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(Top left): The average (2003-2020) HCHO concentration in MAM (March, April and May) over India with major cities and ports marked in circles. Top right. The Trends in HCHO observed in the annual averaged data over India. The statistically insignificant trends are hatched. Bottom: The trends computed for annual averaged data and for the seasons: December-February (DJF), March-May (MAM), June-August (JJA) and September-November (SON) at specific regions, cities and Ports during the study period 2003-2020. The ports, cities and regions are shown in Figs. S1 and S2.
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Atmospheric formaldehyde (HCHO) has significant adverse health effects at higher concentrations. It is an unstable and inflammable organic compound, and is an index for atmospheric pollution. Although the ambient HCHO is due to methane oxidation, the localised enhancement in HCHO is mostly from the emissions of non-methane volatile organic compound...
Citations
... Bi-hierarchical balanced incomplete block (BiHBIB) designs more popularly known as nested balanced incomplete block (NBIB) designs, eliminate two sources of hierarchical variation present in the experimental material. Several researchers addressed the problem of finding optimal ME design using NBIB designs, group divisible designs, circular designs, etc. [12][13][14][15] . ...
... We observed a significant surge in CO and HCHO concentration over northern parts of Uttar Pradesh and Bihar during April 2024 caused by forest fires in Uttarakhand and subsequent transport by prevailing wind conditions. Although HCHO has a short atmospheric lifetime varying from several minutes to a few hours 12 , it can still be detected from a satellite due to prolonged emissions from fire events and wind-driven transport. ...
Forest fires in the Western Himalaya region pose significant environmental and health challenges. The present communication examines the impact of these fires on air quality, focusing on elevated levels of carbon monoxide, formaldehyde and aerosols. Utilizing satellite inputs and chemistry transport models such as Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT), the study traces pollutant dispersion and concentration. The findings highlight high concentration and extended lifetime of trace gases, with implications for public health and long-term environmental effects.
... Figure 4 shows the global maps of HCHO total column trends derived from OMI, the prior M2GMI, and the posterior M2GMI. The widespread upward trends in HCHO over India are evident due to a lack of effective efforts to cut emissions related to VOCs (e.g., De Kuttippurath et al., 2022;Bauwens et al., 2022). We observe HCHO columns going up in the northwestern US and over oil sands in Canada, possibly due to increased evergreen needleleaf forests and an increase in crude oil production , respectively. ...
The tropospheric hydroxyl (TOH) radical is a key player in regulating oxidation of various compounds in Earth's atmosphere. Despite its pivotal role, the spatiotemporal distributions of OH are poorly constrained. Past modeling studies suggest that the main drivers of OH, including NO2, tropospheric ozone (TO3), and H2O(v), have increased TOH globally. However, these findings often offer a global average and may not include more recent changes in diverse compounds emitted on various spatiotemporal scales. Here, we aim to deepen our understanding of global TOH trends for more recent years (2005–2019) at 1×1°. To achieve this, we use satellite observations of HCHO and NO2 to constrain simulated TOH using a technique based on a Bayesian data fusion method, alongside a machine learning module named the Efficient CH4-CO-OH (ECCOH) configuration, which is integrated into NASA's Goddard Earth Observing System (GEOS) global model. This innovative module helps efficiently predict the convoluted response of TOH to its drivers and proxies in a statistical way. Aura Ozone Monitoring Instrument (OMI) NO2 observations suggest that the simulation has high biases for biomass burning activities in Africa and eastern Europe, resulting in a regional overestimation of up to 20 % in TOH. OMI HCHO primarily impacts the oceans, where TOH linearly correlates with this proxy. Five key parameters, i.e., TO3, H2O(v), NO2, HCHO, and stratospheric ozone, can collectively explain 65 % of the variance in TOH trends. The overall trend of TOH influenced by NO2 remains positive, but it varies greatly because of the differences in the signs of anthropogenic emissions. Over the oceans, TOH trends are primarily positive in the Northern Hemisphere, resulting from the upward trends in HCHO, TO3, and H2O(v). Using the present framework, we can tap the power of satellites to quickly gain a deeper understanding of simulated TOH trends and biases.
... The Indo-Gangetic Plain (IGP) stretches from Eastern Pakistan to Bangladesh and is a major agricultural region in India (Kuttippurath et al., 2022). Thus, averaging the HCHO columns over a diverse landscape can lead to less-prominent seasonality. ...
... The observed and modeled amplitudes of the HCHO seasonal cycle are 40 %. Both datasets show enhanced HCHO levels during spring, consistent with high isoprene concentrations (Fig. S4) Biogenic emissions are the main driver of the HCHO levels in east India; however, emissions from mines are also potential sources of NO x and VOCs (Kuttippurath et al., 2022). ...
Formaldehyde (HCHO), a precursor to tropospheric ozone, is an important tracer of volatile organic compounds (VOCs) in the atmosphere. Two years (2019–2020) of HCHO simulations obtained from the global chemistry transport model CHASER at a horizontal resolution of 2.8° × 2.8° have been evaluated using the Tropospheric Monitoring Instrument (TROPOMI) and multi-axis differential optical absorption spectroscopy (MAX-DOAS) observations. In situ measurements from the Atmospheric Tomography Mission (ATom) in 2018 were used to evaluate the HCHO simulations for 2018. CHASER reproduced the TROPOMI-observed global HCHO spatial distribution with a spatial correlation (r) of 0.93 and a negative bias of 7 %. The model showed a good capability to reproduce the observed magnitude of the HCHO seasonality in different regions, including the background conditions. The discrepancies between the model and satellite in the Asian regions were related mainly to the underestimated and missing anthropogenic emission inventories. The maximum difference between two HCHO simulations based on two different nitrogen oxide (NOx) emission inventories was 20 %. TROPOMI's finer spatial resolution than that of the Ozone Monitoring Instrument (OMI) sensor reduced the global model–satellite root-mean-square error (RMSE) by 20 %. The OMI- and TROPOMI-observed seasonal variations in HCHO abundances were consistent. The simulated seasonality showed better agreement with TROPOMI in most regions. The simulated HCHO and isoprene profiles correlated strongly (R=0.81) with the ATom observations. However, CHASER overestimated HCHO mixing ratios over dense vegetation areas in South America and the remote Pacific region (background condition), mainly within the planetary boundary layer (< 2 km). The simulated seasonal variations in the HCHO columns showed good agreement (R>0.70) with the MAX-DOAS observations and agreed within the 1σ standard deviation of the observed values. However, the temporal correlation (R∼0.40) was moderate on a daily scale. CHASER underestimated the HCHO levels at all sites, and the peak occurrences in the observed and simulated HCHO seasonality differed. The coarseness of the model's resolution could potentially lead to such discrepancies. Sensitivity studies showed that anthropogenic emissions were the highest contributor (up to ∼ 35 %) to the wintertime regional HCHO levels.
... 89 HCHO has adverse health effects at higher concentration from direct exposure, and due to its catalytic effects in the formation of atmospheric sulphate, which is a key component of particulate matter (PM). 90,91 HCOOH is an organic acid present in the atmosphere, which has an impact on the precipitation chemistry and acidity of the rain water. [92][93][94] It is also a greenhouse gas which affects the radiative balance of the atmosphere by the direct absorption of the solar radiation or by the scattering of radiation by generated secondary organic aerosol (SOA). ...
The reactions of the simplest Criegee intermediate (CH2OO) with n-butyraldehyde (nBD) and isobutyraldehyde (iBD) were studied at 253–318 K and (50 ± 2) torr, using Cavity Ring-down spectroscopy (CRDS). The rate coefficients obtained at room temperature were (2.63 ± 0.14) × 10−12 and (2.20 ± 0.21) × 10−12 cm3 molecule−1 s−1 for nBD and iBD, respectively. Both the reactions show negative temperature-dependency, following equations, knBD(T = 253–318 K) = (11.51 ± 4.33) × 10−14 × exp{(918.1 ± 107.2)/T} and kiBD(T = 253–318 K) = (6.23 ± 2.29) × 10−14 × exp{(1051.4 ± 105.2)/T} cm3 molecule−1 s−1. High-pressure limit rate coefficients were determined from theoretical calculations at the CCSD(T)-F12/cc-pVTZ-F12//B3LYP/6-311+G(2df, 2p) level of theory, with <40% deviation from the experimental results at room temperature and above. The kinetic simulations were performed using a master equation solver to predict the temperature-dependency of the rate coefficients at the experimental pressure, as well as to predict the contribution of individual pathways. The major products predicted from the theoretical calculations were formaldehyde and formic acid, along with butyric acid from nBD and isobutyric acid from iBD reactions.
... As per the IHME evalutions, it was linked to 365,000 premature deaths worldwide due to chronic obstructive pulmonary disease (COPD) in 2016 alone and has been increasing from 2014 onwards (Izadi, 2018). The formation of ozone near the surface is driven by a number of complex reactions of precursors with transport on all scales (Travis et al., 2016;Joshi et al., 2023;Kuttippurath et al., 2022). As each city has its unique pollution sources and challenges, tailored interventions are devised globally to address local air pollution issues effectively (Han et al., 2022;Chen et al., 2021;Liu et al., 2022). ...
... HCHO is considered a proxy for VOCs, as it is produced directly by the oxidation of VOCs (Gopikrishnan & Kuttippurath, 2021). Kuttippurath et al. (2022) investigated the sources and long-term trends in HCHO using different satellite measurements and reported positive trends of 0.3-0.5×10 15 molec cm − 2 yr − 1 in India during the period 2005-2020. ...
There is a significant increase in ozone at the surface and troposphere due to growing population, industrialization and urbanization. The initiation of National Clean Air Programme (NCAP) in 2019 marked a turning point in addressing air pollution in Indian cities. The Central Pollution Control Board (CPCB) ground-based measurements show a reduction in number of days with continuous exposure to 8 h surface ozone (MDA-8) exceeding 100 ppb since the implementation of NCAP. For instance, cities such as Visakhapatnam and Tirupati reported zero days of MDA-8 ozone surpassing 100 ppb in 2022. Also, a substantial reduction is observed in the frequency of MDA-8 ozone exceeding the 100 ppb threshold at other stations. The NO2 and PM2.5 measurements from CPCB show a decreasing trend at most stations, whereas satellite-based HCHO and NO2 measurements show negative (0–0.004 mol m−2 month−1) and positive (0–0.02 m−2 month−1) trends, respectively, during the period of 2019–2022. Therefore, although the implementation of NCAP is oriented towards reducing PM10 concentrations, it is also proven to be effective in curbing ozone pollution in most cities of India. This study, therefore, suggests to continue the efforts of NCAP and to implement tailored regulations for reducing ozone pollution in cities with high pollution.
... Kuttippurath et al believed that HCHO was of great harm to human body. They used remote sensing satellite to measure HCHO column concentration in India and found that in the lockdown period of COVID-19, the increase of HCHO concentration in atmosphere was related to pyrogen and biological sources besides anthropogenic sources [5]. Bai et al estimated the emission fluxes of isoprene and BVOCs in subtropical plantation based on HCHO data measured by satellites and the quantitative relationship between BVOCs-HCHO [6]. ...
In recent years, with the acceleration of industrialization and the expansion of urban scale, air pollution including formaldehyde (HCHO) becomes more and more serious. In order to study HCHO pollution in the Yangtze River Economic Belt (YEB), the temporal and spatial evolution of atmospheric HCHO and its influencing factors were analyzed by using the Ozone Monitoring Instrument (OMI) during 2012-2021. The results showed that the concentration of YEB HCHO column was unevenly distributed, with high values concentrated in Anhui, Jiangsu, Yunnan and Hubei provinces. During the past 10 years, the concentration of YEB HCHO column varied between 10.28 and 17.19×1015molec/cm2, and the lowest concentration of HCHO column was 13.16×1015molec/cm2 in 2015. However, it reached the peak value in 2018 (14.93×1015molec/cm2). In natural sources, normalized vegetation index (NDVI) and leaf area index (LAI) had greater influence on YEB HCHO, and the correlation was -0.91~0.97 and -0.9~0.95, respectively. The positive correlation area between HCHO and Mean annual temperature (MAT) reached 93%. The contribution of high-intensity human activity areas to HCHO cannot be underestimated. Industrial and civil sources have great influence on HCHO. In addition, the potential source of HCHO in Shanghai is affected by local emission sources, trans-regional potential sources, northwest air mass and ocean airflow.
... The atmosphere over this region is highly affected by the increase in pollutants driven by anthropogenic activities. Intense sunlight and high water vapour are the meteorological factors that modify the pollutant concentrations in these latitudes Kuttippurath et al., 2022a). Therefore, to analyse the air quality changes due to tropospheric ozone, we have also divided the study area into six sub-regions, namely: (i) Hilly region, consisting of Jammu Kashmir, Uttarakhand, Himachal Pradesh, Arunachal Pradesh and Sikkim. ...
... Higher concentrations of TPO are found in IGP, which may be due to the presence of high O 3 precursors, including HCHO and NO 2 in these regions. The primary source of HCHO is isoprene (precursor) and is found to be higher in the north IGP (Kuttippurath et al., 2022a). In addition, these overpopulated areas with large cities and vast agricultural lands account for the high concentrations of HCHO. ...
... In the northeast and IGP, there are frequent fire events compared to other regions of India, mainly from March to May and October to November (Kuttippurath et al., 2022a). Also, the stubble and biomass burning in the northeast and IGP regions account for an increase in tropospheric ozone (David and Nair, 2013). ...
At higher concentrations, tropospheric ozone can cause respiratory difficulties, premature human mortality and can harm vegetation by reducing photosynthesis and its growth. It is an oxidant and also an important green- house gas with positive feedback to temperature. It is produced as a byproduct of chemical reactions involving nitrogen oxides (NO ) and volatile organic compounds (VOCs) in the presence of sunlight, rather than being emitted directly to the atmosphere. Here, we analyse the seasonal and inter-annual variability, long-term trends and radiative forcing of the tropospheric column ozone (TPO) in India for the period of 2005–2020 using satellite and ground-based data. The analysis shows very high annual averaged TPO in the Indo-Gangetic Plain (IGP) and North West India, about 45–50 DU. Our findings reveal a significant increase of TPO in India, with the highest trend in the peninsular region (0.295 ± 0.0617 DU/year) and the lowest in North West (0.179 ± 0.048 DU/ year). The increase in tropospheric ozone reveals a warming of about 0.5 °C in the troposphere as there is an as- sociated radiative forcing of about 0.2–0.5 W/m 2 at the tropopause (125 hPa); indicating that the increasing tropospheric ozone is a great concern for regional warming, public health and ecosystem dynamics.
... The stubble burning during the wheat-rice rotation period is among the prominent reasons for a seasonal increase in NO 2 in this region. 4,46,47 Major stubble burning occurs during January-May in Lahore, Faisalabad, Dera Ghazi Khan, Narowal and Hazabad in Pakistan, Punjab, Haryana, Himachal Pradesh, Uttarakhand, Uttar Pradesh and Bihar in India, Nepal and Myanmar. 44,48 The re count data also reveal an increase in the number of res, particularly during MAM when compared to other seasons (Fig. S3 †). ...
... Major stubble burning occurs during October-May in the IGP, YYRB, Nepal, Myanmar and East Asia. 4,44,46 However, large areas on the southern slope of the TP, including Nepal, Bhutan, Bangladesh, Northeast India, Myanmar, East Asia and some regions of the YYRB, are covered with broadleaf forest, and the re count frequency is high during December-June there, as illustrated in Fig. S2. † Fig. 7 (bottom) shows the NO 2 pollution through road transport in the TP, which are very small (<4 Tg year −1 ) in Nepal, Bhutan and Myanmar. ...
The Third Pole, Hindu Kush Himalaya (HKH) and Tien Shan mountains, has been closely monitored for the past few decades because of its deteriorating environmental condition. Here, we analyse the spatio-temporal changes in tropospheric NO2 over TP using satellite observations from 2005 to 2020. The highest NO¬2 concentrations (i.e. ≥ 1 × 1015 molec. cm-2) are found in the boundaries close to Indo-Gangetic Plain (IGP), and Yellow and Yangtze River basins (YYRB). The analysis of Emissions Database for Global Atmospheric Research (EDGAR v6.1) shows that the main contribution to NO2 in the region is from the road transport (81%) and then power sector (7%). The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) analyses illustrate that the major regions from which air mass reach TP is from IGP, Southeast Asia, YYRB, Central Asia and Middle East. Our analysis reveals a positive trend in NO2 over most regions of TP (up to 0.05 ± 0.01 × 1015 molec. cm-2 year-1) in the yearly averaged data for the period 2005–2020, which suggest that the pollution is spreading even to the inner regions of TP. Therefore, this study reveals that the inner TP, one of the most pristine regions on the earth, is getting polluted because of high anthropogenic activities within and nearby areas/cities; indicating the impact of regional development activities and socioeconomic changes in recent years.
... Средняя скорость возрастания составила 0,003 мг/м 3 в год или 68% в год. За этот же период тренды, рассчитанные по среднегодовым данным, показывают статистически значимые положительные возрастания по регионам и морским портам Индии около 5 % [16]. Над нефтеносными песками Холодного озера на юге Альберты в Канаде с 2005 по 2014 год концентрация HCHO увеличилась на 3,8% в год, что согласуется с увеличением добычи сырой нефти там [17]. ...
... Над нефтеносными песками Холодного озера на юге Альберты в Канаде с 2005 по 2014 год концентрация HCHO увеличилась на 3,8% в год, что согласуется с увеличением добычи сырой нефти там [17]. Надо отметить, что в работах [16,17] содержание HCHO было определено с помощью спутниковой аппаратуры. Несмотря на это можно сделать вывод, что в период с 2006 по 2011 годы скорость возрастания среднегодовой концентрации HCHO в атмосфере Красноярска была в десятки раз выше, чем в других регионах мира. ...
Исследован характер изменения концентрации формальдегида в приземном слое атмосферы миллионного промышленного города центральной Сибири. Показано, что в 2009- 2010 году скачкообразно возросло содержание формальдегида в воздушной среде г. Красноярска. Характер годовой динамики концентрации формальдегида при этом не изменился. Однако, после 2010 года увеличилось среднемесячное содержание формальдегида в атмосфере.
