source may have been crustal, with a part from other sources. The EF m of Ca 2+ (6.06 for Wanli and 19.73 for Banqiao) indicated that it did not come from marine sources and may have been derived from the soil, land dust or limestone, or the weathering of dolomite [38]. The EF m (3.96 for Wanli and 12.3 for Banqiao) and EF c (94.6 for Wanli and 89.9 for Banqiao) of SO 4 2− existed in a highly enriched form. ...
In this study, temporal variations, major ion reference indexes, correlation analysis, and statistical data were used to investigate the chemical characteristics of the atmospheric pollutants in wet deposition and reasons for their formation, and further insight into the impact of local and regional atmospheric pollutant distributions on urban and coastal area environments. From November 2014 to October 2015, 158 rainwater samples were collected in coastal Wanli and urban Banqiao of southern Northeast Asia (northern Taiwan). The mean pH of the coastal and urban was 4.63 and 4.58, respectively, lower than the mean (5.31) of 10 East Asia regions during the year of 2015. This was possibly because the concentration of the combined SO42− and NO3− in the study area were greater than the mean of the 10 East Asian regions. This is verified by the calculation of sea-salt fraction (SSF) and non-SSF fraction (NSSF) in study areas, which indicated that Na+ and Cl− accounted for over 85% of the SSF, without Na+ in Banqiao, were mainly due to marine sources. For the NSSF, in addition to SO42− in Wanli, nearly 90% of wet disposition was from SO42− and NO3−, which were emitted from human activities. Furthermore, the analysis of fractional acidity (FA), neutralization factors (NF), neutralization potential (NP), and acidification potential (AP) revealed that acidified precipitation was caused by a lack of neutralizing compounds, which resulted in less neutralization of acidic precipitation. Finally, the results of correlation and principal component analysis (PCA) indicated that because coastal area were geographically closer to the ocean, wet deposition mainly comes from marine sources. However, in urban with a high population density and high traffic quantity, the ions in wet deposition primarily come from anthropogenic activities, such as industrial combustion and vehicle emissions.
... The long-term changes of chemical composition of atmospheric precipitation depends on many factors, but the decisive factors are changes in air pollutant emissions as well as changes in meteorological processes affecting their transformation into a liquid phase in clouds and precipitation [30,31]. The resulting changes are thus an integrated indicator of complex physicochemical transformations of pollutants from the emission source to the captured precipitation at a specific location [30,[32][33][34]. ...
... The long-term changes of chemical composition of atmospheric precipitation depends on many factors, but the decisive factors are changes in air pollutant emissions as well as changes in meteorological processes affecting their transformation into a liquid phase in clouds and precipitation [30,31]. The resulting changes are thus an integrated indicator of complex physicochemical transformations of pollutants from the emission source to the captured precipitation at a specific location [30,[32][33][34]. The results of many observations, especially in the northern hemisphere, point to significant changes in precipitation chemistry, especially in pH values, concentrations of sulfur, nitrogen, but also basic cations. ...
... Several studies confirm that the primary cause of the decrease of pollutants in atmospheric precipitation is a decrease in sulfur and nitrogen emissions due to the application of measures under the Convention on Long-Range Transboundary Air Pollution-CLRTAP [1,2,7], although the decrease in emissions does not fully explain all observed pollutant trends [3]. Changes in other factors such as changes in air temperature and precipitation, changes in atmospheric circulation, or the occurrence of extreme weather events must also be taken into account [30,32,33]. ...
The paper is focused on the evaluation of long-term changes in the chemical composition of precipitation in the mountain forests of Slovakia. Two stations with long-term measurements of precipitation quality were selected, namely the station of the EMEP (European Monitoring and Evaluation Programme) network Chopok (2008 m a.s.l.) and the station of the ICP Forests (International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests) network Poľana-Hukavský grúň (850 m a.s.l.). All basic chemical components were analyzed, namely sulfur (S-SO4), nitrogen (N-NH4, N-NO3), and base cations (Ca, Mg, and K) contained in precipitation. The time changes of the individual components were statistically evaluated by the Mann-Kendall test and Kruskal-Wallis test. The results showed significant declining trends for almost all components, which can significantly affect element cycles in mountain forest ecosystems. The evaluated forty one-year period (1987 to 2018) is characterized by significant changes in the precipitation regime in Slovakia and the obtained results indicate possible directions in which the quantity and quality of precipitation in the mountainous areas of Slovakia will develop with ongoing climate change.
... K + mass concentrations were relatively low during this period, while elevated C2O4 2concentrations at this time were independent of K + (Fig. 4). Both K + and C2O4 2have known biomass burning sources and have been used as tracers for biomass burning (e.g., Park et al., 2013;Park and Yu, 2016;Szép et al., 2018;Johansen, et al., 2019). However, they also have other sources that can complicate their usage for such a purpose. ...
... However, they also have other sources that can complicate their usage for such a purpose. For example, C2O4 2can be formed by aqueous-phase cloud chemical processes (e.g., Huang et al., 2006;Ervens et al., 2011) and fine fraction K + can arise from fertilizer use (e.g., Szép et al., 2018; Levoglucosan has also been used as a biomass burning tracer, however, its relative contribution has been shown to decrease with smoke plume age (Cubision et al., 2011) and recent work indicates that it is shortlived in the atmosphere such that it is useful for fresh emissions, but not for aged biomass burning aerosol (Wong et al., 2019). 3 390 shows m/z 60 from the nebulized water-soluble extracts was negligible throughout the campaign. ...
... Han et al., 2019), fireworks(Hao et al., 2018;ten Brink, et al., 2019), and anthropogenic combustion sources(Jayarathne et al. 2018;Han et al., 2019;Yan et al., 2020) such as coal, garbage incineration, and cooking fuels, with charcoal in particular exhibiting enhanced K +(Jayarathne et al. 2018). ...
This two-part study explores hyperspectral (300–700 nm) aerosol optical measurements obtained from in situ sampling methods employed during the May–June 2016 Korea United States – Ocean Color (KORUS-OC) cruise conducted in concert with the broader air quality campaign (KORUS-AQ). Part 1 focused on the hyperspectral measurement of extinction coefficients (σext) using the recently developed in situ Spectral Aerosol Extinction (SpEx) instrument and showed that 2nd order polynomials provided a better fit to the measured spectra than power law fits. Two dimensional mapping of the 2nd order polynomial coefficients (a1,a2) was used to explore the information content of the spectra. Part 2 expands on that work by applying a similar analytical approach to filter-based measurements of aerosol hyperspectral total absorption (σabs) and soluble absorption from filters extracted either with deionized water (σDI-abs) or methanol (σMeOH-abs). As was found for σext, 2nd order polynomials provided a better fit to all three absorption spectra sets. Averaging the measured σext from Part 1 over the filter sampling intervals in this work, hyperspectral single scattering albedo (ω) was calculated. Water-soluble aerosol composition from the DI extracts was used to examine relationships with the various measured optical properties. In particular, both σDI-abs(365 nm) and σMeOH-abs(365 nm) were found to be best correlated with oxalate (C2O42−), but elevated soluble absorption was found from two chemically and optically distinct populations of aerosols. The more photochemically aged aerosols of those two groups exhibited partial spectra (i.e., the longer wavelengths of the spectral range were below detection) while the less-aged aerosol of the other group exhibited complete spectra across the wavelength range. The chromophores of these groups may have derived from different sources and/or atmospheric processes, such that photochemical age may have been only one factor contributing to the differences in the observed spectra. The differences in the spectral properties of these groups was evident in (a1,a2) maps. The results of the two-dimensional mapping shown in Parts 1 and 2 suggest that this spectral characterization may offer new methods to relate in situ aerosol optical properties to their chemical and microphysical characteristics. However, 2nd order polynomials did not fully capture the evident features in the σabs and ω spectra, suggesting additional spectral analyses such as peak fitting will yield additional information. It is anticipated that future studies examining in situ aerosol hyperspectral properties will not only improve our ability to use optical data to characterize aerosol physicochemical properties, but that such in situ tools will be needed to validate hyperspectral remote sensors planned for space-based observing platforms.
... Recent studies on country-wide climatic changes in Romania over the last decades showed an increase in extreme events like heat waves [22][23][24] and drought [25], which also affect the streamflow regime [26], the terrestrial ecosystems [27][28][29][30][31], and human health [32]. Here, the increase in frequency of thermal extremes is of particular interest [33][34][35][36][37]. Several studies highlighted the influence of large-scale circulation patterns and air temperature and precipitation regimes [38][39][40][41]. ...
... We have chosen to analyze the mean air temperature instead of the daily minimum temperature, because the first shows a more stable and persistent atmospheric condition. The analysis was extended to all Romanian weather stations that provided this kind of information during the above mentioned period, resulting in a total number of 127 weather stations, distributed as follows: 40 For all the weather stations, the soil temperature measurements were performed with mercury-in-glass and alcohol thermometers. Regarding the air temperature, this parameter was measured with mercury-in-glass thermometers until the automatic equipment was installed at the weather stations. ...
Daily time series with continuous records of mean air and soil temperature from 127 meteorological stations—fairly distributed over the country—were used to compute monthly temperature trends, as well as changes in the timing of the first and the last frost days over Romania since 1961. Results show that the frequency of the number of days with daily temperature averages below 0 °C in case of air and soil surface temperature is stable for most months, except for January, when (for both soil and air temperature), the number of days with a temperature below 0 °C is decreasing in the majority of the stations. The occurrence of the first day with (mean air and soil surface) temperatures below 0 °C, presents a delay in the south, south-east, and west, and an earlier occurrence in eastern and central regions. The occurrence of the last day with a mean air and soil surface temperature below 0 °C shows a stable trend for most stations (except for some small areas in the north, south-east and south-west of Romania). The regime of the land temperature is more stable, due to the physical characteristics of the soil, compared to the more versatile atmosphere. Linkages between thermal parameters and large-scale atmospheric circulation are also discussed.
... Bulk precipitation chemistry data suggest at least one NSS Ca 2+ source. Calcium in precipitation is often attributed to crustal dust transport (Brahney et al., 2013;Loye-Pilot et al., 1986;Niu et al., 2014;Szép et al., 2018;Xiao, 2016;Zhang et al., 2003). Longrange transport is possible; however, a more spatially uniform distribution of NSS Ca 2+ would be expected across all precipitation collectors, as was observed with NSS Na + . ...
... Rock and aeolian transport weathering can disperse substantial quantities of these constituents over vast distances (Chung & Park, 1998). Many studies have linked the presence of Ca 2+ and Mg 2+ in precipitation to terrestrial dust transport (Niu et al., 2014;Szép, 2019;Szép et al., 2018;Xiao, 2016;Zhang et al., 2003;Loye-Pilot et al., 1986;Brahney et al., 2013). Biomass burning and potash fertilization have also been linked to elevated K + in bulk precipitation (Keresztesi et al., 2020;Lu et al., 2011). ...
Precipitation is the primary groundwater source for the Island of Oʻahu, Hawaiʻi, USA, and is an important source of terrestrial nutrients. Since Pacific Islands are particularly vulnerable to the impacts of climate change, they are important venues for studying the controls on and fluctuations in precipitation chemistry. Spatial variations in some of the dissolved rainfall ions can also be of value as natural geochemical tracers in examining surface and groundwater flow. This study collected and chemically analyzed bulk precipitation from 20 sites across the Island of Oʻahu approximately quarterly between April 2018 and August 2021. The new precipitation chemistry data were integrated with previously published precipitation data to characterize major ion composition and examine the atmospheric processes controlling inorganic ion deposition. Linear regression and multivariate analysis were used to quantify the relationships among major ions and to assess the impacts of various environmental and meteorological factors on precipitation chemistry. Ordinary kriging and inverse distance weighted interpolations were conducted to help visualize spatial variations in major ion deposition. The results clearly indicate that ocean sea spray is the primary driver of precipitation inorganic chemistry, with marine sea salt aerosols accounting for more than 90% of the measured ion load. However, they also show that various weather patterns and nutrient sources impact inorganic deposition. Most notably, upper atmospheric transport of Asian continental dust during Hawaiian wet seasons, Ca2+ from local sedimentary deposits, and anthropogenic K+ from agricultural activity appear to be substantial non-marine deposition sources. This study synthesizes data from multiple sources into the most spatially and topographically diverse precipitation collector network on Oʻahu to date. The findings from this effort help establish a baseline for assessing future fluctuations in inorganic ion deposition and lay important groundwork for examining connections between precipitation and groundwater chemistry within the study area.
... These changes in climatic parameters were proved to significantly impact the natural river flow regime [31], forest development [32][33][34] or human health [35,36]. Recent comprehensive studies report changes in precipitation chemistry, both in the region of study [37][38][39][40][41], as well as at continental scale [32][33][34][35][36][37][38] ...
... These changes in climatic parameters were proved to significantly impact the natural river flow regime [31], forest development [32][33][34] or human health [35,36]. Recent comprehensive studies report changes in precipitation chemistry, both in the region of study [37][38][39][40][41], as well as at continental scale [32][33][34][35][36][37][38] ...
Long-term variations of ozone and its precursors have been examined in an intra-mountain closed basin during January 1st 2008 and June 30th 2017. A complete assessment of surface ozone concentration is given, investigating the ozone cycle, the weekend effect, seasonal and diurnal variability of O 3 and its precursors, photolysis of O 3 and the atmospheric oxidation. The highest hourly concentration of O3 in the studied period was 163.33 µg/m3. Regarding seasonal O 3 multiannual concentrations, the highest values were measured during spring and summer. The daily hourly concentrations of O 3 in the weekends were higher by 3.55% than those on weekdays, as well as O 3 accumulation rates, yielding 2.19 µg/m3h and 2.11 µg/m3h on weekends and weekdays, respectively. In the Ciuc basin, the NOx-independent contributions value is 42.33 µg/m3, which is equivalent to background O 3 concentrations. O3 variations are studied through a case study during 2008-2017, taking under consideration one atmospheric stable period, studying the Brunt-Väisälä frequency, the total column of O 3 and the boundary layer height.
... The NH 4 + concentration is similar to the rainwater collected from the Bay of Bengal (Figure 6). Such high-level NH 4 + is beyond the requirement of neutralization (NH 4 + to neutralize nss-SO 4 2− and NO 3 − ; Supplementary Figure S5) when ammonium available index (AAI) is introduced (Szép et al., 2018). Large AAI indicates the excessive NH 4 + from intensive human activities (Szép et al., 2018). ...
... Such high-level NH 4 + is beyond the requirement of neutralization (NH 4 + to neutralize nss-SO 4 2− and NO 3 − ; Supplementary Figure S5) when ammonium available index (AAI) is introduced (Szép et al., 2018). Large AAI indicates the excessive NH 4 + from intensive human activities (Szép et al., 2018). Concurrently, nss-ions, e.g., Ca 2+ and K + , also markedly increased, suggesting the input from terrestrial materials into the rainwaters (Martino et al., 2013). ...
Atmospheric deposition is the dominant pathway for the loading of exogenous nitrogen (N) to open ocean. Here, rainwater samples were collected from 31 stations in the equatorial East Indian Ocean (EIO) and West Pacific Ocean (WPO) to explore the spatial variability of N species, potential sources, and related ecological influences. Among two oceans, nitrate (NO3–) and ammonium (NH4⁺) were the main components in the rainwater N inventory. NO3– concentrations varied from 0.19 to 100.5 μM, whereas NH4⁺ concentrations ranged from 0.54 to 110.6 μM. Among all stations, low concentrations of NO3– and NH4⁺ appeared in the remote ocean, whereas high concentrations were observed at the stations near the Malacca Strait and New Guinea, coupled with an enhancement of non-sea salt major ions, e.g., calcium ions (Ca²⁺) and sulfate (SO42–), revealing the influence from coastal human activities, such as coal and gasoline combustion. In the remote ocean, δ¹⁵N–NH4⁺ ranged from −5.7 to −9.3‰, whereas it dropped to -15.5‰ near coasts. A logarithmic decay between δ¹⁵N–NH4⁺ and NH4⁺ concentrations in rainwater samples was obtained, suggesting a shift from natural source (seawater emission) in oceanic precipitation events to anthropogenic source (chemical fertilizer volatilization and vehicle exhaust) in coastal rainwaters. δ¹⁵N–NO3– in the remote ocean varied between −1.7 and 0.4‰ with low levels found in the WPO, likely related to the ascending air flow driven by the Walker Circulation. In coastal oceans, δ¹⁵N–NO3– ranged from 1.5 to 3.5‰. The linkage between δ¹⁵N–NO3– and NO3– concentrations varied in two oceans, resulting from difference in biological and fossil fuel combustion contributions. Compared with ocean surface water, N in the rainwater was markedly enriched, suggesting that N from atmospheric wet depositions could rapidly enhance the dissolved N availability in ocean surface water. However, the N redundancy according to the Redfield–Brzezinski ratio (N:Si:P = 16:16:1) in the rainwater might benefit from the growth of N-preference phytoplankton species and microbes. As the first study on N concentrations, sources, and stoichiometry balance in rainwater over the equatorial WPO and EIO, the results could be a support to the global N budget estimation and oceanic primary production modeling.
... The chemical characteristics of rainwater exhibit site-and region-specific variations, influenced by emission sources, local meteorology, geomorphology, and physical and chemical transformations [6,10,11]. The major ions present in rainwater originate from three primary sources: crustal sources (terrestrial dust), marine sources (sea-salt inputs), and anthropogenic sources (human emissions) [6,12]. ...
Rainwater is a vital water source with multiple applications, including domestic use. However, it also plays a crucial role in removing pollutants from the atmosphere, which can pose risks to ecosystems and human health. This study is aimed at assessing the levels of fluoride (F⁻) and nitrate (NO3⁻) ions in rainwater from different areas (industrial, urban, and rural/control) in the industrial city of Rio Grande, Brazil. Additionally, a Human Health Risk Assessment (HHRA) was conducted to investigate the non-carcinogenic risk associated with exposure to these ions in the rainwater samples. A total of 95 rainwater samples were collected and analyzed to evaluate spatial variations and potential contamination sources of fluoride and nitrate. The industrial area exhibited significantly higher concentrations of fluoride compared to the urban and control areas, emphasizing the influence of local industrial emissions. Furthermore, the distribution of fluoride and nitrate concentrations across different precipitation events in the study period demonstrated their relatively consistent levels throughout the year, with a notable increase in nitrate concentrations during the winter season. Importantly, our study is the first to identify and report non-carcinogenic risks to human health from exposure to fluoride concentrations in rainwater, with the industrial area being the most affected. Approximately half of the investigated samples, mainly from the industrial and urban areas, showed non-carcinogenic risk associated with fluoride contamination. However, the observed levels of nitrate did not pose non-carcinogenic risks in all samples. These findings highlight the potential health hazards posed by fluoride in rainwater, particularly in areas influenced by industrial activities and urban zones near industrial complexes. The findings highlight the hidden dangers present in rainwater and underscore the significance of monitoring and managing atmospheric pollution to safeguard both ecosystems and human well-being.
... In particular, the frequency of extreme temperature events in Romania increased significantly Birsan et al. 2019;Birsan et al. 2020;Busuioc et al. 2015;Dumitrescu et al. 2015). Various studies pointed out certain changes observed in the surface air temperature and precipitation regime (mean state and extremes) and their connection with changes in the large-scale circulation patterns (Tomozeiu et al. 2002;Ionita et al. 2013;Rimbu et al. 2015Rimbu et al. , 2016Nita et al. 2022b;Sfîcă et al. 2021;Szép et al. 2018;Țîmpu et al. 2020). The changes of the large-scale circulation types were investigated by Barbu et al. (2016a) and they noted that those changes can be linked to the increasing frequency of extreme weather events. ...
This study investigates the dominant large-scale air circulations that control the winter maximum temperature distributions over Romania. We focus on the winter frequency of circulation types determined from the Grosswetter-Types (GWT) classification methods. We applied an unmixing method based on non-negative matrix factorization (NMF) to cumulative distributions of monthly absolute maximum winter temperatures recorded at 163 Romanian weather stations between 1961 and 2013. This method can determine both the form of the end-members and their contributions using only the input maximum temperature distributions, giving access to extreme temperature distributions and providing further insight about the link between thermal extremes and large-scale atmospheric circulation. For comparison, we also fitted the generalized extreme value distribution (GEV) to the time series. Our findings show that the particular shape of the Romanian Carpathians divides the territory into two distinct climatological areas (the intra-Carpathian and the extra-Carpathian). The NMF method proved that all maximum winter temperature distributions from 163 Romanian meteorological stations could be entirely explained by only four end-members (EMs). Both the NMF and the GEV distributions can be explained by the interplay between circulations and orography. Hence, different circulation types combined with different orography could produce similar extreme temperature distributions.
... Zanieczyszczenia pochodzące z atmosfery i dostarczane z opadem atmosferycznym do geoekosystemu zlewni Różanego Strumienia miały wpływ na kształtowanie się składu chemicznego wody na kolejnych etapach jej obiegu. Na "wejściu" do geoekosystemu, z opadem dostarczane były do powierzchni terenu różne zanieczyszczenia pochodzące z atmosfery, na co wcześniej zwracali już uwagę Szép et al. (2018), Keresztesi et al. (2020) i Kotowski et al. (2020). Z kolei główny udział w materiale rozpuszczonym i odprowadzanym z obszaru zlewni Różanego Strumienia miały składniki związane z procesami wietrzenia chemicznego (Major et al., 2017). ...
The main aim of the work detailed here was to identify the level and composition of selected atmospheric pollutants supplied mainly with precipitation to the urbanized Różany Strumień catchment in Poznań, Poland; and to determine their impact on the chemical composition of water at subsequent stages of its circulation. The research was conducted in the hydrological years 2016-2020 as part of the Integrated Monitoring of the Natural Environment in Poland (ZMŚP) program, using the infrastructure of the ZMŚP’s "Poznań-Morasko" Base Station – of Adam Mickiewicz University in Poznań – the first such Base Station to be located within the boundaries of a large urban agglomeration. A key finding concerned a positive ion balance among nutrients supplied as a result of human activity (e.g. through fertiliser use) – involving NO3-, NH4+ and K+. Remaining chemical components (denudation ions) present in the waters circulating in the catchment are in turn characterised by a negative balance.
... Note: The unit of EC is μS cm − 1 , the unit of each ion is μeq L − 1 . Data are from: 1995-1998 (Feng et al., 2001) previous publications (Szép et al., 2018). In washing process, the atmospheric matters are strongly and effectively washed down during the early rain-stage, resulting in high ion contents in rainwater with the lower rainfall amount, that is, below-cloud processes. ...
Atmospheric pollution has become a global environmental issue, which caused a number of human health threats. It is therefore vital to understand the source-sink processes of air pollutants and their mechanisms. Rainwater is not only the major sink (removal process) of air pollutants, but also the good source tracer of atmospheric components. On the background of global climate changes, the extreme rainfall exerts a serious influence in megacity. However, the extreme rainfall driven chemical evolution of rainwater and its reflection on air pollution are rarely focused, even though it plays a significant role in urban-surficial ecosystem. To better understand the chemical evolution of urban extreme rainfall and their potential environmental effects, rainwater samples were collected in Beijing, a typical megacity, during the extreme rainfall period in 2021. Based on rainwater stoichiometry and historical comparison, the scouring process of air substance, the neutralizing process of rainwater and the ion sources were revealed. The findings showed that NH4+, NO3-, SO42-, and Ca2+ were four primary rainwater ions with distinct daily variations which were well removed by rainwater scouring process. The high values of NF (neutralization factor, ~2.2) and NP/AP (ratio of neutralizing to acidifying potential, ~1.8) suggested a relatively high level of rainwater neutralization. Source identification revealed that rainwater SO42- (94.9%) and NO3- (99.9%) were primarily originated from anthropogenic input, particularly the mobile emission sources (transportation), while sea salt input represented the major Cl- source (86.9%) and all Na+ source. By contrast, crust dust input was the main contributor of rainwater K+ (94.0%), Mg2+ (92.3%) and Ca2+ (98.2%), whereas NH4+ was considered only the contribution of human input (e.g., municipal feces and fossil fuel burning). This study clarified the chemical characteristics of extreme rainfall in megacity and highlighted the significant impact on urban environment, which will benefit the urban environmental management in the context of global climate change
... The marine contribution rates of K + were 9.36%, 5.3% and 20.56% in the three cities respectively, indicating that K + was basically terrestrial. Potassium can exist in soil in the form of coarse particles, and can also come from fine particles produced by biomass combustion and agricultural activities [43,44]. It is generally believed that Na + comes from the ocean and F − and NH 4 + come from human activities. ...
This work presents the results of a ten-year investigation (2010–2019) on the characteristics and sources of precipitation pollution in typical cities locating in the economic belt on the North Slope of Tianshan Mountain, Xinjiang. The water-soluble ions’ characteristics (Na+, NH4+, K+, Mg2+, Ca2+, F−, Cl−, SO42−, NO3−), neutralizing capacity, wet deposition and sources of precipitation in Urumqi, Karamay and Yining during 2010–2019 were compared and analyzed. The study showed that from 2010 to 2019, the pH value of precipitation in Urumqi, Karamay and Yining varied from 4.18 to 10.55 with a volume-weighted mean (VWM) pH of 6.33, and the pH value showed an upward trend overall. The VWM electrical conductivity (EC) of the precipitation was the highest in Urumqi and the lowest in Yining, indicating that Urumqi was the most polluted and Yining was relatively clean. The most important cation in the precipitation of the three cities was Ca2+, and the most important anion was SO42−. The ratio of SO42−/NO3− indicated that the air pollution in Urumqi and Yining belonged to the typical coal-smoke air pollution, while there was compound pollution in Karamay. As can be seen from the neutralization factor, Ca2+ had the strongest neutralization ability, followed by Na+ and NH4+. Nitrate and sulfate in the atmosphere of Urumqi, Karamay and Yining are likely to exist in the form of NH4NO3, CaSO4 and (NH4)2SO4•CaSO4•2H2O. Wet deposition flux analysis of S and N showed that S pollution of the precipitation in Urumqi showed a decreasing trend, while N pollution showed an increasing trend. S pollution of the precipitation in Karamay gradually decreased, while N pollution of the precipitation in Yining became more and more serious. By analyzing origins of major ions in precipitation, it is concluded that human activities (industry, agriculture, heating, and transportation) are the main sources of ions in precipitation, and natural sources (soil dust) also play an important role.
... Additionally, the indicators of air quality and air pollution, such as precipitation chemistry, change continuously. These changes can be related to the meteorological forcing and anthropogenic factors (Han et al., 2019;Mora et al., 2017;Ning et al., 2018;Szép et al., 2018). As the concentration of atmospheric pollutions and their distribution is affected by meteorological conditions (Ning et al., 2018;Xu et al., 2019), a direct impact on short-term variations in air quality is distinctive (Cao et al., 2020). ...
Lake Urmia, NW Iran, and S Caucasus region, has lost approximately three‐fourth of its water volume resulting in increased exposure of lacustrine deposits. Therefore, the role of Lake Urmia desiccated saline lands on local aerosols and rainwater compositions is still vague. This study investigates the temporal and seasonal patterns of rainwater chemistry from January 2018 to June 2018 (six months) in 13 stations throughout the Lake Urmia basin. The samples collected were analyzed using triple quadrupole inductively coupled plasma mass spectrometry (ICP‐QQQ) and ion chromatography (IC) to measure elemental and ionic concentrations. Then, the Hybrid Single‐Particle Lagrangian Integrated Trajectory model (HYSPLIT) was applied to identify the pathway and contribution of emissions. The results depict that the concentration of elemental and ionic components over different parts of the Lake Urmia basin are significantly different. West and north directions have the highest concentrations of marine ions associated with fewer toxic elements. In contrast, the east and south directions show a high concentration of heavy metal elements and ions. The high level of heavy and toxic elements at the east and south directions indicates that local anthropogenic sources are more influential. The seasonal and monthly variabilities of chemical compositions depict that the highest concentration of Na⁺, Mg²⁺, Ca²⁺, K⁺, Cl⁻, Br⁻, NO3⁻, Al, Cr, Mn, Fe, and Co were in the spring season and SO4²⁻, NH4⁺ and NO2⁻ were highest in winter. Seasonal variation for MSA, organic acids (i.e., Pyruvate, Adipate, and Oxalate), Ni, Cu, Zn, V, and Ti were not apparent. Cluster‐mean HYSPLIT backward trajectories results show the most dominant air mass sectors are from W (a: Iraq, Syria, and Arabian deserts; b: Mediterranean Sea; and c: KSA) and NE (the Caspian Sea and its vicinity), contributed to almost 65% and 22%, respectively. These air masses bring a significant quantity of crustal and marine aerosols, respectively. It is inferred that the Lake Urmia dried‐up lakebeds have less impact on the contribution of emissions across the region.
... Analisis parameter kimia untuk seluruh ion-ion dalam deposisi basah ini dilakukan dengan instrumen ion kromatografi (IC) dengan mempertimbangkan jenis kolom yang dimiliki. IC memiliki kelebihan sensitivitas, selektivitas, dengan waktu analisis yang relatif singkat (Dasgupta & Maleki, 2019;Michalski, 2016;Nesterenko & Paull, 2017 Chate & Devara, 2009;EANET, 2016;Szép et al., 2018;Thepanondh, 2004). ...
Dalam dekade terakhir, peningkatan konsumsi bahan bakar fosil yang berasal dari pembangunan ekonomi yang cepat dari sektor transportasi dan kegiatan industri telah menghasilkan emisi berbagai polutan udara. Hal tersebut menyebabkan masalah lingkungan di seluruh dunia, tak terkecuali di Indonesia. Deposisi asam yang diakibatkan oleh pencemaran udara masih merupakan isu wilayah di Asia. Jaringan Pemantauan Deposisi Asam di Asia Timur (EANET) yang mencakup Asia Timur Laut dan Tenggara, telah melakukan kegiatan pemantauan deposisi asam dan pengaruhnya terhadap ekosistem. Terdapat 5 (lima) lokasi pemantauan deposisi asam di Indonesia yang tergabung dalam EANET, yaitu Jakarta, Serpong, Bandung, Kototabang, dan Maros. Parameter air hujan yang dianalisis adalah pH, daya hantar listrik, Na+, K+, Ca2+, Mg2+, NH4+, Cl-, NO3-, dan SO42-. pH air hujan dapat mengindikasikan potensi terjadinya deposisi asam. Selama tahun 2015-2019, rata-rata tingkat keasaman air hujan di Jakarta, Serpong, Bandung, Kototabang, dan Maros masing-masing adalah 4,85, 5,17, 5,55, 5,23, dan 5,28. Meskipun masih terindikasi mengalami efek deposisi asam, nilai pH tersebut relatif lebih tinggi dibandingkan dengan periode sebelumnya. Potensi penyebab keasaman air hujan dapat dilihat melalui ion NO3- dan nss SO42-, sementara senyawa penetralisasinya adalah NH4+ dan nss Ca2+. Fraksi ekuivalen nitrat menunjukkan bahwa HNO3 yang lebih berpengaruh dalam terjadinya deposisi asam di Jakarta, Serpong, dan Bandung, tetapi di Kototabang dan Maros lebih disebabkan oleh H2SO4. Fraksi ekuivalen amonium di Kototabang menunjukkan bahwa peran CaCO3 lebih dominan dalam menetralisasi senyawa asam, sementara di kota-kota lainnya lebih didominasi oleh NH3. Kajian ini mengindikasikan bahwa dominasi sumber pencemaran berasal dari kegiatan antropogenik.
... The susceptibility of tailing dumps to wind erosion increases due to the artificially modified terrain, poor surface vegetation growth, and insufficient reclamation efforts [6]. The problem of air pollution not only at the global, but at the regional and local levels and its negative impact on the state of ecosystems and human health is a serious problem throughout the world [7][8][9][10]. ...
The article presents a study of the environmental impact of dusting tailing dumps of rare-metal ore dressing in the Murmansk region of Russia. The purpose of the study was to establish patterns in the atmochemical halo migration of the dust pollution of loparite ore dressing tailings. The geotechnical characteristics and material composition of the tailings material have been investigated. Potentially dusty areas identified. Models of dispersion of inorganic dust under different meteorological scenarios are constructed: at low wind load, normal and unfavorable meteorological conditions. The modeling of the spread of pollutants in the area exposed to dust at the storage site was carried out in the program for modeling atmospheric pollution Ecolog-4.60. Calculation of the dispersion of inorganic dust containing 20–70% SiO2 showed that the atmochemical halo of tailings dust pollution spreads over tens of kilometers, and already at a wind speed of about 8 m/s, the concentration of suspended solids at the border of the enterprise sanitary protection zone exceeds the maximum one-time maximum permissible concentration is 3–3.3 times, and under unfavorable meteorological conditions—Dusting reaches the boundaries of the residential area (inhabited locality Revda), located in the north-west of the enterprise, and exceeds the MPCm.o. 1.5 times.
... The studies of individual air quality index (IAQI) were also relatively few reported. Moreover, rainwater is an important sink of air pollutants (both gas and particulate pollutants) [18][19][20]. Air pollutants could be removed by both in-cloud (dissolution) and below-cloud (scour) processes, which further influenced rainwater chemistry and earth-surface ecosystem [6,21,22]. ...
Air pollutants have been investigated in many studies, but the variations of atmospheric pollutants and their relationship with rainwater chemistry are not well studied. In the present study, the criteria atmospheric pollutants in nine monitoring stations and rainwater chemistry were analyzed in karst Guiyang city, since the time when the Chinese Ambient Air Quality Standards (CAAQS, third revision) were published. Based on the three-year daily concentration dataset of SO2, NO2, CO, PM10 and PM2.5, although most of air pollutant concentrations were within the limit of CAAQS Ⅲ-Grade II standard, the significant spatial variations and relatively heavy pollution were found in downtown Guiyang. Temporally, the average concentrations of almost all air pollutants (except for CO) decreased during three years at all stations. Ratios of PM2.5/PM10 in non- and episode days reflected the different contributions of fine and coarse particles on particulate matter in Guiyang, which was influenced by the potential meteorological factors and source variations. According to the individual air quality index (IAQI), the seasonal variations of air quality level were observed, that is, IAQI values of air pollutants were higher in winter (worst air quality) and lower in summer (best air quality) due to seasonal variations in emission sources. The unique IAQI variations were found during the Chinese Spring Festival. Air pollutant concentrations are also influenced by meteorological parameters, in particular, the rainfall amount. The air pollutants are well scoured by the rainfall process and can significantly affect rainwater chemistry, such as SO42−, NO3−, Mg2+, and Ca2+, which further alters the acidification/alkalization trend of rainwater. The equivalent ratios of rainwater SO42−/NO3− and Mg2+/Ca2+ indicated the significant contribution of fixed emission sources (e.g., coal combustion) and carbonate weathering-influenced particulate matter on rainwater chemistry. These findings provide scientific support for air pollution management and rainwater chemistry-related environmental issues.
... Các ion kim loại kiềm và kiềm thổ là tác nhân trung hòa và cân bằng ion trong môi trường nước mưa. Tính chất axit hay bazơ của nước mưa là kết quả của sự cân bằng giữa các gốc axit, chủ yếu là SO4 2và NO3và gốc kiềm, chủ yếu là ammoni và muối calcium [2,[7][8][9]. ...
The acidity in rainwater is mainly controlled by the presence of H2SO4, HNO3 in combination with the ability to neutralize cations in rainwater. pH is an important value in the evaluation of acidity in rainwater. The research used a series of rainwater quality monitoring data from 2005 to 2018 in Vietnam. The research showed that the average pH distribution at 23 stations ranged from 5.83 ± 0.62. The rains with pH <5.6 appear in all years at the research stations. Considering the ability of acid neutralizing to various ions shows that Ca2+ is the main contributor to acid neutralization processes in rainwater, followed by Mg2 +, NH4+, and K+. While Ca2+ always play the highest acid neutralizing role at all stations; Depending on each station, Mg2+ and NH4+ ions play a role in neutralizing acidity in rainwater. The research also shows a match between the trend of H+ concentration and the tendency of cations to contribute to acid neutralization in rainwater.
... Cereals and animal feed in Central Europe [90][91][92][93][110][111][112]113]. The higher deoxynivalenol contamination in cereals in central Europe (southern Germany, the Czech Republic, western Slovakia and southwestern Poland) is due to precipitation caused by the intersection of Atlantic air masses with the "Vb" cyclones and low historical agroclimatic characteristics that have been amplified by extreme weather events in 2012-2014 ( Figure S.4) [19,54]. ...
This article aims to evaluate deoxynivalenol occurrence in triticale crops in Romania in years with extreme weather events (2012: Siberian anticyclone with cold waves and heavy snowfall; 2013 and 2014: “Vb” cyclones with heavy precipitation and floods in spring). The deoxynivalenol level in triticale samples (N = 236) was quantified by ELISA. In Romania, the extreme weather events favoured deoxynivalenol occurrence in triticale in Transylvania and the southern hilly area (44–47°N, 22–25°E) with a humid/balanced-humid temperate continental climate, luvisols and high/very high risk of floods. Maximum deoxynivalenol contamination was lower in the other regions, although heavy precipitation in May–July 2014 was higher, with chernozems having higher aridity. Multivariate analysis of the factors influencing deoxynivalenol occurrence in triticale showed at least a significant correlation for all components of variation source (agricultural year, agricultural region, average of deoxynivalenol, average air temperature, cumulative precipitation, soil moisture reserve, aridity indices) (p-value < 0.05). The spatial and geographic distribution of deoxynivalenol in cereals in the countries affected by the 2012–2014 extreme weather events revealed a higher contamination in Central Europe compared to southeastern and eastern Europe. Deoxynivalenol occurrence in cereals was favoured by local and regional agroclimatic factors and was amplified by extreme weather events.
... The identification of the air paths in wet deposition data analysis is important as this could provide information on possible sources and geographical areas linked to the interpretation of precipitation chemistry data. The relationships between cyclone activities and chemical characteristics of the atmosphere have sparked particular attention in various studies (Okay et al. 2002;Akkoyunlu and Tayanç 2003;Čanić et al. 2009;Szép et al. 2018). Gustafsson and Larsson (2000) have highlighted the importance of changes in cyclone activity due to climate change for the chemical characteristics of the midlatitude atmosphere. ...
The aim of this work is to study precipitation chemistry in the cross-border region between Turkey and Bulgaria, situated on the south-eastern part of the Balkan Peninsula. A total of 115 wet deposition samples were collected and analysed for pH values and major ions (Na⁺, Mg²⁺, Ca²⁺, K⁺, NH4⁺, Cl⁻, NO3⁻, and SO4²⁻) throughout the summer and autumn seasons of 2014. The enrichment factor analysis and non-sea salt estimates were conducted to determine the possible sources of ions in the wet deposition for the sampling period. The trajectories of the cyclones affecting the area during the study period were also analysed by separating them in different groups. The minimum, average and maximum pH values for the first group of cyclones (CG1) are 4.30, 6.04, 7.40, and 4.00, 6.14, 7.43 for the second group cyclones (CG2), respectively. The non-sea salt fractions of the K⁺ ion were found to be 0.94 in CG1 and 0.90 in CG2. Also, the Mg²⁺ ion in CG1 and CG2 is 44% and 60% of the sea salt source.
... Based on information in the study, it is indicated that biosynthetic production should be used [4]. Use of sustainable raw materials instead of petrochemicals is of great importance, in order to reduce the negative health, social and economic impact of air pollution, as well as to contribute to the development of circular economy [5][6][7][8][9][10][11][12][13][14][15]. Ferone et al. reports that high-sugar-content beverages (HSCBs) can be used for succinic acid production [16]. ...
Succinic acid production through biological fermentation led to new pathways in the integration of renewable feedstock from different industries into biosynthesis. In this article, we investigate the population growth dynamics and succinic acid production potential of the recently isolated natural succinic acid producer, Basfia succiniciproducens, using in silico constraint-based metabolic models as well as in vitro experiments. Our work focuses on the influence of different renewable substrates and added yeast extract on fermentation dynamics, and the produced metabolites of the strain cultured in mineral (minimal) medium. According to our experiments, which were carried out as small-scale fermentations and in bioreactor conditions, glucose is the preferred carbon source, while the addition of 1% yeast extract has a significant positive effect on biomass formation. In the case of B. succiniciproducens cultured in minimal salt medium, a production potential as high as 47.09 mM succinic acid was obtained in these conditions. Industrial applications related to this bacterial strain could contribute to new possibilities for the re-use of byproducts by using fermentation processes, leading to high added-value compounds.
... Atmospheric pollution is a growing issue worldwide, adversely affecting both the human health and the ecosystem as well (Castillo et al., 2017;Keresztesi et al., 2018;Szép et al., 2018). Many epidemiological studies argue that particulate matter (PM) has become a decisive parameter of air pollution (Jena & Singh, 2017) and therefore can play an essential role in the chemical composition of precipitation (Keresztesi et al., 2020b. ...
In the present study, the concentrations of trace elements in PM 10 were determined and analyzed at 115 monitoring stations in Romania throughout the period 2009–2018. The spatiotemporal distribution of trace element concentrations of PM 10 , the source apportionment and health impact assessment, was carried out. The results showed a very high multi-annual mean concentration for PM 10 and trace elements as well. The multiannual average concentration of PM 10 was higher by 29.75% than the World Health Organization recommendation. All studied air pollutants showed a decreasing trend during the studied years, showing with 17.84%, 50.21%, 43.36%, 11.27%, and 72.09% lower values for PM 10 , As-, Cd-, Ni-, and Pb-, respectively, due to environmental regulations. To assess the human health impact, the hazard quotient (HQ) and cancer risk (CR) were calculated using the health risk model developed by the US Environmental Protection Agency (EPA). The Cd and Ni might present a non-carcinogenic risk to both adults and children; however, the hazard quotient values are higher than the safe limit, with 9.53 and 1.93, respectively. In addition, our study results revealed that the inhalation of As, Cd and the dermal absorption of all studied trace elements were considered as the most important risk factors for developing cancer, especially in case of adults.
... The chemical composition of rainwater provides information on the atmospheric quality in a specific region that depends on emission sources, atmospheric chemistry, and meteorological conditions (Zunckel et al. 2003). Rainwater chemistry helps to understand the relative contribution of different pollutant sources (crustal, marine, anthropogenic, and natural) to atmospheric chemistry (Szép et al. 2018Niu et al. 2018) and reflects various interacting physical and chemical mechanisms in the atmospheric transport and removal processes (Kulshrestha et al. 2005;Galy-Lacaux et al. 2009). Rainwater contains both natural (sea salt and soil dust) and anthropogenic (gases emitted from industrial areas and vehicles) species (Tiwari et al. 2007;Niu et al. 2014). ...
The nature and sources of ionic species were studied in the monsoon rainwater collected from two monuments of the sixteenth–seventeenth century CE in the Yamuna River basin from 2016 to 2018. The results showed the acidic pH of the rainwater with high dissolved SO4−2 and NO3−, and soil-derived components (Ca+2, Mg+2, and K+). The anionic (SO4−2, NO3−, Cl−, F−, and HCO3−) and cationic (Ca+2, Mg+2, K+, NH4+, and Na+) concentrations showed regional differences in yearly contribution mainly from the fossil fuel combustion, soil dust, and farm residue burning. The rainwater analysis showed low dissolved ions at SCTK (Sheikh Chilli’s Tomb, Kurukshetra) compared to KBMP (Kabuli Bagh Mosque, Panipat). The mean concentration of SO4−2 was 1.5 times higher than the NO3− apportioning the sulfate as a dominant acidifying constituent in rainwater. Pearson’s correlation and principal component analysis (PCA) showed terrestrial and marine origins of dissolved ions in the rainwater. The Na-normalized molar ratios and the analysis of sea salt and non-sea salt fractions indicate the dominance of non-marine contributions in the precipitation. Based on neutralization factors, cations showed neutralization of rainwater acidity as follows: NFCa+2 > NFMg+2 > NFNH4+ > NFK+. The potential index showed the dominance of the neutralization potential (NP) on acidic potential (AP) at both locations.
... The major water-soluble constituents of the measured aerosols were sulfate, chloride, sodium, and calcium, cumulatively accounting for 88.19%, 88.25%, and 91.29% of the total mass concentration of PM 2.5 , PM 10 , and TSP, respectively. Chloride, sodium, and calcium are typically associated with crustal matter (e. g., CaCl 2 ) and also sea salt (e.g., NaCl), with the latter possible based on evidence from other regions of sea salt being transported inland from the sea (Corral et al., 2020;Grimshaw and Dolske, 2002;Junge and Werby, 1958;Ma et al., 2021;Szép et al., 2018). Crustal constituents are expected to be more abundant than sea salt owing to the concentrated amount of the former at the GEG facility. ...
This study characterizes the hygroscopic and chemical nature of aerosols originating from ten locations (4 outdoors and 6 indoors) around the Gol-E-Gohar (GEG) iron ore mine (Iran), including an assessment of how hygroscopic growth alters particulate deposition in the respiratory system. Aerosols collected on filters in three diameter (Dp) ranges (total suspended particulates [TSP], Dp ≤ 10 μm [PM10], and Dp ≤ 2.5 μm [PM2.5]) were analyzed for chemical and hygroscopic characteristics. The water-soluble aerosol composition is dominated by species associated with directly emitted crustal matter such as chloride, sodium, calcium, and sulfate. There was minimal contribution from organic acids and other secondarily formed species such as inorganic salts. Aerosol growth factors at 90% relative humidity varied between 1.39 and 1.72 and exceed values reported for copper mines in the United States where similar data are available. Values of the hygroscopicity parameter kappa (0.19–0.45) were best related to the mass fraction of chloride among all the studied species. Kappa values were generally similar when comparing the three types of samples (TSP, PM2.5, PM10) at each site and also when comparing each of the ten sampling sites. Accounting for hygroscopic growth yields an increase in the deposition fraction for aerosols with a dry Dp between 0.2 and 2 μm based on International Commission on Radiological Protection model calculations, with more variability when examining each of the three individual head airway regions.
... The lifting condensation level variation also plays an essential role in particulate matter variation. Many studies show the effect of precipitation washout by comparing the PM10 concentration with the precipitation and non-precipitation periods [9], [15], [16]. The air pollutant (PM10) reduction efficiency by precipitation scavenging depends on the precipitation quantity and duration [8]. ...
The PM10 concentration reduction caused by large-scale precipitation in the Ciuc Basin was studied under no-wind conditions. The PM10 concentration changing before, during, and after the rainfall was followed up from 2008 to 2019. After the rainfall episode, the PM10 concentrations were lower in the cold and warm periods with 2.8 μg/m 3, and 2 μg/m 3 respectively. The highest PM10 concentration reduction was detected in the cold season, by the moderate and light rain intensity, after 6 hrs of continuous rain (35.61%, 32.46%), and the average PM10 concentration reduction in the cold and warm periods was 22.3% and 16.1% respectively.
... This site is important in this study because of its high elevation (3399 m ASL) as topographical features can impact wet deposition chemistry. For instance, measurements based at the Carpathian Mountain chain in Romania showed that there was blockage of transported aerosols, such as sea spray, as confirmed by a lack of correlation between commonly linked sea salt species such as Mg 2+ and Na + (Szep et al., 2018). Mauna Loa's high altitude reduces the influence of short lived pollutants from near the surface such as primary marine aerosols (Keene et al., 2015). ...
This study examined spatial variations of precipitation accumulation and chemistry for six sites located on the West and East Coasts of the U.S., and one site each on the islands of Hawaii, Bermuda, and Luzon of the Philippines (specifically Manila). The nine coastal sites ranged widely in both mean annual precipitation accumulation, ranging from 40 cm (Mauna Loa, Hawaii) to 275 cm (Washington), and in terms of monthly profiles. The three island sites represented the extremes of differences in terms of chemical profiles, with Bermuda having the highest overall ion concentrations driven mainly by sea salt, Hawaii having the highest SO4²⁻ mass fractions due to the nearby influence of volcanic SO2 emissions and mid-tropospheric transport of anthropogenic pollution, and Manila exhibiting the highest concentration of non-marine ions (NH4⁺, non-sea salt [nss] SO4²⁻, nss Ca²⁺, NO3⁻, nss K⁺, nss Na⁺, nss Mg²⁺) linked to anthropogenic, biomass burning, and crustal emissions. The Manila site exhibited the most variability in composition throughout the year due to shifting wind directions and having diverse regional and local pollutant sources. In contrast to the three island sites, the North American continental sites exhibited less variability in precipitation composition with sea salt being the most abundant constituent followed by some combination of SO4²⁻, NO3⁻, and NH4⁺. The mean-annual pH values ranged from 4.88 (South Carolina) to 5.40 (central California) with NH4⁺ exhibiting the highest neutralization factors for all sites except Bermuda where dust tracer species (nss Ca²⁺) exhibited enhanced values. The results of this study highlight the sensitivity of wet deposition chemistry to regional considerations, elevation, time of year, and atmospheric circulations.
... With these modifications the carbon and energy flux cannot be connected to the new biosynthetic pathway efficiently, as long as large amount of carbon is lost in form of L-valine (amino acid secreted into the medium). One reason could be that the flux through ppc (phosphoenolpyruvate carboxylase) and even pdh (pyruvate dehydrogenase) is not high enough to consume all the pyruvate generated (pfl, ldh were eliminated-e.g. the lactate pathway allosteric activation is blocked), resulting in L-valine overflow [81]. To decipher the optimal knockouts, simulations were carried out in a manner similar to that used for glucose, using two, three and four knockout designs. ...
Bio-based, environmentally benign production of commodity chemicals such as 1,4-butanediol (BDO) from renewable feedstocks is highly challenging due to the lack of natural synthesis pathways. Herein, we present a systematic model-driven evaluation of the production potential for Escherichia coli to produce BDO from renewable carbohydrates (glucose, glycerol). Computational analysis was carried out in order to decipher the metabolic characteristics under various genetic and environmental conditions. Optimal strain designs were achieved using only two (adhE2- alcohol dehydrogenase and cat/sucCD- 4-hydroxybutyrate-CoA transferase/4-hydroxybutyryl-CoA ligase) heterologous reactions; highest yields were attained for: glucose ~0.37 g g-1 (3 knockouts, anaerobically) and glycerol ~0.43 g g-1 (4 knockouts, microaerobically). The maximum achievable production yield was over 95% of the theoretical maximum potential for glucose and over 75% for glycerol. In regards to the genome-scale metabolic model predictions, a metabolically engineered E. coli was created to analyze the new biosynthetic pathway stability and functionality. Considering the preliminary outcomes the strain and pathway is stable under fermentative conditions and a limited quantity of BDO ~1 mg L-1 was obtained, therefore long-term adaptive evolution is mandatory. This study outlines a strain design and analysis pipeline -systems biology-based approach- for non-native compounds production strains.
... One of the reasons why higher levels are measured during the cold season is that it is not only caused by heating (which has a seasonal characteristic) but also by the atmospheric stability and thermal inversions that characterize this region (intra-mountain basin). Therefore, with the heating time, the concentration of gaseous pollutants, SO 2 , NO 2 , NO, NO x , and on the other hand CO, increases due to thermal inversion (Szép et al. 2018. According to the results, the best air quality was recorded in summer months, while for winter, the ambient air quality is decreasing; nonetheless, the daily mean concentration of pollutants was below the legal limit. ...
The air quality decrease, especially in urban areas, is related to local-scale conditions and to dispersion of air pollutants (regional and
long-range) as well. The main objective of this study was to decipher the seasonal variation of PM10, NO, NO2, NOx, SO2, O3, and
CO over a 1-year period (2017) and the possible relationships between air pollution and meteorological variables. Furthermore,
trajectory cluster analysis and concentration-weighted trajectory (CWT) methods were used to assess the trajectories and the sourcereceptor
relationship of PM10 in the Ciuc basin Transylvania, known as the “Cold Pole” of Romania. The pollutants show lower
concentrations during warmer periods, especially during summer, and significantly higher concentrations were observed on heating
season in winter due to seasonal variations in energy use (biomass burning) and atmospheric stability. Subsequently, in February,
the highest concentration of PM10 was 132 μg/m3, which is 4 times higher than the highest recorded monthly mean. Our results
indicate a negative correlation between CO/temperature (− 0.89), NOx/temperature (− 0.84) and positive between NOx/PM10 (0.95),
CO/PM10 (0.9), and NOx/CO (0.98), respectively. Dominant transport pathways were identified and the results revealed that slowmoving
southerly (~ 45%) and northwesterly (~ 32%) air masses represent almost 80% and mainly regional flows were discerned.
During 2017, increased PM10 levels were measured at the study site when air masses arrived mostly from northwest and southeast.
The CWT and polarplot models show a strong seasonal variation and significant differences were observed between weekdays and
weekends, namely highest PM10 concentrations during weekends at low wind speed (2–4 m/s).
... The chemical synthesis through catalytic hydrogenation of maleic acid is highly dependent on fossil resources, which gives rise to major concerns about sustainability. On the other hand, the environmental pollution even at regional levels should be taken into consideration (ILIE & al [42]; KERESZTESI & al [43]; SZÉP & al [44][45][46][47][48][49][50]). Taken together, biotechnology offers new sustainable alternatives, however, there are still many questions to be answered in order to better understand the interactions inside a cell, especially if different genetic modifications are carried out or the environmental conditions are modified. ...
... The climatic changes in Romania have been showing their environmental, societal and economic effects visibly over the last decades. Several recent climate studies relying on long-term observational time-series provided reliable evidence of a robust and ongoing warming in summer, winter and spring [4], increasing rain shower frequency [5,6], decrease in winter snow depth [7,8] and in wind speed [9]; these changes have been found to affect drought patterns [10][11][12], natural streamflow regime [13,14] and even the composition of rainwater [15][16][17] in many regions across the country. Observational analyses of the variability and trends of extreme events suggest an overall consensus towards a significant increase in the frequency, duration and intensity of warm extremes and intensification of bioclimatic heat stress in the region [18][19][20][21]. ...
In order to identify changes in the annual temperature extremes, the Mann-Kendall non-parametric trend test has been applied to several thermal indices, recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI). The indices were computed from gridded daily data of minimum and maximum temperature at 0.1° resolution (~10 km), freely available within the ROCADA dataset for the period 1961-2013. The results show decreasing trends in cold-related indices, especially in the number of frost days, and increasing trends in warm-related extremes. The trend patterns are consistent over the region, i.e., there are no mixed trends for a given index. The regional differences in climatic trends over Romania are related to altitude, rather than latitude. The key findings suggest a country-wide increasing frequency of summer days, an increase of tropical nights frequency at lower elevations, a reduction of frost season and a widening of the growing season in the extra-Carpathian regions. The duration of warm spells have been increasing over most of Romania. Our results are in agreement with previous temperature-related studies in the region.
Mexico City Metropolitan Area (MCMA), one of the most populous cities in the world, has historically represented a challenge in terms of air pollution. Particulates and sulfur dioxide.
(SO2) were identified as the main atmospheric pollutants three decades ago. In order to reduce emissions of these pollutants, replacing of fuel oil by natural gas in power plants was carried out in the late 1980s. This strategy resulted in the reduction of ambient air concentrations of both pollutants. SO2 no longer exceeds its ambient air quality standard; however, acid rain remains a significant issue, with sulfate remaining as the principal component in the wet atmospheric deposition.
In this study, spatial and temporal variations in the chemical composition of precipitation (sulfate and nitrate ions, and pH) were obtained weekly at 16 sampling stations, as well as atmospheric SO2 and nitrogen oxides (NOx) from an air quality monitoring network from 2003 to 2018 in the MCMA. Some indicators were applied to evaluate wet atmospheric deposition: SO4²⁻/NO3⁻ and NH4⁺/NO3⁻ ratios, fractional acidity as well as neutralization factors.
SO2 ambient air concentrations have decreased from 2003 to 2018 by more than 70%, while NOx has decreased by 20%. The SO2/NOx ratio has declined about 60%, indicating more effective strategies in reducing SO2 than for NOx emissions. The NOx emission sources are more diverse than for SO2, and NOx has more complex mechanisms of atmospheric deposition and photochemistry.
The pH values of the samples at the stations located in the south were more acidic than the samples for the stations in the north. This result is in line with meteorological conditions, where prevailing winds blow from north to south, as well as emission sources located in the north sector, both inside and outside MCMA. For SO4²⁻/NO3⁻ ratio, all sampling sites present current values in the same magnitude order, around 1.4, which is higher compared with urban sites in USA. The 2018 NH4⁺/NO3⁻ ratio was 1.98 for the southern sampling site, while all northern sampling sites were approximately 2.28. These results are on the same order that urban sites in USA. It was concluded that ammonium was a very important neutralizing agent of pH within the MCMA precipitation.
It is recommended to apply strategies for the emissions reduction of acid rain precursors in external sources to the North the MCMA, and to establish a Network for Urban Atmospheric Nitrogen Chemistry.
Bu çalışmada, Antalya ili Akdeniz Üniversitesi Kampüs alanında 2020 yılında toplanan fraksiyonel numunelerdeki suda çözünmeyen partiküllerin morfolojik yapılarının, boyut dağılımlarının ve kimyasal bileşimlerinin karakterize edilmesi amaçlanmıştır. Ayrıca her bir yağmur olayının fraksiyonel (sıralı) örneklerinde majör iyonlar ve bu iyonların fraksiyonel dağılımları, nötralizasyon faktörleri belirlenmiş, bulutla taşınan (rainout) ve bulut altı yıkama (washout) mekanizmaları ile hangi oranlarda alıcı ortama geldikleri hesaplanmıştır. Çalışmada kullanılan üç yağmur olayından birisi olan D-serisi, 07.12.2020 tarihinde örneklenmiş ve bu yağmur olayından 4 adet fraksiyonel örnek toplanmıştır. 10.12.2020 tarihli E-serisine karşılık gelen yağmur olayında ise 8 adet ve 12.12.2020 tarihli F-serisi yağmur olayında da 10 adet fraksiyonel yağmur suyu örnekleri toplanmıştır. Elde edilen sonuçlar çeşitli istatistiksel programlar ile değerlendirilerek, çıkan sonuçların veri kaliteleri ve kaynak belirleme çalışmaları yapılmıştır. Örneklerde ortalama pH değerleri 6.06-7.13 aralığında gözlemlenmiş ve herhangi bir şekilde asit yağmuru olasılığına rastlanılmamıştır. Yağmur örneklerinde partikül boyut analiz sonuçlarında D-serisi örneklerde en yüksek ölçülen değer 33.339 µm, E-serisi örneklerde 53.714 µm olarak ölçülmüştür ve F serisi örneklerde ölçüm yapılamamıştır. Örneklenen yağmur olaylarının taşınım bölgelerinin belirlenebilmesi için geri yörünge hesaplamaları yapılmış, kaynak bölgeleri, kaynak türleri ve kirletici içerikleri tartışılmıştır.
The present research has been performed to analyze the chemical behavior of rainwater of the Shaune Garang catchment (32.19° N, 78.20° E) in the Baspa basin, located at a high elevation (4221 m above mean sea level) in the Himachal Himalaya, India. During the study period, sixteen rainwater samples were collected from the Shaune Garang catchment at five different sites. The volume-weighted mean (VWM) pH value of rainwater ranged between 4.59 and 6.73, with an average value of 5.47 ± 0.69, indicating the alkaline nature of rainfall. The total ionic strength in the rainwater ranged from 113.4 to 263.3 µeq/l with an average value of 169.1 ± 40.4 µeq/l. The major dominant cations were Ca²⁺ (43.10%) and Na⁺ (31.97%) and anions were Cl⁻ (37.68%), SO4²⁻ (28.71%) and NO3⁻ (23.85%) in rainwater. The ionic ratios were calculated among all the ions. The fraction of (NO3⁻ +Cl⁻) with SO4²⁻ was measured as 2.3, which specifies sour faces of rainwater due to HNO3, H2SO4, and HCl. A multivariate statistical assessment of rainwater chemistry through Principal Component Analysis (PCA) shows the significance of four factors controlling 78.37% of the total variance, including four-component (PC1 explained 27.89%, PC2 explained 24.98%, PC3 explained 14.64%, PC4 explained 10.85%). However, the individual contribution of Factor 1(PC1) explains 27.89% of the total variance (78.37%) and displays a strong optimistic loading for Ca²⁺ and Cl⁻. Further, high loading of Ca²⁺ and NO3⁻ and moderate loading of SO4²⁻ signify the contribution of burning fossil fuel and soil dust. Anthropogenic and natural pollutants influence the composition of rainwater in the pristine Himalayas due to local and long-distance transportation. The study area receives precipitation from the West and North-West, transporting dust and fossil fuel emissions from the Thar Desert and Northwestern countries.
The results of rainwater chemistry monitoring in the Tatra Mountains, Poland, during the periods1993–1994 and 2002–2019 were used to determine long-term trends and the factors influencing rainwater chemistry in the last two decades. In the early 1990’s, the study area was characterized by prominent acid rains with a pH of 4.4 that affected surface water, meadows, and forest ecosystems. A rising pH temporal trend has been observed during the following years, indicating improving air quality. This trend has also been observed in measured ionic concentrations and reduced wet deposition loads of sulfur- and nitrogen-containing acid-forming compounds. The neutralization capacity of rainwater in Kasprowy Wierch increased over the last twenty years and has mostly been dominated by NH4+. The ammonium availability index has been steadily increasing between years 2002 and 2019 but remains less than 1. This statistically significant relationship also indicates that a portion of neutralization occurs in the lower part of the atmosphere due to ammonium-related neutralization processes. The acidic potential (AP) and the ratio AP/NP (acidic potential/neutralization potential) have been declining during the same time. The stated trends in rainwater chemistry reflect the transformation to more environmentally sustainable economies in the region. Similar changes have been observed in neighboring countries in the region, including Slovakia, the Czech Republic, and Lithuania.
In order to reduce the energy consumption of sensor transfer nodes in atmospheric environment monitoring, the energy-saving configuration of embedded sensor transfer nodes in the Internet of Things (IOT) for dust movement monitoring in the atmospheric environment is proposed. Firstly, the wireless sensor network technology is analyzed. Combined with the characteristics of data transmission in the process of dust movement monitoring in the atmospheric environment, the energy-saving configuration of an embedded sensor transfer node in the Internet of Things is designed, and sleep scheduling is introduced into the data transmission module. According to the spatial correlation of dust movement in the atmosphere, different state areas are divided, and the optimal node is selected as the representative node of the monitoring area data transmission to reduce energy consumption of nodes. The simulation results show that the time of dead nodes is about 150 rounds, and the energy consumption is kept at 0.0025J/round, and it is basically stable without obvious energy consumption fluctuation. It realizes the energy saving of specialized nodes in sensors and improves the operation life of sensor networks. It has certain research value.
Long-term and frequent observation of rainwater chemistry provides an opportunity to explore the evolution of air pollutant emissions and the effectiveness of the emission control measures. This study presents variations in rainwater chemistry, possible sources of air pollutant emissions, and wet deposition fluxes of ionic species in the rainfall samples during 2018–2020 at Mt. Lushan located in South China. Results showed that the annual volume-weighted mean (VWM) pH of rainwater was 5.8. Moreover, the VWM of 87.7% rainwater samples had pH values above 5.6, which indicated that the atmospheric pollution at Mt. Lushan had less effect during the study period. The polytonic nitrate ion (NO3⁻), the doubly charged positive calcium ion (Ca²⁺) and the ammonium ion (NH4⁺) were the dominant ions in rainwater where Ca²⁺ and NH4⁺ were the main neutralizing ionic species for rainwater acidity. The highly seasonal variability of ionic concentrations in rainwater was observed among different ionic species, which is closely associated with meteorological conditions and anthropogenic emissions present in the various seasons. Annual wet deposition flux showed an increasing trend during the entire periods. Hence, the wet flux of NO3⁻ (76.3 kg ha⁻¹ yr⁻¹) was three times higher than the annual wet deposition flux of sulfate (SO4²⁻, 21.7 kg ha⁻¹ yr⁻¹), which points to the fact that acid deposition is still a severe environmental issue in the Mt. Lushan region. Positive matrix factorization (PMF) and correlation matrix were used to identify five sources for ionic species, including aging sea salt, fossil fuel combustion, agriculture, dust, and biomass burning. These findings could be helpful in establishing emission control policies to protect and manage pollution control in the eco-environment in South China.
Rainwater chemistry of extreme rain events is not well characterized. This is despite an increasing trend in intensity and frequency of extreme events and the potential excess loading of elements to ecosystems that can rival annual loading. Thus, an assessment of the loading imposed by hurricane/tropical storm (H/TS) can be valuable for future resiliency strategies. Here the chemical characteristics of H/TS and normal rain (NR) in the US from 2008 to 2019 were determined from available National Atmospheric Deposition Program (NADP) data by correlating NOAA storm tracks with NADP rain collection locations. It found the average pH of H/TS (5.37) was slightly higher (p < 0.05) than that of NR (5.12). On average, H/TS events deposited 14% of rain volume during hurricane season (May to October) at affected collection sites with a maximum contribution reaching 47%. H/TS events contributed a mean of 12% of Ca²⁺, 22% of Mg²⁺, 18% of K⁺, 25% of Na⁺, 7% of NH4⁺, 6% of NO3⁻, 25% of Cl⁻ and 11% of SO4²⁻ during hurricane season with max loading of 77%, 62%, 94%, 65%, 39%, 34%, 64% and 60%, respectively, which can lead to ecosystems exceeding ion-specific critical loads. Four potential sources (i.e., marine, soil dust, agriculture and industry/fossil fuel) were indicated by PCA. The positive matrix factorization (PMF) suggested Mg²⁺, Na⁺ and Cl⁻ were primarily marine-originated in both event types, while 36% more sea-salt Ca²⁺ and 33% more sea-salt SO4²⁻ were deposited during H/TS. Agriculture and industry/fossil fuel were the main sources of NH4⁺ and NO3⁻, respectively, in both rain event types. However the NH4⁺ contribution from industry/fossil fuel increased by 13% during H/TS indicating a potential vehicle source associated with emergency evacuations. This work provides a comprehensive assessment of the rainwater chemistry of H/TS and insight to expected ecosystem loading for future extreme events.
Observations of particulate matter less than 10 μm (PM10) were conducted from January to December in 2015 in the Ciuc basin, Eastern Carpathians, Romania. Daily concentrations of PM10 ranged from 10.90 to 167.70 μg/m3, with an annual mean concentration of 46.31 μg/m3, which is higher than the European Union limit of 40 μg/m3.
Samples were analyzed for a total of 21 elements. O, C and Si were the most abundant elements accounting for about 85% of the PM10 mass. Source identification showed that the elemental composition of PM10 is represented by post volcanic activity, crustal origin, and anthropogenic sources, caused by the resuspension of crustal material, sea salt and soil dust. The average PM10 composition was 72.10% soil, 20.92% smoke K, 13.84% salt, 1.53% sulfate and 1.02% organic matter. The back-trajectory analysis showed that the majority of PM10 pollution comes from the West, Southwest and South.
The aim of this work is to evaluate the atmospheric rainwater chemistry and neutralization potential in oil producing areas of southern region of Nigeria. Rainwater samples were analysed for pH, EC, Cl⁻, SO4²⁺, NO3⁻, Ca2⁺, and NH4⁺. Correlation, principal component analysis (PCA) and neutralization indicators as source apportionment methods were used to determine atmospheric acid precursors . Results show that the collected samples were severely acidified with pH value of 5.5 in oil producing communities and weak acid: pH 6.5 in non oil producing areas and varied with seasons. Fractional acidity (FA) constituted 98–99% of neutralizing ability, neutralization factor (NF) recorded Cl⁻, Ca²⁺ and NH4⁺ in values of 0.41, 0.43 and 0.003 with Ca²⁺ from sea salt, being the most neutralizing substance than NH4⁺from agricultural practice. The neutralizing and acidifying potentials (NP/AP) recorded a mean of 0.4, showing weak alkaline effect on atmospheric acid rain in oil producing communities. The positive correlation among ionic species implicates pH, SO4²⁺and NO3 as causes of severe atmospheric acidity. Conclusions were made that enforcement of the existing environmental laws to checkmate the emission of acid precursors is crucial for the survival of man and entire ecosystem.
The concentration of ions, metals, and metalloids in hailstone samples was evaluated for the first time in South America. The samples were previously cleaned with ultrapure water to eliminate potential contaminants. The ions concentrations in the samples showed a general pattern according to the following sequence: Ca²⁺ ˃ NO3-> K⁺ > CHOO⁻ > Mg²⁺ > Cl⁻ > SO42_> Na⁺ > NH4+ > F⁻. Regarding the metals and metalloids concentrations, the order was of Zn > Al > Fe > Mn > Sr > Ba > Cu > Ni > Cr > Pb > Co > V. Ca²⁺ was the most abundant and agricultural activity, one of the sources due to long-distance transport. Concentrations of K⁺ and Cl⁻ may originate from fires that occur every year in the North and Center-West regions of Brazil. Local sources also contributed to the chemical composition, such as soil resuspension contributing mainly to the species and elements Al, Fe, Na⁺, K⁺, SO42_, and F⁻. Besides that, the region is an agricultural area with unpaved roads and use of fertilizer; therefore, the species and elements NH4+, Mg²⁺, K⁺, Cl⁻, Cu, and Zn, were also associated with local sources, including emissions from vegetation. A possible vehicular contribution was also observed. Among the few existing studies, this is the first to evaluate the hailstones cleaning procedure's efficiency. The findings also support the previous studies' conclusion that the concentration of chemical species varies considerably according to the region of study's characteristics. This work contributes to improve the understanding of local and remote natural and anthropic emissions in this complex atmospheric phenomenon.
The quantitative and qualitative characterization of ions and inorganic nitrogen in precipitation assists in understanding the accompanying sources and chemistry of regional precipitation. A total of 212 event-based precipitation samples were collected from four sites in Bangladesh in 2017 to investigate the physicochemical characteristics, sources, and deposition of atmospheric ionic constituents and inorganic nitrogen. During the entire monitoring period, 5.7% of the total samples were acidic (i.e., pH < 5.6), indicating that Bangladesh does not suffer severely from acid rain. The electrical conductivity (EC) and total dissolved solids (TDS) values indicate the inverse relationship between the amount of precipitation on the spatiotemporal scale. Ca 2+ was the dominant neutralizing factor at four sites, which was demonstrated by the equivalent ratio of the neutralization potential to the acidifying potential and fractional acidity. Moreover, it had the highest volume-weighted mean concentration of all the sites, validating the calcareous nature of the soil aerosolized into the atmosphere. Distinct seasonality was observed for the majority of the ions with higher concentrations in the non-monsoon climate. Sea salt species displayed the pattern of Satkhira > Cox's Bazar > Dinajpur > Sylhet, whereas the anthropogenic species exhibited the order of Dinajpur > Satkhira > Sylhet > Cox's Bazar, underlining the local and regional impacts of these species in Bangladesh. Based on the source apportionment, the sources were categorized as marine (Na + and Cl −), terrigenous (Ca 2+ , Mg 2+ , and HCO 3 −), fossil fuel combustion (NO 3 − and SO 4 2−), agriculture (NH 4 +), and biomass burning (K +). The Cl − in Sylhet and Satkhira suggests additional sources associated with anthropogenic activities. The back-trajectory analyses and the National Centers for Environmental Prediction's final (NCEP FNL) datasets illustrate the presence of significantly diverse air masses with contributions from various sources in the monsoon and non-monsoon climates. Both the amount of precipitation and the ionic quantity governs the fluxes in Bangladesh. The Na + % and SAR lie under the safe category suggesting a good precipitation water quality for agriculture and soil in Bangladesh, while the deposition of inorganic nitrogen has resulted in a value above the threshold line (10 kg ha − 1 y − 1). Thus, this study conveys a comprehensive picture of the ionic composition, providing a baseline dataset to assess the atmospheric environment in this lowland region.
This study presents the assessment of the PM10 emissions in areas from the south of Bucharest and Ilfov county, for a period of 11 years, during 2008-2018, taking into consideration the most important meteorological parameters with influence to air pollution, such as relative humidity, temperature, wind direction, and wind speed. During the study period, the mean annual concentrations of PM10 decreased from 43.92 μg/m 3 to 29.67 μg/m 3 , expressed as a percentage change the decrease was 35.45% and 29.03% at the B-4 and B-7 stations, respectively. The Pearson correlation coefficient was significantly higher in the cold season (November-April). In order to further investigate the relations of air quality and wind direction pollution roses were calculated and the results indicate that the highest concentrations of PM10 occur in B-4 and B-7 at the southwestern and west direction of wind.
A study of ions sources and water vapor sources was carried out from April 1, 2016 to October 31, 2018, at Zhimenda(ZMD), Qumalai(QML) and Tuotuohe(TTH) in the source region of the Yangtze River to obtain preliminary quantitative results for the contributions of the ion and water vapor sources. In the study, 489 precipitation samples analyzed for pH, EC, and ionic concentrations were evaluated by using neutralization factor analysis, factor analysis, and trajectory analysis. The results revealed that Na⁺ was derived mainly from crustal sources. However, K⁺, Mg²⁺, and Ca²⁺ were only mainly controlled by crustal sources, with contribution rates of 93.60%, 58.88%, and 98.10%, respectively. Marine sources made the greatest contribution to Cl⁻ (99.03%). The most important contributor of NO3⁻ (99.52%) and SO4²⁻ (83.23%) was anthropogenic sources. F⁻ was mainly controlled by crustal sources and anthropogenic sources. Although there were different water vapor paths in different seasons at different sample sites, water vapor in the study area was mainly controlled by westerly circulation and monsoon circulation. The largest contributions of westerly circulation were for Cl⁻ and K⁺, whereas monsoon circulation mainly contributed the ionic concentration of NH4⁺. However, the largest number of ions was contributed by a westerly circulation–monsoon circulation pattern. These ions were F⁻, NO2⁻, SO4²⁻, Li⁺, Na⁺, Mg²⁺, and Ca²⁺, with contributions of 51.20%, 41.60%, 42.30%, 53.68%, 40.36%, 40.22%, and 34.20% of the total, respectively. NO3⁻ was mainly contributed by westerly circulation–regional circulation.
Aerosol particle number (PNC) and mass concentrations (PMC) were studied in 11 primary schools during the 2017–2018 school years (from September to May) in Vilnius, Lithuania, with the aim to evaluate the main aerosol pollution sources and its levels. Expeditious information on the total aerosol particle concentration over the full range of sizes (from 0.01 to > 1 μm) was estimated using a condensation particle counter (CPC). Particle number and mass concentrations in the size range of 0.3–10 μm were measured and estimated using an optical particle sizer (OPS). The use of aerosol particle size spectra (OPS) in school lodgements facilitated the identification of the main sources of indoor air pollution. The main sources responsible for the elevated levels of indoor PN and PM aerosol concentrations were determined: local canteens in the absence of ventilation (particle concentrations up to 97,500 part/cm³ (CPC)), the school-grader activity during the lesson breaks (275–586 μg/m³), soft furniture and carpets in the classrooms and corridors (~ 200 μg/m³), and in some cases (city center) elevated outdoor aerosol pollution levels (16800–18,170 part/cm³). Elevated aerosol pollution levels were also due to the occasional sources: construction works during lessons (200–1000 μg/m³), scraping the exterior walls of buildings near schools (up to 1600 μg/m³), and the use of petrol-powered trimmers during cutting of green plantings (22500–66,400 part/cm³ (CPC)).
This study presents the spatial interpolation procedure from snow depth measurements at weather stations implying the following stages: (1) Spatial interpolation at 1 km × 1 km resolution of the mean multiannual values (2005-2015) corresponding to each month, computed from the data extracted from the climatological database; (2) Computation of the daily deviations against the multiannual monthly mean for every day and year over 2005-2015 and their spatial interpolation; (3) Spatio-temporal datasets were obtained through merging the two surfaces obtained in stages 1 and 2. The anomalies were considered to be the ratio between the daily snow depth values and the climatology. The spatial variability of the data used in the first stage was accounted for through the use of a series of predictors derived from the digital elevation model (DEM). To plot the maps with the climatological normals (multiannual means), the Regression-Kriging (RK) spatial interpolation method was used. In order to choose the optimum method applied in spatializing deviations, four interpolation methods were tested using a cross-validation procedure: Multiquadratic, Ordinary Kriging (separated and pooled variograms) and 3d Kriging.
A study of precipitation chemistry was conducted for 11 years (01 January 2006 - 31
December 2016) in the Ciuc basin, Eastern Carpathians, Romania. The studied area is
an enclosed basin, also called 'the Carpathians cold pole'. All collected samples were
analyzed for major cations and anions. HCO3− concentrations were calculated based
on the empirical relationship between pH and HCO3-. The multiannual arithmetic mean
of pH values was found to be 6.57. The lowest and highest pH values were measured
in 2009 and 2013, being 6.57% lower, respectively 7.57% higher than the multiannual
mean. Only 3.31% of the studied rainwater samples indicate acidic character. In
descending order, the majority of the samples are as follows: NH4+ >Ca2+ >SO42− >Cl−
>HCO3− >NO3− >Na+ >K+ >Mg2+ >NO2− >H+. Principal Component Analysis (PCA),
showed the NH4+, Ca2+ and Mg2+ contribution to the neutralization process and their
sources. The anthropogenic origin of SO42− was supported by the high non-sea salt
fraction (NSSF) (~91%). The results of this study suggest that rainwater chemistry is
strongly influenced by local natural and anthropogenic sources (agricultural activities)
rather than marine sources. The pollutants in rainwater samples were mainly derived
from calcareous and dolomitic soil dust and specific local climatic conditions, longrange
transport, local industry and traffic sources.
The pollutants emitted into the atmosphere may be transformed after certain time; they can come out from the atmosphere as dry or wet deposition. The plant species characteristic to the Ciuc basin is the pine, forming large forests that constitute the primary surface deposition. According to that, dry deposition calculations have been carried out, based on the pine forests. Regarding the deposition changes, PM10 and PM2.5 do not differ, but their effects on the health are very different. This results especially from their dimension and concentration. Their deleterious effect on the human health in the Ciuc basin was examined through the relative risk factor. The results showed that people are more disposed to cardiovascular diseases, lung cancer, acute and chronic respiratory diseases, asthma and other diseases. In addition, regarding the microclimate formation (atmospheric stability) in the Ciuc basin, the atmospheric pollution does not concern only the city of Miercurea Ciuc. The calculated risk factors are applied to the entire population within the basin.
Major ions, pH and electric conductivity (EC) in rainwater samples collected from June 2011 to July 2012 were analyzed to evaluate chemical characteristics and source apportionment of rainwater in Xi’an, a city located on the loess deposits. The rainwater was slightly alkaline with a daily volume-weighted mean (VWM) pH of 7.7, which ranged from 7.4 to 8.4. The VWM concentrations of major ions followed the order of Ca2+ > SO42− > NH4+ > NO3− > Cl− > Na+ > K+ > Mg2+ > F−. Ca2+ and SO42− dominated in cations and anions, respectively. Investigations of neutralization factors indicated that the acidity of rainwater in Xi’an was neutralized by NH4+ and Ca2+, which presented relatively higher neutralization capability than cities in southern China. The back trajectory analysis showed that the chemistry of rainwater in Xi’an is influenced by local pollutions sources and soil dust in local and remote area. Large inputs of soil dust and coal combustion during the winter and spring led to higher values of major ions and pH values during dry seasons than wet seasons. The principal factor analysis, correlation analysis, and source apportionment indicated that SO42− and NO3− were from anthropogenic sources, while Ca2+, K+, and Mg2+ were from crust fractions. The estimated annual wet depositions for sulfur, nitrogen, and calcium were 3.9, 1.5, and 4.2 t/km2, respectively. Although rainwater acidity in Xi’an was mainly caused by H2SO4, the contribution of HNO3 will be enhanced due to increasing NOx and relatively stable SO2 emissions in the future. The high concentrations of EC, SO42−, and NO3− in rainwater indicated Xi’an is severely polluted. To improve air quality in Xi’an, simultaneous reduction of particle emissions and fossil fuel and vehicles emissions are worthy of advocating. The results have implications for identification of potential sources in rainwater and for evaluation of air quality improvement in Xi’an and other similar cities in China.
The chemistry of rainwater was studied in three sites of a metropolitan city of Turkey to determine the spatial variation, sources affecting composition and the extent of their influence. The acidity of rainwater, Ca, Co, Cr, Zn, Ba, V and Ni showed significant spatial variations. The most of measured species were moderately to extremely enriched compared to the local soil, which is likely arisen from the anthropogenic activities. SO42−, K and Ca were found to be predominantly non-sea origin. Two receptor models, Positive Matrix Factorization (PMF) and Chemical Mass Balance (CMB), agreed well on the source contribution estimations of Al, K, Zn, V, Pb and Cr. The PMF and CMB resolved very similar source contribution profiles to the elemental concentrations of Ca, Zn, V, Pb, K and Na, which the majority of those resulted from mineral industries, bell casting+steel industries, fossil fuel burning, biomass burning+sea salt and sea salt, respectively. The PMF resolved the source contributions of long-transported emissions, particularly for Ba, Sr and Mn, which could not be estimated by the CMB.
The gas-phase ammonia (NH3) and fine particle PM2.5 ammonium (pNH4 (+)) (collectively, NHx) were monitored between July 2013 and August 2014 in a busy traffic area of Nanjing, China. Results showed that PM2.5 concentration was 66.7 μg m(-3), and NH3 concentration was 6.66 μg m(-3). In the PM2.5, the concentration of pNH4 (+) was 3.04 μg m(-3), SO4 (2-) (pSO4 (2-)) was 10.16 μg m(-3), and NO3 (-) (pNO3 (-)) was 1.60 μg m(-3). The significant correlation curves from the tests of PM2.5 revealed that molar ratio of pNH4 (+) and pSO4 (2-) was approximately 2, which could be (NH4)2SO4. Particulate NH4 (+) primarily associated with pSO4 (2-), which accounted for 4.54 % of total PM2.5 mass. The PM2.5 observed acidic and the NH3 in the atmosphere neutralized acidic species, mainly in a sulfate form. The traffic intensity in the region was partially related to the formation of PM2.5 and NH3, suggesting that traffic pollution may be an important source of PM2.5. The reaction between NHx and acidic species was assumed to the secondary PM2.5. The neutralization and photochemical property of NHx were discussed.
Prior to mining, the water in and around the mine is rarely influenced by human activities, and hydrogeochemical processes are the major factors influencing and controlling water chemistry. To identify these natural hydrogeochemical processes in Laoheba phosphorite mine (Sichuan Province, China), correlation and multivariate statistical techniques were used. Results show that water quality in the area is generally good before the Laoheba phosphorite mine goes into construction and production. The cluster analysis classified water samples into 4 clusters (C1-C4). Samples from C1 and C2 are of HCO3-Ca center dot Mg and HCO3-Ca type, while those from C3 and C4 are of HCO3-Ca center dot Mg type. Most parameters except Cl- and pH show an increasing trend in the order of C1 to C4. Three principal components were extracted, and PC1 represents the ion exchange and the weathering of calcite, dolomite, and silicate minerals. PC2 and PC3 indicate the process of water recharge from upstream waters and the process of evaporation, respectively. The hydrochemistry of waters in the area is a result of multiple factors, and natural mineral weathering and ion exchange are the most important ones.
A total of 50 rainwater samples were analyzed in order to investigate trace elements in wet precipitation of Juiz de Fora City, during February, 2010 and February, 2011. Samples were analyzed for major cations (H3O+, Na+, NH4+, K+, Mg-2(+) and Ca-2(+)) and anions (NO3-, SO42-, Cl-and HCO3-), hydrogen peroxide (H2O2), some trace metals (Cu-2(+), Zn-2(+), Cd-2(+) and Pb-2(+)), as well as some other physicochemical aspects like pH, conductivity and redox potential. Rainwater pH mean was of 5.77 (+/- 0.52). Cations and anions mean values ranged from 7.12 mu Eq L-1 (K+) to 39.6 mu Eq L-1 (Ca2+). Principal Component Analysis (PCA) with Varimax normalized rotation was performed, grouping the major analyzed cations and anions into different factors. Mg2+, K+, Ca2+ and HCO3-were assigned to soil contribution, Na+ and Cl-to sea-salt contribution and NO3-, SO42-and NH4+ to anthropogenic sources. Hydrogen peroxide average concentration was of 19.2 +/- 17.5 mu mol L-1 with higher values in summer and lower in spring and autumn, reverse case was observed for H3O+ levels. Zn2+ (7.31 +/- 2.74) mu g L-1 and Cu2+ (4.07 +/- 0.74) mu g L-1 were within the range of other studied areas, while Cd2+ and Pb2+ were below the detection limit.
To improve the air quality during the 2008 Beijing Olympic Games, the Beijing Municipal Government enforced a series of emission control measures. This provided a valuable case study to evaluate the effectiveness of these aggressive measures on mitigating air pollution and improving the atmospheric environment. In this paper, we report the first results of the chemical and Sr isotopic compositions of the rainwater in Beijing during the 2008 Olympic year. The ionic composition of samples show that Ca2 + and NH4+ were the dominant cations, accounting for about 76–97% of the total cations, and that SO42 − and NO3− were the major anions, accounting for 61–91% of the total anions measured. Using Na as the indicator of marine origin and Al as that of terrestrial inputs, the proportions of sea salt and terrestrial elements were estimated from elemental ratios. The calculated results indicate that the major chemical components were mainly of non-sea-salt origin. Good correlation between Ca2 + and Sr2 + (R2 = 0.85) in rainwater samples indicates the potential of Sr as a provenance tracer for Ca. Sr2 + concentrations in rainwater samples ranged from 0.01 to 2.87 μmol l− 1, with 87Sr/86Sr ratios from 0.7092 to 0.7109. All of the samples had a 87Sr/86Sr ratio higher than that of seawater. The 87Sr/86Sr isotopic and elemental ratio systems show that the data set of rainwater was mainly distributed between the seawater end-member (~ 0.70917) and the soil dust end-member (0.7111–0.7115), and the analysis indicate that the effect of anthropogenic inputs could decrease in 2008. Comparisons of the chemical composition of the rainwater in different periods show that all chemical components, except NH4+, had the lowest concentration levels during the Olympic Game period. The VWM concentrations of major ions in the rainwater decreased significantly during the Olympic period by up to 29% for SO42 −, 39% for NO3−, 38% for Ca2 +, 51% for Mg2 +, 57% for K+, and 44% for Na+, compared with the pre-control period. The concentrations of almost all species decreased during the 2008 Olympics, most likely due to both strict emission controls and favorable meteorological conditions.
Gaseous ammonia (NH3) is the most abundant alkaline gas in the atmosphere. In addition, it is a major component of total reactive nitrogen. The largest source of NH3 emissions is agriculture, including animal husbandry and NH3-based fertilizer applications. Other sources of NH3 include industrial processes, vehicular emissions and volatilization from soils and oceans. Recent studies have indicated that NH3 emissions have been increasing over the last few decades on a global scale. This is a concern because NH3 plays a significant role in the formation of atmospheric particulate matter, visibility degradation and atmospheric deposition of nitrogen to sensitive ecosystems. Thus, the increase in NH3 emissions negatively influences environmental and public health as well as climate change. For these reasons, it is important to have a clear understanding of the sources, deposition and atmospheric behaviour of NH3. Over the last two decades, a number of research papers have addressed pertinent issues related to NH3 emissions into the atmosphere at global, regional and local scales. This review article integrates the knowledge available on atmospheric NH3 from the literature in a systematic manner, describes the environmental implications of unabated NH3 emissions and provides a scientific basis for developing effective control strategies for NH3.
A comprehensive study on the chemical compositions of rainwater was carried out from Jan. to Dec. in 2008 in Chengdu, a city located on the acid rain control zone of southwest China. All samples were analyzed for pH and major ions (F–, Cl−, NO3−, SO42−, K+, Na+, Ca2+, Mg2+, and NH4+). The pH increased due to the result of neutralization caused by the base ions. It was observed that Ca2+ was the most abundant cation with a VWM value of 196.6 μeq/L (17.3–1568.7 μeq/L), accounting for 49.7% (9.4%–79.2%) of the total cations. SO42− was the most abundant anion with VWM value of 212.8 μeq/L (41.8–1227.6 μeq/L). SO42− and NO3− were dominant among the anions, accounting for 90.4%–99.1% of the total measured anions.The concentrations of NO3− were higher than the most polluted cities abroad, which indicated Chengdu has been a severe polluted city over the world. The high fuel consumption from urbanization and the rapid increase of vehicles resulted in the high emission of SO2 and NOx, which were the precursor of the high concentration of acidic ions NO3− and SO42−. It was the main reason of the severe acid rain in Chengdu.The high concentrations of alkaline ions (mainly Ca2+, NH4+) in Chengdu city atmosphere have played an important role to neutralize the acidity of rainwater and the pH value has increased by 0.7 units since 1989. It is worth noting that the emission of NOx from the automobile exhaust is increased and is becoming the important precursor of acid rain now.Research Highlights► The chemical compositions in a series of acid rainwater. ► SO2 and NOX emission from automobile exhaust are increasing. ► Calcium-rich dust masked the acid rain.
ERA-Interim is the latest global atmospheric reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). The ERA-Interim project was conducted in part to prepare for a new atmospheric reanalysis to replace ERA-40, which will extend back to the early part of the twentieth century. This article describes the forecast model, data assimilation method, and input datasets used to produce ERA-Interim, and discusses the performance of the system. Special emphasis is placed on various difficulties encountered in the production of ERA-40, including the representation of the hydrological cycle, the quality of the stratospheric circulation, and the consistency in time of the reanalysed fields. We provide evidence for substantial improvements in each of these aspects. We also identify areas where further work is needed and describe opportunities and objectives for future reanalysis projects at ECMWF.
The distribution of acidic andalkaline constituents (SO4
2-,NO3
-, Cl-, NH4
+, Na+,K+, Ca2+) between the fine and coarseparticle range has been examined in an urban locationin Thessaloniki, N. Greece over an 8-month period. The chemistry of wet and dry deposition collected overthe same period was also examined. Statisticalassociations between species within each environmentalphase were investigated using correlation analysis.Use of principal component analysis was made toinvestigate compositional similarities betweenaerosol, deposited dust and rain. It was found thatSO4 followed by NO3, NH4 and Caprevailed in fine aerosol. Sulphates and Ca were alsothe prevailing ions in the coarse particle fraction.Wet deposition was found to be the dominant depositionmechanism for all species. The high dry depositionrates observed for Ca and SO4 suggest that mostof the dry deposited sulphate is in the form ofCaSO4. Scavenging ratios of ionic speciesassociated with coarse aerosol were higher than thecorresponding ratios for fine particles. Principalcomponent analysis suggested that variations in ioniccomposition of fine aerosol could be interpretedprimarily by gas-to-particle neutralization reactionsinvolving atmospheric ammonia. In contrast, theinteraction between SO2 and HNO3 with Cacompounds seems to be the most likely factor that canexplain variations in wet and dry deposition ioniccontents.
Rainwater samples were collected for the monsoon period of 1988 and 1991–1996 at Dayalbagh (Agra), a suburban site situated in semiaridregion. The mean pH was 7.01 1.03 well above 5.6, which is the reference pH. Concentration of Ca2+ was observed to be highest followed by Mg2+, NH4
+,SO4
2–, Cl–,NO3
–, Na+, F– and K+. The ratios of SO4
2– + NO3
– andCa2+ + Mg2+ (TA/TC) have been considered as indicatorfor acidity. In the Agra region ratio of TA/TC is quite below 1.0 indicating alkaline nature of rainwater. The lowest value of 0.24 was observed in 1991 likely due to the lowest rain depth of the decade. The highest value of 0.54 was observed in 1996, a year with a large rain depth and increase in line (vehicular traffic) and area sources (population growth). Good correlation between Ca2+ and NO3
–,Ca2+ and SO4
2– andSO4
2– and NO3
–,indicates that wind carried dust and soil play a significant role in neutralization of precipitation acidity.
The results of chemical analysis of precipitation samples collected in Petra between October 2002 and May 2004 are presented. All samples were analyzed for major cations (NH4+, Na+, K+, Ca2+ and Mg2+), major anions (Cl−, NO3−, HCO3− and SO42−), conductivity and pH.The daily sample pH values ranged from 5.71 to 8.15 with an average value of 6.85 ± 0.5. Rainwater quality is characterized by low salinity and neutralized pH. Generally, the pH is high due to dust in the atmosphere, which contains a large fraction of calcite. Factor analysis was used to identify the factors that affect the presence of ions in wet precipitation; these factors permitted the identification of three source groups, namely crustal dust, sea-salt spray and combustion products.In general, the results of the present study suggest that the atmospheric composition in the Petra region is strongly influenced by natural sources rather than anthropogenic sources.
Atmospheric ammonia plays an important role in haze formation in East China. In this study, long-term measurements of NH3 concentrations were implemented at urban, suburban, and tunnel sites in Shanghai, the largest city in East China. The average monthly ammonia concentrations at the urban site varied from 3.7 ppb to 14.5 ppb and exhibited the highest levels in summer and lowest levels in winter, indicating that the biological emissions and agriculture in the surrounding areas are important contributors. The suburban NH3 levels were significantly higher in autumn compared to those at the urban site, indicating the important contribution of agricultural activities. Regardless of the season, the difference of NH3 concentrations between the tunnel and urban sites remained almost constant. On average, the tunnel NH3 level was three times higher than that of the nearby urban site, indicating strong vehicle NH3 emissions in the tunnel. The tunnel NH3 levels on weekdays were comparable to those on weekends, a result that was in agreement with the daily average traffic volume. It was estimated that the vehicle emissions contributed 12.6–24.6% of the atmospheric NH3 in the urban area and 3.8–7.5% for the whole area of Shanghai. Our results suggest that vehicle NH3 emissions should be considered, although agricultural emissions are still more important for mitigating severe haze pollution during wintertime in the megacities of China.
Long-term monitoring of precipitation chemistry provides a great opportunity to examine the evolution of air pollutant emissions and effectiveness of air pollution control measures. We evaluated the characteristics and trends of precipitation chemistry at both annual and seasonal scales based on the records of 1994‒2013 at Fushan Experimental Forest (FEF) of northeastern Taiwan. The results showed that 77% of the weekly precipitation had pH < 5.0. The two-decadal average annual pH was 4.62, without a significant inter-annual trend, possibly due to the concurrent declines of both acidic pollutants and base cations. There was a significant positive relationship between [SO42- + NO3-] and [Ca2+ + NH4+] indicating that their deposition was likely dominated by NH4NO3, (NH4)2SO¬4, Ca(NO3)2, and CaSO4. There was a significant negative relationship between precipitation pH and the difference between [SO42- + NO3-] and [Ca2+ + NH4+], not just [SO42- + NO3-], suggesting that precipitation acidity was not solely determined by acidic pollutants but by the balance between acidic pollutants and base cations. We also found temporal decreases of Ca2+ and NH4+ concentrations in precipitation which contributed to the low acid neutralization capacity of precipitation. Annual deposition of NO3- and SO42- was 23 and 55 kg ha-1 yr-1, which is much higher than most forest sites in the industrialized countries suggesting that acid deposition is still a major environmental issue in Taiwan. Annual deposition of NH4+, Ca2+ and NO3- showed significant decreasing trends during the 20-year period, which was mostly due to the decreases in the summer deposition associated with air pollution mitigation strategies. Winter deposition showed no decreasing patterns for the same period. The high contribution to annual acid deposition from autumn-winter and spring rains (50%) associated with northeast monsoon implies that long-range transport of anthropogenic emissions from East Asia played a key role on acid depositions at FEF and possibly many areas in the region. Therefore, intergovernmental cooperation are urgently needed to effectively mitigate the threat of acid deposition in East Asia.
The major ions and Sr isotopes in rainwater have been studied during 2013–2015 on the Alxa Desert Plateau in order to identify the source of rainwater chemistry and to assess air quality in the desert area of northern China. The pH and EC values of rainwater vary from 6.7 to 8.1 and from 35 to 1237 μS cm− 1, respectively, at the two meteorological stations (AYQ and YBL) in the Alxa Desert Plateau. Ca2 +, SO42 −, Na⁺ and Cl⁻ are the dominant ions in rainwater, possessing > 85% of total ions. The mean daily wet deposition fluxes of soluble ions are 8709 μeq/m²/d at YBL and 5459 μeq/m²/d at AYQ, approaching the values at Xi'an, Beijing, Guangzhou, and Chengdu. Statistical analysis shows that SO42 − and NO3⁻ in rainwater were mainly from anthropogenic sources while Ca2 + and K⁺ originated from terrestrial sources. Cl⁻ was mainly from seawater sources, and Na⁺ was partly from mineral weathering. Major ions are well correlated with each other in rainwater, revealing that substances of various origins were synchronously carried into the atmosphere by wind. By using Sr isotope techniques, three main end-members controlling base cations of rainwater are identified: silicates, carbonates and seawater. Based on the analyses of acid-soluble fractions of desert soils, local soil dust could be the most important source of base cations in rainwater whereas the effect of the anthropogenic sources could be neglected.
Understanding the trend of chemical composition of precipitation is of great importance for air pollution control strategies in Northern China. A comprehensive study on the long-term chemical compositions of precipitation was carried out from 2003 to 2014 at the Shangdianzi (SDZ) regional background station in northern China. All samples were analyzed for pH, electrical conductivity and major ions (F⁻, Cl⁻, NO3⁻, SO42 −, NH4⁺, Mg2 +, Ca2 +, K⁺ and Na⁺). The average pH during this period was 4.53 ± 0.35, which is considerably lower than those reported in other background stations in China (Linan, Waliguan and Longfengshan). NH4⁺, SO42 −, Ca2 + and NO3⁻ were the dominant ions in precipitation, with concentrations (volume-weighted mean) of 212.99 μeq L− 1, 200.20 μeq L− 1, 116.88 μeq L− 1 and 98.56 μeq L− 1, respectively. The ion concentrations at SDZ were much higher than those of other background stations and megacities in China. A significantly increasing trend was observed for NO3⁻ (7.26% year− 1), and a decreasing trend was observed for SO42 −/NO3⁻, suggesting that the precipitation of SDZ evolved from a sulfuric acid type to a mixed type dominated by both sulfuric and nitric acid. The source identification indicated that SO42 −, NO3⁻, NH4⁺ and F⁻ were dominated by secondary sources, Mg2 +, Ca2 + and Na⁺ mostly originated from natural sources, and K⁺ and Cl⁻ probably associated with anthropogenic sources. Long-range transport of air masses could influence the acidity, electrical conductivity and ion concentrations of precipitation at SDZ. The higher acidity and ion concentrations mainly occurred in the southerly and westerly trajectory pathways and partially in northwest pathways. Anthropogenic pollutants and crustal sources along these pathways were significant contributors to the chemical composition of precipitation in SDZ.
The Caohai Wetland, Guizhou Province, China, is a nationally important nature reserve. In this study, we examined the major ion composition of the inflows to, and the water in, the Caohai Wetland. The main sources of major ions in the wetland water were the groundwater and river water inflows, the chemical compositions of which were controlled by the local geology, aquifer water?rock interactions, and human activities. The inflowing waters were the Ca?HCO3 type. The wetland water was classified as the Mg-HCO3, Mg-SO4, Ca-HCO3, and Ca-SO4 types during the high-flow season, and as the Ca-HCO3 type in the low-flow season. The physical and chemical properties of the wetland water varied widely from west to east. Concentrations of K+, Ca+, Mg2+, Cl?, and HCO3? in the wetland water were higher in the low-flow season than in the high-flow season; K+, Na+, Cl?, and Mg2+ concentrations were higher in the wetland than in the inflowing waters in both seasons, and HCO3? concentrations were lower in the wetland than in the inflowing waters. The chemical composition of the wetland water was mainly controlled by biogeochemical processes and evaporation in the high-flow season, and by evaporation in the low-flow season.
South Africa is the economic hub of southern Africa and is regarded as an important source region of atmospheric pollutants. A nitrogen dioxide (NO2) hotspot is clearly visible from space over the South African Mpumalanga Highveld, while South Africa is also regarded as the 9th largest anthropogenic sulphur (S) emitting country. Notwithstanding the importance of South Africa with regard to nitrogen (N) and S emissions, very limited data has been published on the chemical composition of wet deposition for this region. This paper presents the concentrations of sodium (Na+), ammonium (NH4+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), nitrate (NO3−), chloride (Cl−), sulphate (SO42−) and water-soluble organic acids (OA) i