S. Gilge | Deutscher Wetterdienst (original) (raw)

Papers by S. Gilge

Aerobiologia

Standards for manual pollen and fungal spore monitoring have been established based on several de... more Standards for manual pollen and fungal spore monitoring have been established based on several decades of experience, tests, and research. New technological and methodological advancements have led to the development of a range of different automatic instruments for which no standard yet exist. This paper aims to provide an overview of aspects that need to be considered for automatic pollen and fungal spore monitoring, including a set of guidelines and recommendations. It covers issues relevant to developing an automatic monitoring network, from the instrument design and calibration through algorithm development to site selection criteria. Despite no official standard yet existing, it is essential that all aspects of the measurement chain are carried out in a manner that is as standardised as possible to ensure high-quality data and information can be provided to end-users.

$Research paper thumbnail of Ozone profiles over the Atlantic Ocean between 36$^\circ$ S and 52$^\circ$ N north in March/April 1987 and September/October 1988$

Vertical ozone soundings were performed during two scientific shipcruises, ANT-V/5 and ANT-VII/1,... more Vertical ozone soundings were performed during two scientific shipcruises, ANT-V/5 and ANT-VII/1, of the research vessel "Polarstern" over the Atlantic Ocean between 30 °S and 52 °N in March/April 1987 and September/October 1988, respectively. Vertical profiles of ozone and meteorological parameters like pressure, temperature and relative humidity were measured at different latitudes to obtain meridional distributions of tropospheric/lower stratospheric ozone and water vapor during two different seasons. In this volume we will report the results of the individual soundings and the derived meridional distributions of ozone and water vapor measured during the two cruises

EGU General Assembly Conference Abstracts, Apr 1, 2015

Der Einfluss von Bebauung auf die Schadstoffverteilung in der innerörtlichen At... more Der Einfluss von Bebauung auf die Schadstoffverteilung in der innerörtlichen Atmosphäre und damit auf die Gesundheit des Menschen ist grundsätzlich von großem Interesse, insbesondere im Hinblick auf den Kurbetrieb und die Erfolgsaussichten einer medizinischen Behandlung bzw. Rehabilitation. Das Zentrum für Medizin-Meteorologische Forschung (ZMMF) des Deutschen Wetterdienstes stellt mit seinen Messreihen sicher, dass die Luftqualität in Kurorten entsprechend gut ist. Um die Ortschaften bei der Entwicklung von Strategien zur Luftqualitätsverbesserung noch besser unterstützen zu können sollen zukünftig auch Modellrechnungen mit  PALM-4U (PALM for urban applications) durchgeführt werden. Dieses Modell erlaubt die Simulation sehr genauer Strömungs- und Turbulenzverhältnisse in der Nähe von sehr komplexen Hindernissen unter Einbindung von urbanen Einflussfaktoren wie zum Beispiel Schadstoffquellen aus dem Verkehr oder der Beheizung. In diesem Beitrag sollen die Anwendungsmöglichkeiten von PALM-4U am ZMMF aufgezeigt werden. Als Beispiel dient hierfür eine teilrealistische Ortschaft, welche teilweise dem Ort Prüm in der Eifel nachempfunden ist. Das Gelände ist stark orographisch gegliedert, die Bebauung wurde in der Genauigkeit LOD1 (level of detail 1) eingebunden. Es werden beispielhaft die Auswirkungen auf die Belastung durch NO2, PM10 und bodennahem O3 bei Änderungen der Verkehrsdichte und zusätzlich bei Einführung einer Umgehungsstraße untersucht. Des Weiteren werden Änderungen in der Schadstoffausbreitung bei Anpassungen in der Bebauung dargestellt sowie der Einfluss einzelner Schadstoffquellen auf die nähere Umgebung bei komplexer Bebauung. Somit lässt sich das Potential zur Schadstoffreduktion bei verschiedenen städtebaulichen oder anderen Anpassungsmaßnahmen abschätzen.

The Eyjafjallajökull volcano eruptions during mid April 2010 influenced European air traffic basi... more The Eyjafjallajökull volcano eruptions during mid April 2010 influenced European air traffic basically. This was mainly due to the low melting point of ejected material and the sharp-edged form of particles. As there is the necessity to understand the dispersion of such an ash cloud we assess the existing measurement networks and evaluate the existing numerical models (MCCM). We use

Aerobiologia, 2020

Operational pollen monitoring networks have developed across Europe, and the world more generally... more Operational pollen monitoring networks have developed across Europe, and the world more generally, in response to the increasing prevalence of pollen allergy and asthma. Routine pollen observations are in large part currently still based on time-intensive manual techniques developed in the 1950s. These methods suffer from low temporal resolution and long delays in data availability. Recent technological developments are revolutionising the field making real-time high-temporal resolution measurements possible. This paper describes the rationale behind the EUMETNET AutoPollen programme, which aims to develop a prototype automatic pollen monitoring network across Europe. We provide a brief description of the current state-of-the-art, then an overview of new technologies, and finally the main tasks of the AutoPollen programme.

Aerobiologia

Pollen monitoring has traditionally been carried out using manual methods first developed in the ... more Pollen monitoring has traditionally been carried out using manual methods first developed in the early 1950s. Although this technique has been recently standardised, it suffers from several drawbacks, notably data usually only being available with a delay of 3–9 days and usually delivered at a daily resolution. Several automatic instruments have come on to the market over the past few years, with more new devices also under development. This paper provides a comprehensive overview of all available and developing automatic instruments, how they measure, how they identify airborne pollen, what impacts measurement quality, as well as what potential there is for further advancement in the field of bioaerosol monitoring.

In order to reach legal air quality limits, several municipalities in Germany have decid... more In order to reach legal air quality limits, several municipalities in Germany have decided to take actions if concentrations of NO2 and Particulate Matter (PM) exceed certain thresholds. The decision for concrete measures is usually based on observations or use the Direct Model Output (DMO) of air quality models. However, due to large biases of state-of-the-art numerical air quality models, the skill of DMO forecasts to predict periods of polluted air up to four days ahead is very limited.The project LQ-WARN aims to develop a system for warning of poor air quality based on Model Output Statistics (MOS). Therefore, air quality related observations, model results provided by the Copernicus Atmosphere Monitoring Service (CAMS) and meteorological parameters from the ECMWF numerical weather prediction model are used as predictors to forecast the air quality by applying Multiple Linear Regression (MLR). In this way MOS equations are calculated for four seasons. The final forecast product will comprise post-processed probabilistic as well as deterministic (e.g. mass concentration) parameters for the species NO2, O3, PM10 and PM2.5. Forecasts will be available for several hundred German locations and cover lead times up to 96 hours.Here, we show first results of our phase 1 MOS prototype, for which observational, meteorological and empirical predictors are applied. Despite of the preliminary exclusion of CAMS predictors, the verifications of the MOS equations imply a considerable reduction of variance and a significant reduction of RMSE (Root Mean Square Error) compared to the climatological values for all four species. Hence, the MOS system can already provide a reasonably good air quality forecast. Furthermore, our analysis of used meteorological predictors, enables a detailed analysis of the importance of specific meteorological parameters for improved statistical air quality forecasts.  As an outlook we will provide detailed information about the final phase 2 LQ-WARN product, which will also include the MOS predictors of CAMS and is expected to be launched in pre-operational mode by 2022.

ISSN 0944-2952, 1994

Continuous measurements ofH202and organic hydroperoxides were performed at the field station Scha... more Continuous measurements ofH202and organic hydroperoxides were performed at the field station Schauinsland between January 1989 and June 1991 using an ezyme catalysed fluorescence instrument. The mixing ratios were in the range of the detection limit (20 ppt) up to 4.4 ppb for ~Oz and 1.7 ppb for ROOR. Both Hz02 and ROOH show a strong seasonal variation with maximum concentrations in summer. The observed seasonal trend is in line with the photochemical formation mechanism on the one hand and the main atmospheric loss processes on the other hand. The mixing ratios ofHz02 and ROOH are strongly influenced by wet deposition. For interpretation ofthe behavior ofthese substances in gas phase, this influence has to be eliminated. This was achieved by selecting sunny periods from the whole data set. In addition, periods were selected, where production exeeds chemical losses, because then, the measured concentrations of photochemically produced species, in first approximation, should reflect their production rates. This is the case when air masses arrive at Schauinsland from the nearby city of Freiburg and Rhine valley during summer and daytime. Comparison of results of smog chamber experiments performed by Hess et al. (1992 a.b,c) with chemical box model calculations using the EURORADM mechanism (Stockwell and Kley, 1994) showed, that a positive slope in the H20/Ox ratio with increasing photochemical age is an indicator for NOx limitation of photochemical ozone production. The box model was initialized using typical NOx start concentrations and VOCINOx ratios for the Schauinsland site. Analysis ofthe measured concentration ratios ofH202 and Ox versus the photochemical age of the air masses gave the result, that a large fraction of these measurements already fall into thecategory where theozone production isNOx limited. For this analysis only data were used, where the station was influenced by fresh anthropogenic emissions from Freiburg and the Rhine Valley, i.e. the analysed air masses were exposed to anthropogenic emissions later than four hours before arrival at the site. Since the advected air mass from other wind sectors are photochemically further processed, because anthropogenic sources are more distant, it C3Jl be coneluded that at Schauinsland the photochemical ozone production is in most cases limited by the availibility ofNOx' Since Schauinsland is relative dose to a large anthropogenic pollution source, this conclusion shoud be also valid for most rural areas in Europe

This paper concerns an evaluation of ozone (O 3) and planetary boundary layer (PBL) dynamics over... more This paper concerns an evaluation of ozone (O 3) and planetary boundary layer (PBL) dynamics over the complex topography of the Grenoble region through a combination of measurements and mesoscale model (METPHO-MOD) predictions for three days, during July 1999. The measurements of O 3 and PBL structure were obtained with a Differential Absorption Lidar (DIAL) system, situated 20 km south of Grenoble at Vif (310 m ASL). The combined lidar observations and model calculations are in good agreement with atmospheric measurements obtained with an instrumented aircraft (METAIR). Ozone fluxes were calculated using lidar measurements of ozone vertical profiles concentrations and the horizontal wind speeds measured with a Radar Doppler wind profiler (DEGREANE. The ozone flux patterns indicate that the diurnal cycle of ozone production is controlled by local thermal winds. The convective PBL maximum height was some 2700 m above the land surface while the nighttime residual ozone layer was generally found between 1200 and 2200 m. Finally we evaluate the magnitude of the ozone processes at different altitudes in order to estimate the photochemical ozone production due to the primary pollutants emissions of Grenoble city and the regional network of automobile traffic.

This report describes the development of a new analytical procedure for the measurement of H$_{2}... more This report describes the development of a new analytical procedure for the measurement of H$_{2}$O$_{2}$ and other soluble oxidants in the atmosphere. The main goal was to develop an instrument that is light-weight and relatively simple to operate so that it can be flown on meteorological balloons. H$_{2}$O$_{2}$ and its organic homologues are formed in the atmosphere from the recombination of peroxy radicals (HO$_{2}$ and RO$_{2}$). It is thus interesting for the understanding of the radical cycles. Because of its high solubility, H$_{2}$O$_{2}$ is considered to play an important role in the oxidation of SO$_{2}$ to H$_{2}$SO$_{4}$ in fog and cloud droplets. The instrument employs iodometry in combination with electrochemical detection and quantification by means of a modified electrochemical concentration cell as is used in commercial ozone sondes. The oxidation of I$^{-}$ to I$_{2}$, which in the case of H$_{2}$O$_{2}$ is extremely slow, can be sufficiently accelerated through the addition of a molybdate complex acting as a catalyst. Separation of the H$_{2}$O$_{2}$ from the more abundant non soluble oxidants, mainly ozone, is achieved by Henrys law, namely by first allowing the ambient air to be in contact with an aqueous stripping solution. While H$_{2}$O$_{2}$ and other well soluble species are quantitavely dissolved in the water, only 0.003 % of the ozone are sampled. Interferences by reducing species, mainly SO$_{2}$, are avoided if necessary by using 0.5 M H$_{2}$SO$_{4}$ as a stripping solution. The instrument was tested in the laboratory and compared to an already established technique (enzyme catalyzed oxidation of p-hydroxy phenylacetic acid followed by fluorimetry) on our field station Schauinsland. The two instruments showed a very good agreement for measurements of ambient air under various conditions and for H$_{2}$O$_{2}$ concentrations ranging from 0.1 to 1 ppb

Atmospheric Chemistry and Physics, 2018

Abundance-based model evaluations with observations provide critical tests for the simulated mean... more Abundance-based model evaluations with observations provide critical tests for the simulated mean state in models of intercontinental pollution transport, and under certain conditions may also offer constraints on model responses to emission changes. We compile multiyear measurements of peroxy acetyl nitrate (PAN) available from five mountaintop sites and apply them in a proof-of-concept approach that exploits an ensemble of global chemical transport models (HTAP1) to identify an observational "emergent constraint". In April, when the signal from anthropogenic emissions on PAN is strongest, simulated PAN at northern midlatitude mountaintops correlates strongly with PAN source-receptor relationships (the response to 20 % reductions in precursor emissions within northern midlatitude continents; hereafter, SRRs). This finding implies that PAN measurements can provide constraints on PAN SRRs by limiting the SRR range to that spanned by the subset of models simulating PAN within the observed range. In some cases, regional anthropogenic volatile organic compound (AVOC) emissions, tracers of transport from different source regions, and SRRs for ozone also correlate with PAN SRRs. Given the large observed interannual variability in the limited available datasets, establishing strong constraints will require matching meteorology in the models to the PAN measurements. Application of this evaluation approach to the chemistry-climate models used to project changes in atmospheric composition will require routine, long-term mountaintop PAN measurements to discern both the climatological SRR signal and its interannual variability.

PRICE was organised as a formal comparison of different methods to measure peroxy radicals (HO$_{... more PRICE was organised as a formal comparison of different methods to measure peroxy radicals (HO$_{2}$ and RO$_{2}$). lt was conducted in summer 1994 at the TOR$^{1}$ -station Schauinsland in South-West Germany as a task of the EU-project OCTA$^{2}$. The comparison involved matrix isolation ESR spectroscopy (MIESR) and five chemical amplifiers (CA). The campaign lasted 5 weeks, with ambient measurements being performed over a time period of 2 weeks. Between and after the ambient measurements, the different calibration procedures used for the chemical amplifiers were compared. Data delivery was performed after a formal data protocol. At the beginning of the campaign, relatively large differences in the calibration of theLuminol-chemiluminescence instruments used for detection of the NO$_{2}$ from the chemical amplifiers were found for some groups. A meaningful comparison of the radical measurements thus required harmonisation of the NO$_{2}$ standards. This was achieved by tying all NO$_{2}$ measurements to the NO$_{2}$ calibration of the TOR station and by adopting a common procedure for taking the non-linear response of the Luminol detector into account. Thereafter, the different chemical amplifiers and MIESR agreed within 130% for measurements of HO$_{2}$ radicals produced artificially by H$_{2}$O photolysis. Somewhat larger discrepancies were found for a comparison with CH$_{3}$O$_{2}$ radicals produced by photolysis of CH$_{3}$I and for CH$_{3}$COO$_{2}$ radicals produced by thermolysis of PAN. In ambient air, all instruments found similar diurnal variations in the RO$_{2}$ concentrations, with maximum concentrations around or shortly after noon time. The correlation was best under situations with high wind speeds and low precursor concentrations. Overall, the chemical amplifiers seemed to have less dynamic range than the MIESR, with the highest RO$_{2}$ concentrations found by MIESR being underestimated by the chemical amplifiersby up to a factor of 2. Possible explanations are a lower conversion efficiency for large organic peroxy radicals and/or a strong inverse dependence of the chain length on the relative humidity that was found very recently in laboratory experiments and which was not accounted for by the calibration procedures during PRICE. The decrease in chainlength with increasing relative humidity would indeed bring the data from the chemical amplifiers into mach better agreement with MIESR. Given the magnitude of the effect and its sensitivity to fluctuations in ambient humidity and temperature, correction of the data in retrospect, however, will be extremely difficult if not impossible. Since high quality measurements of peroxy radicals ean provide deep insight in the degradation mechanism of organic compounds and photo-oxidant formation, a vital interest remains in the further development of the CA, including the conversion efficiencies for the higher organic peroxy radicals arid, most important, of the infiuence of humidity on the chain length.

Elem Sci Anth, 2015

Long-term observations of reactive gases in the troposphere are important for understanding trace... more Long-term observations of reactive gases in the troposphere are important for understanding trace gas cycles and the oxidation capacity of the atmosphere, assessing impacts of emission changes, verifying numerical model simulations, and quantifying the interactions between short-lived compounds and climate change. The World Meteorological Organization's (WMO) Global Atmosphere Watch (GAW) program coordinates a global network of surface stations some of which have measured reactive gases for more than 40 years. Gas species included under this umbrella are ozone, carbon monoxide, nitrogen oxides, and volatile organic compounds (VOCs). There are many challenges involved in setting-up and maintaining such a network over many decades and to ensure that data are of high quality, regularly updated and made easily accessible to users. This overview describes the GAW surface station network of reactive gases, its unique quality management framework, and discusses the data that are available from the central archive. Highlights of data use from the published literature are reviewed, and a brief outlook into the future of GAW is given. This manuscript constitutes the overview of a special feature on GAW reactive gases observations with individual papers reporting on research and data analysis of particular substances being covered by the program. Key reactive gases, which are also readily measurable, are tropospheric ozone, carbon monoxide, volatile organic compounds, reactive nitrogen gases, and reactive sulfur gases. Reactive gases play a dual role in the

Experiment (HOPE 2000): Measurements and photostationary state calculations of

Aerobiologia

$Research paper thumbnail of Ozone profiles over the Atlantic Ocean between 36$^\circ$ S and 52$^\circ$ N north in March/April 1987 and September/October 1988$

EGU General Assembly Conference Abstracts, Apr 1, 2015

Aerobiologia, 2020

Aerobiologia

ISSN 0944-2952, 1994

Atmospheric Chemistry and Physics, 2018

Elem Sci Anth, 2015

Experiment (HOPE 2000): Measurements and photostationary state calculations of