Adolf Ebel

University of Cologne | UOC · Institute of Geophysics and Meteorology

Air pollution is bad for human health and an international problem which is far from being solved. A large portion of the total PM10 and NO2 burden at, e.g., a street canyon, comes from background concentration. To analyse the origin of these background concentrations, simulations for PM10, PM2.5, and NO2 have been performed with the chemical trans...

Definition of elementary objects in the universe. Quantitative determination of accelerating expansion, equalling the increase of the speed of light. Time dependence of mass and the gravitational constant..

Air quality within the European Union (EU) is controlled by the Member States' monitoring networks. In this study, measured data is compared with the EURAD (EURopean Air pollution Dispersion) model system diagnostic output. Simulations for the German state North Rhine-Westphalia (NRW) with a horizontal grid resolution of 5 km × 5 km are analyzed. T...

Collection of manuscripts on the theory of universal systems by Helmut Zschoerner (in German). Application to new physics and cosmology. Ref.: http://kups.ub.uni-koeln.de/id/eprint/5214

Assessment of harmful impacts and risks of air pollution in case of accidents as well as of long lasting exposition is an important challenge of chemical transport modeling. Sad confirmation of this statement unexpectedly has come from the nuclear power plant accident in Fukushima which occurred while this paper was finalized. Two strategies to com...

The chemistry transport model system EURAD-IM and its variational data assimilation module are applied to assess air quality conditions during the measurement campaign VERTIKO. The inverse modelling system has been designed to run in a nested setup, assimilating in-situ observations and measurements by remote sensing. The benefits of joint initial...

The EURAD-IM chemistry transport model and its 4d-var inverse model extension is applied to one summer and one winter episode, in order to identify the benefit of tropospheric NO2 column retrievals for estimating near-surface nitrogen dioxide concentrations. Initial values and emission rates are jointly optimised by assimilating tropospheric NO2 da...

A thermodynamic model of the system H(+)-NH₄(+)-Na(+)-SO₄²⁻-NO₃⁻-Cl⁻-H₂O is parametrized and used to represent activity coefficients, equilibrium partial pressures of H₂O, HNO₃, HCl, H₂SO₄, and NH₃, and saturation with respect to 26 solid phases (NaCl(s), NaCl·2H₂O(s), Na₂SO₄(s), Na₂SO₄·10H₂O(s), NaNO₃·Na₂SO₄·H₂O(s), Na₃H(SO₄)₂(s), NaHSO₄(s), NaHSO...

Reduction of total NOx-emissions is one of the major objectives of the current European legislative standards in particular with respect to road traffic. Air quality regulations as formulated in the air quality directive 2008/50/EC however are aiming on NO2 and not on total NOx (NO+NO2). With respect to NO2-concentrations two limit values have to b...

Provided that the mean zonal and meridional wind components are known the average vertical velocity component and the momentum and heat sources of the mean meridional circulation can be evaluated applying the steady state equations of the forced mean circulation. Monthly meridional cross sections of pressure, temperature and wind given by Groves (1...

Indices, which reflect variations of the zonal geostrophic wind at the 10-mb-surface of the northern hemisphere, are compared with solar activity fluctuations applying methods of statistical frequency analysis. At a frequency corresponding to half the synodic rotation period of the sun, a significant response of the stratospheric circulation to sol...

The chemistry transport model system EURAD-IM and its variational data assimilation implementation are applied to air quality assessment problems. The facility of joint initial value and emission rate optimisation together with a nested 4d-var module is employed to the measurement campaign BERLIOZ. To emphasise the benefits of computationally effi...

Transport of atmospheric trace gases during a blocking event in the troposphere and lower stratosphere (UTLS) in August 1997 is studied. Considering the frequency of such events it is obvious that they play a significant role for climate and air chemistry and thus the atmospheric environment. The event has been selected because a unique set of comp...

available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/ecolmodel Editorial Large scale computations in environmental modelling: Editorial introduction Environmental problems are becoming more and more impor�tant for the modern society, and their importance will certainly be increased in the near future. High pollution levels (...

Ozone, water vapour and CFC 11 observations carried out with the CRISTA instrument from 8 to 16 August 1997 offered a unique opportunity to analyse the behaviour of a pronounced omega blocking event over the eastern North Atlantic and Europe with respect to transport of minor constituents in the UTLS. A regional chemistry transport model (EURAD) ne...

The EU directive 1999/30 allow for air quality modelling as a tool to plan strategies for air pollution reduction in Europe. A comprehensive air quality model, including ozone, NO2 and atmospheric particle (PM10) is applied to estimate the future development of air quality in Europe. As a base year 2002 is selected, model calculations are performed...

The role of perturbations of reactive trace gas concentration distributions in turbulent flows in the planetary boundary layer (PBL) is discussed. The paper focuses on disturbances with larger spatial scales. Sequential nesting of a chemical transport model is applied to assess the effect of neglecting subgrid chemical perturbations on the formatio...

The role of perturbations of reactive trace gas concentration distributions in turbulent flows in the planetary boundary layer (PBL) is discussed. The paper focuses on disturbances with larger spatial scales. Sequential nesting of a chemical transport model is applied to assess the effect of neglecting subgrid chemical perturbations on the formatio...

The temporal evolution of thermal convection in stress-free, base-heated boxes is investigated by means of a finite-element model. It is shown that the aspect ratio and also the initial conditions have a tremendous influence on the evolution. In boxes of aspect ratio A, significantly greater than unity (1.8<λ<3), the onset of time-dependence occurs...

The need of (i) more powerful computers, (ii) faster and more robust numerical methods and (iii) better utilization of the computer memory were considered in Working Group 3. Also different types of tasks, which require increased computer power for environmental risk and impact assessment, were considered during the discussion. The major conclusion...

Long-term simulations of atmospheric pollutants containing aerosols as an essential component may conveniently be used to support the assessment of the role of suspended particulate matter for the atmospheric environment on various temporal and spatial scales. They can help to bridge gaps of our knowledge and thus to broaden the range of applicatio...

In this paper some environmental problems resulting from oil spillage along oil pipeline routes are discussed. Oil penetration into soil with flat surface containing pits is studied by numerical modelling. Some analytical and numerical solutions of the diffusion and filtration equations are given and analyzed.

The demand for integrated modelling of different environmental compartments is increasing. With steadily growing computational power it seems possible to overcome the obstacles still preventing the comprehensive numerical treatment of the environmental system including society and economy. This article deals with approaches to the combined treatmen...

Application of tropospheric chemical transport models (CTMs) to chemical weather forecast on the global and regional scale is growing. In this paper advances and problems of numerical forecasts with Eulerian regional models are treated. After reviewing the progress of computer performance since the appearance of first complex CTMs, selected models...

Nearly global measurements of CFC 11 (CFCl3) in the upper troposphere and stratosphere are presented. Data are from the CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA 2) experiment in August 1997. They are the first global CFC 11 data set that covers the altitude regime 8 km to 28 km. A new temperature data product was d...

Numerical simulations of aerosols in the atmospheric boundary can computationally be highly demanding since processes governing the formation and dynamics of atmospheric particles are extremely complex. It is necessary to apply reasonable simplifications to make the computations tractable. This paper gives an outline of the approach to the problem...

Discussions were scheduled within the program of the NATO Advanced Research Workshop on “Advances in Air Pollution Modelling for Environmental Security”. Three major topics were discussed: (a) the use of more powerful computers in the treatment of some large-scale environmental models, (b) the application of data assimilation techniques for improvi...

Experiences having resulted from the development and application of a specific air quality modelling system (EURAD) are discussed. Reasons for complex modelling and motivations evolving from a quickly growing field of atmospheric science are presented. It is argued that meteorology and atmospheric chemistry form an integral interdependent system of...

A regional chemical transport model system (EURAD: European Air Pollution Dispersion model system) has been used to analyse peculiar features and improvements of air quality simulations using the method of subsequent model nesting. An episode with enhanced production of photo-oxidants in July 1994 in Central Europe is mainly studied. Effects of inc...

Global measurements of H_2O, CFC11 and O_3 in the lower stratosphere/upper troposphere have been performed during the second CRISTA flight in August 1997. These data are assimilated with the NCAR ROSE model, and meridional diffusive fluxes are calculated. In the southern winter hemisphere zero fluxes are found at latitudes corresponding to the loca...

We report first global measurements of CFC11 (CCl_3F) in the upper troposphere / lower stratosphere with high spatial resolution as measured by the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA--2) experiment in August 1997. An improved retrieval method combining CRISTA data and temperatures from the U.K. Meteorological...

A regional model system for the simulation of air quality in Europe (EURAD) has been employed for long-term calculations of atmospheric pollutants on different scales. The model allows sequential nesting. Starting with a domain covering most of Europe, the nesting procedure was used to scale down the simulations to a highly populated and industrial...

The development and application of numerical regional and local chemistry trans-port models (CTMs) is discussed. Introductory remarks address the motivation for the employment of these models in atmospheric and environmental science. Further-more, it is stated that there is a strong need for application of CTMs to environmental policy and planning...

As the previous chapter has indicated, significant improvements in the quantification of emissions could be made through the improvement of emission factors in various areas. The next focus of the GENEMIS work was on evaluation of emission data, in particular to assess uncertainties of data and methods and to validate and verify emissions. In the f...

The central purpose and scientific focus of GLOREAM, which stands for GLObal and REgional Atmospheric Modelling, was the investigation — by means of advanced and integrated modelling — of the processes and phenomena which determine the chemical composition of the troposphere over Europe and on a global scale. An essential part of GLOREAM has been t...

High resolution satellite data and (global and regional scale) modelling are combined within the AFO200 project TRACHT (Transport and Chemistry of the Tropopause Region) to study the dynamical and chemical processes in the upper troposphere/lower stratosphere. For the period of the 2nd flight of the CRISTA instrument in August 1997 the global scale...

The EURAD modeling system has been applied to calculate particulate matter and photo-oxidants in the troposphere over Europe for the year 1997. The numerical simulations are performed on a mother domain covering the whole of Europe (horizontal grid size 125 km) and three nest levels with grid sizes of 25, 5, and 1 km, respectively. The focus of the...

The modelling subproject GLOREAM was the successor of the EUROTRAC, first phase, subprojects EUMAC - European Modelling of Atmospheric Constituents - and GLOMAC - GLObal Modelling of Atmospheric Chemistry. In EUMAC the focus had been on the development of an advanced model hierarchy for air pollution dispersion simulations. The central model was th...

Summary A real-time forecast system for atmospheric pollutants is presented. The forecast system is based on the EURAD Model (European Air Pollution Dispersion Model). The daily updated forecast of atmospheric constituents for Europe, Central Europe and the German State of Northrhine-Westfalia was tested and is quasi operational since June 2001. Th...

Summary The European Air Pollution Dispersion Model EURAD has been used to calculate the concentration and deposition of air pollutants for several episodes of specific interest. The paper focus on nesting applications for Berlin (first intensive measurement campaign during the Berlin Ozone Experiment (BERLIOZ)) and the Federal State of North Rhine...

Comprehensive 3D-mesoscale atmospheric models have the ambitious, more or less unreachable goal to represent all relevant processes and all relevant input data which control the temporal evolution of 3D distributions of atmospheric constituents. For the regional-scale input data as landuse, emissions of gases and particles (including there composit...

During recent years the interest in long-term applications of air pollution modeling systems (AQMS) has strongly increased. Most of these models have been developed for the application to photo-oxidant episodes during the last decade. In this contribu- tion a long-term application of the EURAD modeling sytem to the year 1997 is pre- sented. Atmosph...

Advanced data assimilation can be applied to retrieve as much information as possible from photooxidant measurements in the trophosphere in order to analyze the chemical state. Traditional assimilation methods have proved to be unsatisfactory due to their inability (i) to account for locally varying chemical scenarios, (ii) to exploit informations...

High resolution modeling of air pollution events requires nested models. CARLOS is a combination of two comprehensive air quality simulation models that calculate chemistry and transport on regional and local scales. Both models apply nesting techniques to describe the influx of tracers into the inner highly resolved modeling domain. High resolutio...

The Secondary Organic Aerosol Model (SORGAM) has-been developed for use in comprehensive air quality model systems. Coupled to a chemistry-transport model, SORGAM is capable of simulating secondary organic aerosol (SOA) formation including the production of low-volatility products and their subsequent gas/particle partitioning. The current model fo...

The sensitivity of modelled ozone depletion in the winter Arctic stratosphere to different assumptions of prevalent PSC types and PSC formation mechanisms is investigated. Three-dimensional simulations of the winter 1995/96 are performed with the COlogne Model of the Middle Atmosphere (COMMA) by applying different PSC microphysical schemes. Model r...

Principal considerations about the evaluation of meso-scale chemistry-transport models are presented exploiting and commenting a concept which was developed in the framework of the German tropospheric research programme TFS. Specific experiences resulting from the application of the concept are described. Aspects of reliability of numerical simulat...

Ozone is the most important environmental atmospheric pollutant in Europe during summer time. It is photochemically formed from anthropogenic emissions (mainly traffic) and from biogenic emissions of nitrogen oxides (NOx) and hydrocarbons (NMVOC) under clear sky and high radiation conditions. Since high ozone values may cause health problems and ma...

Airmass flux across the tropopause modifies the budget of chemically reactive minor constituents in the stratosphere and the troposphere. Flux estimates reported in the literature exhibit large discrepancies, mainly due to the application of different estimation algorithms and examination of different episodes. The different studies also focus on d...

The model system CARLOS (Chemistry and Atmospheric transport in Regional and LOcal Scale) has been developed with the aim to simulate atmospheric transport and air chemistry on local scales taking into account the influence of large-scale transport. The system has been applied to a photochemical smog episode in summer 1997. Multiple nested simulati...

The problem of analyzing the chemical state of the troposphere and the associated emission scenario on the basis of observations and model simulations is considered. The method applied is the four-dimensional variational data assimilation method (4D-var) which iteratively minimizes the misfit between modeled concentration levels and measurements. T...

The role of inorganic bromine compounds in the chemistry of the midlatitude lowermost stratosphere is examined. Model studies are performed using a chemistry box model. Special emphasis is layed on investigating the implications of bromine chemistry on the atmospheric effects of subsonic aircraft NOx emissions. The simulations suggest that the pres...

Although the first studies on cloud chemistry date back to the nineteen fifties, it was only at the beginning of the eighties that the key role played by clouds in tropospheric chemistry was clearly highlighted. Some fundamental papers then pointed out the overall effect on the cloud life cycle, of the incorporation of chemical components within cl...

Chemical transfer and transport modelling of atmospheric constituents in EUROTRAC has been applied to numerous processes and phenomena covering a large range of scales from local to global. The EUROTRAC subprojects GLOMAC (Global Modelling of Atmospheric Chemistry) and EUMAC (European Modelling of Atmospheric Constituent) were exclusively devoted t...

Die schnell fortschreitende Entwicklung von leistungsfähigen Computern — von den Großrechnern hinab bis zu den Workstations und PCs (d.h. Personal Computern) — hat die Entwicklung von numerischen Modellen für die Simulation von luftchemischen Prozessen und dem Spurenstofftransport in den letzten beiden Jahrzehnten stark begünstigt. Damit ist es mög...

Die Atmosphäre wird in diesem Kapitel vor allem aus der Perspektive des Transports von Luftmassen und deren Eigenschaften betrachtet. Man hat zwischen physikalischen und chemischen Eigenschaften der Luft zu unterscheiden, die durch Zustandsgrößen wie Temperatur oder Wind auf der einen Seite und Konzentrationen oder Mischungsverhältnissen auf der an...

The EURAD modelling system has been used to simulate transport, chemical transformation and deposition of air pollutants in Europe [1–3]. The physical and chemical processes to describe the formation of photo-oxidants and the production of acidity are included in the modelling system. Meteorological fields are calculated by application of the NCAR/...

Presents the development and implementation of a four-dimensional variational (4D-var) data assimilation technique for a comprehensive Eulerian chemistry-transport model. The method aims at analysing the chemical state of the atmosphere on the basis of trace gas observations with arbitrary distribution in time and space, a chemistry-transport model...

The impact of a future emission scenario is studied with emphasis on secondary organic aerosol formation due to changes in precursor VOC emissions. For this purpose, a reference episode in July 1994 is simulated. An emission trend scenario for the year 2000 will be performed and the results will be analyzed, focusing on the changes of SOA concentra...

A new version of MADE is suitable for studying the effects of clouds on the aerosol size distribution and the gas phase concentration. Using meteorological and chemical input fields, MADE provides adequate informations on the aerosol size distribution and chemical composition.

A model is presented to simulate heterogeneous reactions of nitrogen, chlorine, and bromine compounds on and in sulfate aerosols under conditions encountered in the lowermost stratosphere and upper troposphere. Box model calculations were performed to investigate the impact of these heterogeneous reactions on the chemistry of the midlatitude tropop...

Traffic and air quality as aims of the FVU are interconnected and interdisciplinary. CARLOS is a combination of two comprehensive air quality simulation models to calculate chemistry and transport in regional and local scales. Both models apply nesting techniques to describe the influx into the modeling domain. High resolution emission inventories...

The problem of exploiting observations scattered in time for the analysis of the state of the atmosphere is considered in meteorology for initial value determination since the mid—eighties (e.g. [7]). While there is now a growing literature on that subject in meteorology and oceanography, applications in atmospheric chemistry data assimilation are...

In the Wuppertal area, Germany, air pollution due to the emission of vehicles is calculated for two summer smog episodes in 1996 and 1997 using a coupled system of atmospheric models that are applicable to different scales. The model system CARLOS (Chemistry and Atmospheric transport in Regional and Local Scale) contains complex subsystems for simu...

On the basis of a coupled 3d-model of the dynamics and chemistry of the mesosphere-lower thermosphere (30 to 150 km) the global distribution of the main plasma components (79 to 128 km) has been calculated. A small selection of results obtained from different model experiments is presented.

The Modal Aerosol Dynamics model for Europe (MADE) has been developed as an extension to mesoscale chemistry transport models to allow a more detailed treatment of aerosol effects in these models. Due to the complexity of the atmospheric aerosol system an approach has been chosen which is, on the one hand, fast enough for this application and, on t...

The Modal Aerosol Dynamics model for Europe (MADE) has been developed as an extension to mesoscale chemistry transport models to allow a more detailed treatment of aerosol effects in these models. Due to the complexity of the atmospheric aerosol system an approach has been chosen which is, on the one hand, fast enough for this application and, on t...

A global three-dimensional model of the dynamics and chemistry of the mesosphere—lower thermosphere region (30–150 km) has been developed. This model is used to calculate the distributions of the most important minor and plasma constituents. Additionally, the mass fluxes of those constituents subjected to transport and the chemical heating rates ha...

A box model representative for a mesoscale volume and three different plume models are used to estimate the chemical conversion of exhaust species of a subsonic aircraft at cruise altitude. Clearly deviating results have been obtained for instantaneous mixing of the exhaust in a box and gradual dispersion of a plume. The effect of varying daytime o...

A global ECMWF data set comprising ten years of daily routine T63 analyses is employed for the derivation of regional and temporal tropopause fold statistics. Due to the small scale of folds relative to grid resolution it was found to be convenient to identify them by joint occurrences of potential vorticity maxima and upper tropospheric Q-vector d...

The European Air Pollution Dispersion model system (EURAD) was developed to simulate air pollution episodes in Europe. With nesting capability, the model was applied to different problems of emission effects and air quality control, including VOC and NOx emissions reduction, and evaluation of the photochemical ozone creation potential (POCP) of ant...

The initialisation and the treatment of the boundary conditions of a mesoscale chemistry-transport-model, covering a limited area, are of great importance. The choice of the initial and boundary values can significantly influence the results of a simulation, so that they should be determined as well as possible (NAPAP, 1991). For this reason it is...

The particulate matter suspended in the atmosphere is strongly linked to numerous air pollution problems. These include the -direct and indirect- influences on the radiative budget of the atmosphere, the potential for adverse health effects, the influence of particles on the long-range transport of air pollutants and the interaction of aerosol part...

On the basis of a coupled 3d-model of the dynamics and chemistry of the mesosphere (30–150 km) the global distribution of the most relevant minor constituents has been calculated. A selection of results obtained in particular for oxygen and related chemical heating rates from different model experiments is presented.

This paper gives a synthesis of three algorithms to detect the presenceof tropopause folds from vertical ozone/radio-sounding profiles and frommeteorological analysis. Also an algorithm to identify injection ofstratospheric air into the lower troposphere fromozone/7beryllium time series is presented. Differences in theresults obtained from the algo...

Results from two air quality models (LOTOS, EURAD) have been used toanalyse the contribution of the different terms in the continuity equationto the budget of ozone, NOx and PAN. Both models cover largeparts of Europe and describe the processes relevant for troposphericchemistry and dynamics. One of the models is designed to simulate episodesin the...

A statistical assessment of deep intrusions of stratospheric air based on records of two adjacent mountain stations of the northern Alps at different altitudes is presented. Ten years recordings of beryllium activity, ozone concentrations, and relative humidity at the Zugspitze summit (2962 m a.s.l.), as well as ozone and relative humidity at the W...

The EUROTRAC subproject EUMAC (European Modelling of Atmospheric Constituents) continued its work on the development of an advanced model hierarchy for air pollution dispersion simulations. The applicability of the long-range transport model system EURAD (European Air Pollution Dispersion Model System) to episodic simulations has been demonstrated...

The method of variational adjoint data assimilation has been applied to assimilate chemistry observations into a comprehensive tropospheric gas phase model. The rationale of this method is to find the correct initial values for a subsequent atmospheric chemistry model run when observations scattered in time are available. The variational adjoint te...

The importance of exchange processes between the atmospheric boundary layer and the free troposphere on the boundary layer ozone budget was studied by data analysis and model simulations. The current results indicate that, even over continental Europe, large-scale synoptically induced vertical motions are more important to the low level ozone budge...

The principal goal of the project EURAD has been to contribute to this understanding through the development and application of a regional model system consistently treating chemistry and dynamics of the atmosphere as well as anthropogenic and biogenic emissions. At present, the EURAD system is mainly applied to regional simulation of episodes of a...