G. Löschau

Sächsisches Staatsministerium für Umwelt und Landwirtschaft, Dresden, Saxony, Germany

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Publications (24)33.44 Total impact

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    ABSTRACT: The German Ultrafine Aerosol Network (GUAN) is a cooperative atmospheric observation network, which aims at improving the scientific understanding of aerosol-related effects in the troposphere. The network addresses research questions dedicated to both, climate and health related effects. GUAN's core activity has been the continuous collection of tropospheric particle number size distributions and black carbon mass concentrations at seventeen observation sites in Germany. These sites cover various environmental settings including urban traffic, urban background, rural background, and Alpine mountains. In association with partner projects, GUAN has implemented a high degree of harmonisation of instrumentation, operating procedures, and data evaluation procedures. The quality of the measurement data is assured by laboratory intercomparisons as well as on-site comparisons with reference instruments. This paper describes the measurement sites, instrumentation, quality assurance and data evaluation procedures in the network as well as the EBAS repository, where the data sets can be obtained (doi:10.5072/guan).
    No preview · Article · Nov 2015
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    Alexander Schladitz · Jan Lenícek · Ivan Benes · Martin Kovác · Jirí Skorkovský · Ales Soukup · Jana Jandlova · Laurent Poulain · Helena Placha · Gunter Löschau · Alfred Wiedensohler
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    ABSTRACT: A comprehensive air quality study has been carried out at two urban background sites in Annaberg-Buchholz (Germany) and Ústí nad Labem (Czech Republic) in the German–Czech border region between January 2012 and June 2014. Special attention was paid to quantify harmful fractions of particulate matter (PM) and ultrafine particle number concentration (UFP) from solid fuel combustion and vehicular traffic. Source type contributions of UFP were quantified by using the daily concentration courses of UFP and nitrogen oxide. Two different source apportionment techniques were used to quantify relative and absolute mass contributions: positive matrix factorization for total PM2.5 and elemental carbon in PM2.5 and chemical mass balance for total PM1 and organic carbon in PM1. Contributions from solid fuel combustion strongly differed between the non-heating period (April–September) and the heating period (October–March). Major sources of solid fuel combustion in this study were wood and domestic coal combustion, while the proportion of industrial coal combustion was low (<3%). In Ústí nad Labem combustion of domestic brown coal was the most important source of organic carbon ranging from 34% to 43%. Wood combustion was an important source of organic carbon in Annaberg-Buchholz throughout the year. Heavy metals and less volatile polycyclic aromatic hydrocarbons (PAH) in the accumulation mode were related to solid fuel combustion with enhanced concentrations during the heating period. In contrast, vehicular PAH emissions were allocated to the Aitken mode. Only in Ústí nad Labem a significant contribution of photochemical new particle formation (e.g. from sulfur dioxide) to UFP of almost 50% was observed during noontime. UFPs from traffic emissions (nucleation particles) and primary emitted soot particles dominated at both sites during the rest of the day. The methodology of a combined source apportionment of UFP and PM can be adapted to other regions of the world with similar problems of atmospheric pollution to calculate the relative risk in epidemiological health studies for different sub-fractions of PM and UFP. This will enhance the meaningfulness of published relative risks in health studies based on total PM and UFP number concentrations.
    Full-text · Article · Sep 2015 · Atmospheric Environment
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    Full-text · Dataset · Jul 2015
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    ABSTRACT: An automated function control unit was developed to regularly check the ambient particle number concentration derived from a mobility particle size spectrometer as well as its zero-point behaviour. The function control allows unattended quality assurance experiments at remote air quality monitoring or research stations under field conditions. The automated function control also has the advantage of being able to get a faster system stability response than the recommended on-site comparisons with reference instruments. The method is based on a comparison of the total particle number concentration measured by a mobility particle size spectrometer and a condensation particle counter while removing diffusive particles smaller than 20 nm in diameter. In practice, the small particles are removed by a set of diffusion screens, as traditionally used in a diffusion battery. Another feature of the automated function control is to check the zero-point behaviour of the ambient aerosol passing through a high-efficiency particulate air (HEPA) filter. The performance of the function control is illustrated with the aid of a 1-year data set recorded at Annaberg-Buchholz, a station in the Saxon air quality monitoring network. During the period of concern, the total particle number concentration derived from the mobility particle size spectrometer slightly overestimated the particle number concentration recorded by the condensation particle counter by 2 % (grand average). Based on our first year of experience with the function control, we developed tolerance criteria that allow a performance evaluation of a tested mobility particle size spectrometer with respect to the total particle number concentration. We conclude that the automated function control enhances the quality and reliability of unattended long-term particle number size distribution measurements. This will have beneficial effects for intercomparison studies involving different measurement sites, and help provide a higher data accuracy for cohort health and climate research studies.
    Full-text · Article · Apr 2014 · Atmospheric Measurement Techniques
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    ABSTRACT: The city of Leipzig established a low emission zone (LEZ) on March 1, 2011, being the first LEZ in Germany where the highest regulation level 3 was introduced immediately. The Saxon State Office for Environment, Agriculture and Geology, Dresden, and TROPOS Leipzig implemented specialized measurements of ambient black carbon (BC) mass concentrations and particle number size distributions at five monitoring sites. First trend analyses suggest a decrease in BC and particle number concentration (diameter 50 to 100 nm) in the vicinity of roads as a result of the LEZ. This decrease seems to be first, an effect of decreasing traffic volumes in the area of the LEZ and only second, an effect of reductions in the vehicles' exhaust emission factors. For PM10 mass concentrations, no decrease could be observed. This study concludes that the LEZ can be very effective in reducing the ambient concentrations of health-related particulate matter parameters BC and particle number, even if the beneficial effects are not evident from the legal parameter PM10 mass concentration.
    No preview · Article · Nov 2013 · Gefahrstoffe Reinhaltung der Luft
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    A Schladitz · G Löschau · H.-G Kath
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    ABSTRACT: Importance in monitoring the particulate soot content in the atmosphere  Health effect of soot particles WHO (REVIHAAP project): "…black carbon particles are a valuable additional air quality metric to evaluate the health risks of primary combustion particles from traffic…"  Climate effect of soot particles ICCP report reveals: "…black carbon is identified as having a significant anthropogenic component and exerting a significant direct radiative forcing…" The project is co-financed by the European Regional Development Fund (ERDF) Different method-dependent definitions for black carbon (BC) and elemental carbon (EC)  literature reveal significant correlations of EC and BC (Hitzenberger et al., 2006; Park et al., 2006; Schmid et al., 2001; Petzold et al., 2004)  but the results are dependent on: • used mass absorption coefficient to convert optical signal into BC mass concentration • thermal analyzing protocol for EC determination (e.g., IMPROVE, VDI 2465, part 1+2) • classification of the measurement station (e.g., urban, rural) Two analyzing methods for soot particles in an air quality monitoring network
    Full-text · Conference Paper · Sep 2013
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    A. Schladitz · G. Löschau · A. Wiedensohler

    Full-text · Conference Paper · May 2013
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    Full-text · Dataset · Nov 2012
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    A. Schladitz · G. Löschau · A. Hausmann

    Full-text · Conference Paper · Jun 2012
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    ABSTRACT: Mobility particle size spectrometers often referred to as DMPS (Differential Mobility Particle Sizers) or SMPS (Scanning Mobility Particle Sizers) have found a wide range of applications in atmospheric aerosol research. However, comparability of measurements conducted world-wide is hampered by lack of generally accepted technical standards and guidelines with respect to the instrumental set-up, measurement mode, data evaluation as well as quality control. Technical standards were developed for a minimum requirement of mobility size spectrometry to perform long-term atmospheric aerosol measurements. Technical recommendations include continuous monitoring of flow rates, temperature, pressure, and relative humidity for the sheath and sample air in the differential mobility analyzer. We compared commercial and custom-made inversion routines to calculate the particle number size distributions from the measured electrical mobility distribution. All inversion routines are comparable within few per cent uncertainty for a given set of raw data. Furthermore, this work summarizes the results from several instrument intercomparison workshops conducted within the European infrastructure project EUSAAR (European Supersites for Atmospheric Aerosol Research) and ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) to determine present uncertainties especially of custom-built mobility particle size spectrometers. Under controlled laboratory conditions, the particle number size distributions from 20 to 200 nm determined by mobility particle size spectrometers of different design are within an uncertainty range of around ±10% after correcting internal particle losses, while below and above this size range the discrepancies increased. For particles larger than 200 nm, the uncertainty range increased to 30%, which could not be explained. The network reference mobility spectrometers with identical design agreed within ±4% in the peak particle number concentration when all settings were done carefully. The consistency of these reference instruments to the total particle number concentration was demonstrated to be less than 5%. Additionally, a new data structure for particle number size distributions was introduced to store and disseminate the data at EMEP (European Monitoring and Evaluation Program). This structure contains three levels: raw data, processed data, and final particle size distributions. Importantly, we recommend reporting raw measurements including all relevant instrument parameters as well as a complete documentation on all data transformation and correction steps. These technical and data structure standards aim to enhance the quality of long-term size distribution measurements, their comparability between different networks and sites, and their transparency and traceability back to raw data.
    Full-text · Article · Mar 2012 · Atmospheric Measurement Techniques
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    ABSTRACT: The fractions of local traffic (LT), urban background (UBG) and regional background (RBG) of the particle pollution at a traffic-influenced kerbside in Dresden, Germany, were determined by measurements of size-segregated mass concentration, chemical composition and particle size distributions in a network of five measurement stations partly existing and partly set up for this study. Besides the kerbside station, one urban background site and three rural sites were included in the study. Using data from these different sites, the LT, UBG, and RBG contributions were calculated, following the approach of Lenschow et al. (2001). At the kerbside site, 19% of the total number concentration (Dp(St) = 10-600 nm) could be attributed to the RBG, 15% to the UBG, and 66% to the LT immediately nearby. Particle mass concentrations up to Dp(aer) = 420 nm RBG amounts to 68%, UBG to 21%, and LT only to 11%. Highest mass concentrations were observed at all stations in autumn and winter during easterly inflow directions. The local traffic fraction of PM10 mass at the kerbside station was found to be 30% for westerly inflow, but only 7% for southeasterly inflow due to the dominating transport fraction from up to 80% of the particle mass at this inflow direction. Size-resolved investigation showed the main fractions in both the particle size ranges of Dp(aer) = 0.42 to 1.2 and 0.14 to 0.42 mu m at all stations. The main components sulphate, ammonium and total carbon showed higher concentrations at south-eastern/eastern inflow in autumn at all stations, while nitrate at the kerbside and urban background site was higher during westerly inflow in winter. The chemical composition at the regional background site at westerly inflow (12% nitrate, 8% sulphate, 11% total carbon) was significantly different from that at easterly inflow (3% nitrate, 15% sulphate, 22% total carbon). The prevailing part of the ionic mass was always found in the fine particle range of Dp(aer) = 0.14 to 1.2 mu m at all stations. For all inflow directions highest total carbon concentrations were observed at the kerbside station, especially in the ultra-fine size range of Dp(aer) = 0.05 to 0.14 mu m with up to 30% of the whole carbon. PAH concentrations were always higher at south-eastern/eastern inflow especially during wintertime. Trace metal components and silicon were found mainly in the coarse mode fraction at the kerbside resulting from abrasion or resuspension.
    No preview · Article · Sep 2011 · Journal of Atmospheric Chemistry
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    ABSTRACT: The ambient air quality with respect to particle concentrations was investigated at five selected monitoring sites in Saxony in a measurement campaign over a period of 6 months in 2006 and 2007. The mean particle number concentration in the regional background was approximately 3,600 particles per cm(3), about twice as high in the urban background and more than five times higher close to a busy street. The mean particle number size distribution at the roadside had its maximum at 16 nm in the size range from 3 nm to 800 nm. The maximum in the urban background was 35 am and about 70 nm in the regional background. The mass concentration of soot particles was about 10 times higher compared to the regional background and contributed 3 % to PM(10) mass concentration. The effect of the traffic emissions on the particle number concentration was found to be 10 to 20 higher than on PM(10).
    No preview · Article · Jan 2011 · Gefahrstoffe Reinhaltung der Luft
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    ABSTRACT: Residential wood burning is becoming an increasingly important cause of air quality problems since it has become a popular source of alternative energy to fossil fuel. In order to characterize the contribution of residential wood burning to local particle pollution a field campaign was organized at the village of Seiffen (Saxony, Germany). During this campaign, an Aerosol Mass Spectrometer (AMS) was deployed in parallel to a PM1 high volume filter sampler. The AMS mass spectra were analyzed using Positive Matrix Factorization (PMF) to obtain detailed information about the organic aerosol (OA). Biomass-burning organic aerosol (BBOA), Hydrocarbon-like organic aerosol (HOA), Low-volatility oxygenated organic aerosol (LV-OOA) and Semi-volatile oxygenated organic aerosol (SV-OOA) were identified. Additionally, Polycyclic Aromatic Hydrocarbons (PAH) were measured by the AMS and short term events of extremely high PAH concentration compared to the mean PAH value were observed during the whole measurement period. A comparison with the results from PM1 filter samples showed that the BBOA factor and the AMS PAH are good indicators of the total concentration of the different monosaccharide anhydrides and PAH measured on the filter samples. Based on its correlation with CO and the low car traffic, the HOA factor was considered to be related to residential heating using liquid fuel. A clear impact of the week and weekend days on the diurnal profiles of the different OA components was observed. The weekdays were characterized by two maxima; a first one early in the morning and a stronger one in the evening; during the weekend days, the different OA components principally reached one maxima early in the afternoon. Finally, the PAH emitted directly from residential wood combustion was estimated to represent 1.5% of the total mass of BBOA factor and around 62% of the total PAH concentration measured at Seiffen. This result highlights the important contribution of residential wood combustion to air quality and PAH emissions at the sampling place which might have a significant impact on human health. Moreover, it also emphasizes the need for a better time resolution of the chemical characterization of toxic particulate compounds in order to provide more information about variations of the different sources through the days as well as to better estimate the real human exposure.
    Full-text · Article · Jan 2011 · Atmospheric Chemistry and Physics

  • No preview · Conference Paper · Aug 2010
  • G. Loeschau · A Wiedensohler · B. Wehner · W. Birmili · H. Gerwig
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    ABSTRACT: Ultrafine particles have been measured in ambient air at a traffic site in Dresden for nine years using a TDMPS (Twin Differential Particle Mobility Sizer) and were classified in eight size classes in the range from 3 to 800 nm. The level of the particle concentration was about 20 000 particles per cm(3) in the range from 10 to 800 nm in the period from 2001 to 2006. The level decreased by about 25% in the following period from 2007 to 2009. The particle class 200 to 800 nm correlates well with PM(2.5). This correlation can be used to check the plausibility of both measurement methods. Parameters to estimate the average particle number concentrations in specified size classes from measured NO(x), soot and PM(2.5) concentrations were derived.
    No preview · Article · May 2010 · Gefahrstoffe Reinhaltung der Luft
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    ABSTRACT: This paper synthesizes data on aerosol (particulate matter, PM) physical and chemical characteristics, which were obtained over the past decade in aerosol research and monitoring activities at more than 60 natural background, rural, near-city, urban, and kerbside sites across Europe. The data include simultaneously measured PM10 and/or PM2.5 mass on the one hand, and aerosol particle number concentrations or PM chemistry on the other hand. The aerosol data presented in our previous works ( [45] and [29]) were updated and merged to those collected in the framework of the EU supported European Cooperation in the field of Scientific and Technical action COST633 (Particulate matter: Properties related to health effects). A number of conclusions from our previous studies were confirmed. There is no single ratio between PM2.5 and PM10 mass concentrations valid for all sites, although fairly constant ratios ranging from 0.5 to 0.9 are observed at most individual sites. There is no general correlation between PM mass and particle number concentrations, although particle number concentrations increase with PM2.5 levels at most sites. The main constituents of both PM10 and PM2.5 are generally organic matter, sulfate and nitrate. Mineral dust can also be a major constituent of PM10 at kerbside sites and in Southern Europe. There is a clear decreasing gradient in SO42− and NO3− contribution to PM10 when moving from rural to urban to kerbside sites. In contrast, the total carbon/PM10 ratio increases from rural to kerbside sites. Some new conclusions were also drawn from this work: the ratio between ultrafine particle and total particle number concentration decreases with PM2.5 concentration at all sites but one, and significant gradients in PM chemistry are observed when moving from Northwestern, to Southern to Central Europe. Compiling an even larger number of data sets would have further increased the significance of our conclusions, but collecting all the aerosol data sets obtained also through research projects remains a tedious task.
    Full-text · Article · Mar 2010 · Atmospheric Environment
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    ABSTRACT: Since the end of 2008 the German Ultrafine Aerosol Network (GUAN), an atmospheric observation network designed for long-term observations, is operational. The measurements are targeted at improving the description of the environmental aerosol (particulate matter), focussing on parameters that are relevant for human exposure but also climate effects. The measurements include sub-pm particle number size distributions, soot mass concentrations, and size-segregated chemical composition at a number of up to eleven observation sites. Specialised campaign measurements are added for a deeper understanding of the properties, sources, and processes related to ultrafine particles and soot. First observations from December 2008 and January 2009 illustrate the value of the network when characterising spatial and temporal effects in the atmospheric aerosol over an area such as Germany.
    Full-text · Article · Apr 2009 · Gefahrstoffe Reinhaltung der Luft
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    ABSTRACT: Since the end of 2008 the German Ultrafine Aerosol Network (GUAN), an atmospheric observation network designed for long-term observations, is operational. The measurements are targeted at improving the description of the environmental aerosol (particulate matter), focussing on parameters that are relevant for human exposure but also climate effects. The measurements include sub-pm particle number size distributions, soot mass concentrations, and size-segregated chemical composition at a number of up to eleven observation sites. Specialised campaign measurements are added for a deeper understanding of the properties, sources, and processes related to ultrafine particles and soot. First observations from December 2008 and January 2009 illustrate the value of the network when characterising spatial and temporal effects in the atmospheric aerosol over an area such as Germany.
    Full-text · Article · Apr 2009 · Gefahrstoffe Reinhaltung der Luft
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    ABSTRACT: On 24 March 2007, an extraordinary dust plume was observed in the Central European troposphere. Satellite observations revealed its origins in a dust storm in Southern Ukraine, where large amounts of soil were resuspended from dried-out farmlands at wind gusts up to 30 m s−1. Along the pathway of the plume, maximum particulate matter (PM10) mass concentrations between 200 and 1400 μg m−3 occurred in Slovakia, the Czech Republic, Poland, and Germany. Over Germany, the dust plume was characterised by a volume extinction coefficient up to 400 Mm−1 and a particle optical depth of 0.71 at wavelength 0.532 μm. In-situ size distribution measurements as well as the wavelength dependence of light extinction from lidar and Sun photometer measurements confirmed the presence of a coarse particle mode with diameters around 2–3 μm. Chemical particle analyses suggested a fraction of 75% crustal material in daily average PM10 and up to 85% in the coarser fraction PM10–2.5. Based on the particle characteristics as well as a lack of increased CO and CO2 levels, a significant impact of biomass burning was ruled out. The reasons for the high particle concentrations in the dust plume were twofold: First, dust was transported very rapidly into Central Europe in a boundary layer jet under dry conditions. Second, the dust plume was confined to a relatively stable boundary layer of 1.4–1.8 km height, and could therefore neither expand nor dilute efficiently. Our findings illustrate the capacity of combined in situ and remote sensing measurements to characterise large-scale dust plumes with a variety of aerosol parameters. Although such plumes from Southern Eurasia seem to occur rather infrequently in Central Europe, its unexpected features highlights the need to improve the description of dust emission, transport and transformation processes needs, particularly when facing the possible effects of further anthropogenic desertification and climate change.
    Full-text · Article · Feb 2008 · ATMOSPHERIC CHEMISTRY AND PHYSICS
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    ABSTRACT: On 24 March 2007, the atmosphere over Central Europe was affected by an episode of exceptionally high mass concentrations of aerosol particles, most likely caused by a dust storm in the Southern Ukraine on the preceding day. At ground-based measurement stations in Slovakia, the Czech Republic, Poland and Germany PM10 mass concentrations rose to values between 200 and 1400 μg m−3. An evaluation of PM10 measurements from 360 monitoring stations showed that the dust cloud advanced along a narrow corridor at speeds of up to 70 km h−1. According to lidar observations over Leipzig, Germany, the high aerosol concentrations were confined to a homogeneous boundary layer of 1800 m height. The wavelength dependence of light extinction using both lidar and sun photometer measurements suggested the dominance of coarse particles during the main event. At a wavelength of 532 nm, relatively high volume extinction coefficients (300–400 Mm−1) and a particle optical depth of 0.65 was observed. In-situ measurements with an aerodynamic particle sizer at Melpitz, Germany, confirmed the presence of a coarse particle mode with a mode diameter >2 μm, whose maximum concentration coincided with that of PM10. A chemical particle analysis confirmed the dominance of non-volatile and insoluble matter in the coarse mode as well as high enrichments of Ti and Fe, which are characteristic of soil dust. A combination of back trajectory calculations and satellite images allowed to identify the dust source with confidence: On 23 March 2007, large amounts of dust were emitted from dried-out farmlands in the southern Ukraine, facilitated by wind gusts up to 100 km h−1. The unusual vertical stability and confined height of this dust layer as well as the rapid transport under dry conditions led to the conservation of high aerosol mass concentrations along the transect and thus to the extraordinary high aerosol concentrations over Central Europe. Our observations demonstrate the capacity of a combined apparatus of in situ and remote sensing measurements to characterise such a dust with a variety of aerosol parameters. As a conclusion, the description of dust emission, transport and transformation processes needs to be improved, especially when facing the possible effects of further anthropogenic desertification and climate change.
    Full-text · Article · Aug 2007 · Atmospheric Chemistry and Physics