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Wer verschmutzt wessen Luft in Europa? Schadstofftransport in der Atmosph�re
A state-of-the-art gas phase chemical mechanism for modeling atmospheric chemistry on a regional scale is presented. The second generation Regional acid Deposition Model (RADM2) gas phase chemical mechanism, like its predecessor RADM1, is highly nonlinear, since predicted ozone, sulfate, nitric acid and hydrogen peroxide concentrations are complicated functions of NOx and nonmethane hydrocarbon concentrations. The RADM2 chemical mechanism is an upgrade of RADM1 in that (1) three classes of higher alkanes are used instead of one, (2) a more detailed treatment of aromatic chemistry is used, (3) the two higher alkene classes now represent internal and terminal alkenes, (4) ketones and dicarbonyl species are treated as classes distinct from aldehydes, (5) isoprene is now included as an explicit species, and (6) there is a more detailed treatment of peroxy radical-peroxy radical reactions. As a result of these improvements the RADM2 mechanism simulates the concentrations of peroxyacetyl nitrate, HNO3, and H2O2 under a wide variety of environmental conditions. Comparisons of RADM2 mechanism with the RADM1 mechanism predictions and selected environmental chamber experimental results indicate that for typical atmospheric conditions, both mechanisms reliably predict O3, sulfate and nitric acid concentrations. The RADM2 mechanism gives lower and presumably more realistic predictions of H2O2 because of its more detailed treatment of peroxy radical-peroxy radical reactions.
We have developed a three-dimensional Eulerian regional acid deposition model to calculate episodic chemical concentrations and dry and wet deposition of acids in North America. This transport, transformation, and deposition modeling system subdivides the troposphere over the eastern United States, southeastern Canada, and the western Atlantic Ocean into a six-level, 30 by 30 horizontal grid with a horizontal grid size of 80 x 80 km/sup 2/. Transport and vertical diffusion of 24 trace gases and particles are calculated using temporally and spatially varying meteorology, provided by a mesoscale meteorological model. A gas phase chemical reaction mechanism is used to simulate concentrations and chemical conversion rates for 36 species, including 14 stable organics and 11 short-lived radicals. Altitude-, latitude-, and season-dependent photolysis rates for nine reactions in the chemical mechanism are specified using a delta-Eddington radiative transfer model which includes O/sub 2/ and O/sub 3/ absorption, scattering and absorption by clouds and aerosols, Rayleigh scattering, and ground relections.
Emissions from aircraft engines include
carbon dioxide, water vapour, nitrogen oxides, sulphur components and various
other gases and particles. Such emissions from high-flying global civil subsonic
air traffic may cause anthropogenic climate changes by an increase of ozone and
cloudiness in the upper troposphere, and by an enhanced greenhouse effect. The
absolute emissions by air traffic are small (a few percent of the total)
compared to surface emissions. However, the greenhouse effect of emitted water
and of nitrogen oxides at cruise altitude is potentially large compared to that
of the same emissions near the earth's surface because of relatively large
residence times at flight altitudes, low background concentrations, low
temperature, and large radiative efficiency. Model computations indicate that
emission of nitrogen oxides has doubled the background concentration in the
upper troposphere between 40°N and 60°N. Models also indicate that this causes
an increase of ozone by about 5-20%. Regionally, the observed annual mean change
in cloudiness is 0.4%. It is estimated that the resultant greenhouse effect of
changes in ozone and thin cirrus cloud cover causes a climatic surface
temperature change of 0.01-0.1 K. These temperature changes are small compared
to the natural variability. Recent research indicates that the emissions at
cruise altitude may increase the amount of stratospheric aerosols and polar
stratospheric clouds and thereby have an impact on the atmospheric environment.
Air traffic is increasing about 5-6% per year, fuel consumption by about 3%,
hence the effects of the related emissions are expected to grow. This paper
surveys the state of knowledge and describes several results from recent and
ongoing research.
Der Gedanke, ein Buch zum Thema "Chemie und Umwelt" zu schreiben, ent stand aufgrund unserer Erfahrungen mit einem Seminar desselben Titels, das in den Wintersemestern 1987/88 und 1988/89 am Physikalisch-Chemischen Institut der Universität Heidelberg stattfand. Es zeigte sich, daß dieses Thema offenbar nicht nur für die Studierenden der Chemie,sondern auch für diejenigen verwand ter Fachrichtungen von größtem Interesse ist, es aber andererseits kaum Bücher gibt, die im Stil eines Lehrbuches eine zusammenfassende, fachübergreifende In formation anbieten. Angesichts der immer bedrohlicher werdenden Auswirkungen von chemi schen Prozessen und Chemieprodukten auf unser Leben sollte es ein Gebot für die Lehrenden an einer Universität sein, den Studierenden bei ihrer naturwissen schaftlichen Ausbildung eine ebenso fachlich fundierte wie kritische Auseinan dersetzung mit dieser Problematik zu ermöglichen. Es ist selbstverständlich, daß nicht alles, was zum Thema "Chemie und Umwelt" gehört, in einem Buch des vor liegenden Umfangs behandelt werden kann. Die thematische Auswahl beschränkt sich auf den eigentlich schon sehr ausgedehnten Komplex der Schadstoffbelastung von Luft, Wasser und Boden, der die wichtigsten umweltrelevanten Themenbe reiche umfaßt. Der Problemkreis Kerntechnik und radioaktive Belastung wurde bewußt ausgeklammert, da seine angemessene Behandlung den Rahmen dieses Buches gesprengt hätte.
Daß Fremdstoffe durch Deposition am Erdboden und an der Vegetation aus verunreinigter Luft entfernt werden können, hat meteorologische Ursachen, die in erster Linie im spezifischen Verhalten der an die Erdoberfläche angrenzenden Luftschicht von bis zu mehreren 100 m Mächtigkeit zu finden sind. Der materielle und energetische Einfluß des Bodens führt dazu, daß in dieser sog. atmosphärischen Grenzschicht Transportoder Austauschvermögen eine bedeutende Rolle spielt. Das physikalisch wichtigste merkmal der ABL ist nämlich ihre intensive turbulence Durchmischung, die zur sachgerechten Behandlung der ABL unbedingt berücksichtigt werden mubß. Eigenschaften wie thermische Stabilität, Baroklinität, impuls des Windes in Oberan Schichten, Mischungslängen Topografie- und Oberflächencharakteristika, sowie Transportwiderstände etc. bestimmen zusammen die Turbulenzparameter, die für den Transport und die Deposition von Fredstoffen in der ABL verantwothlich sind. Da die Umwelrprobleme durch Luftverunreinigung waschen, wird es zunehmend wichtiger, diese Effekte durch messungen und vor Allem rechnerische Modellverfahren zu erfassen.
Following the Chernobyl accident in 1986, the Atmospheric Transport Model Evaluation Study (ATMES) was initiated. Objectives were to provide a database for guidance and advice on models for government agencies; to indicate data requirements for model inputs and off-site monitoring; to provide information for scientists on models and how best to improve them. The twenty one participating models are presented here, all using common inputs for source data, meteorological and radiological data. Technical conclusions are described and elaborated and a list of findings and recommendations by the evaluation committee are presented. -R.Gower
Analysis of the available long-term ozone records of surface and ozonesonde observations from rural stations confirm the continuous increase of ozone concentration, by about 1% per year, during the last two decades. Although the data are very sparse and do not represent a global average, they reveal some interesting seasonal variations. It appears that the surface ozone during November-January is increasing at a greater rate than during May-October. This could be a confirmation to recent modelling studies highlighting the important combined effect of anthropogenic emissions and natural level of concentrations of NOx, non-methane hydrocarbons (NMHC), as well as CO and CH4, on the ozone production in the troposphere. The ozone in the upper part (500–300 hPa) of the troposphere usually shows a lower rate of increase than the ozone in the lower part (850–500 hPa). The monthly deviations from the mean of the lower stratospheric ozone compared with those of the surface ozone show some general concurrence of the shape of the long-term fluctuations, but also show some differences, which together with the opposite (by sign) trends of both series may indicate domination of processes affecting the surface ozone regime, other than solely the cross-tropopause transfer.
The book is aimed at the beginning graduate level for students with an undergraduate background in meteorology. The chapter organization is: mean boundary layer characteristics; statistics; application of the governing equations to turbulent flow; prognostic equations for turbulent fluxes and variances; turbulent kinetic energy, stability, and scaling; turbulence closure techniques; boundary conditions and external forcings; time series; similarity theory; measurement and simulation techniques; convective mixed layer; stable boundary layer; boundary layer clouds; geographic effects. -after Author
At first glance, the large number of equations developed in Chapters 3-5 would suggest that we have a fairly complete description of turbulent flow. Unfortunately, a closer examination reveals that there are a large number of unknowns remaining in those equations. These unknowns must be dealt with in order end up with a useful description of turbulence that can be applied to real situations. In this Chapter, the unknowns are identified, and methods to parameterize them are reviewed. Simulation techniques such as large-eddy simulation are discussed in Chapter 10.
This paper presents atmospheric sulfur and nitrogen budgets for the region of southeast Europe, including Albania, Bulgaria, Greece, Italy, Romania, the western part of th Anthropogenic and natural emission fluxes are estimated from information in the literature; wet and dry deposition fluxes are determined from both EMEP measurements and modelling results and the input and output terms are based on EMEP modelling results. For sulfur, the total inputs and outputs for the region range from 3.8 to 4.4 and 4.0 to 7.2 Tg Sy−1, respectively; for nitrogen, the inputs and outputs are 2.1 to 3.8 and 2.0 to 6.6 TgNy−1, respectively. On average, the nitrogen fluxes consist of approximately equal parts of oxidized and reduced forms. Despite the presence of strong upwind sources, anthropogenic emission within the region dominate the inputs, accounting for approximately 70% of the total inputs for both S and N. The three output terms, outflow, wet and dry de'position, are of similar magnitude for both species, but all have considerable uncertainties (ca 50%). The cycling of S and N in the atmosphere of southeast Europe has common features with that in eastern North America and west-central Europe, in that anthropogenic S and N dominate the natural cycles of these substances, anthropogenic emissions within the region significantly exceed inflows to the region, and the region is a net exporter of S and N species.
We describe the development of a general, predictive, hydrostatic meteorological model. The model is three-dimensional and is suitable for a wide variety of problems, ranging from the synoptic scale to the small end of the mesoscale. The model contains provisions for variable terrain, a moisture cycle, sensible heat addition at the earth's interface, and high- and low-resolution boundary layer physics. This paper presents the mathematical and numerical formulation used in the various options of the model. First we write the basic equations on a Lambert conformal projection. Then we describe the horizontal and vertical grid structure, the finite-difference equations, and the energetics of the three-dimensional model and its two-dimensional analog. We consider the role of the lateral boundary conditions for limited area forecasts, with emphasis on their effect on the mean motion over the domain. Two options for including the frictional and diabatic effects at the earth's surface are presented. Thes...
Dimethylsulfide (DMS) concentrations have been measured in over 1000
Pacific surface seawater samples during the past 4 years. The data have
been tabulated to take into account both regional and seasonal
variations in concentration. The area-weighted summer and winter
concentrations of DMS in the North Pacific Ocean are 2.2 and 1.3 nmol/L,
respectively. Wind speed, surface seawater temperature, and DMS
diffusivities are used to calculate air-sea exchange coefficients. The
area-weighted summer and winter DMS piston velocities are 2.3 and 2.7
m/d, respectively. These exchange coefficients combined with the
concentration data yield a net ocean to atmosphere DMS flux in the North
Pacific Ocean of 0.12 Tmol/yr. Extrapolating this calculation by
regional areas to the global ocean yields a net DMS flux of 0.50
Tmol/yr, less than earlier estimates of 1.2 Tmol/yr, but still
consistent with excess sulfate deposition estimates and model studies of
the marine atmospheric sulfur budget. The uncertainty in the flux
estimate is roughly a factor of 2.
Previous research has suggested that Whites' evaluations of Blacks who are presented positively or negatively tend to be more extreme than evaluations of similar White targets. In Study 1, White subjects rated a Black or White confederate who was responsible for success or failure at a joint task. There was a clear cross-race polarization of evaluations. Study 2 tested two possible explanations of the polarization phenomenon-the authors' ambivalence formulation and Linville and Jones's cognitive complexity hypothesis. As hypothesized, ambivalence was directly related to favorability of impression ratings in the success condition. In the failure condition, the correlation was in the predicted inverse direction but was not significant. The difference between the two correlations, as expected, was significant. No support was obtained for the cognitive complexity hypothesis. Rather, in the failure condition complexity was directly related to the unfavorability of ratings, contrary to the hypothesis.
A simple quasi-two-dimensional model is used to study the zonal distribution of NOx. The model includes vertical transport in the form of eddy diffusion and deep convection, zonal transport by a vertical uniform wind, and a simplified chemistry of NO, NO2, and HNO3. The NOx sources considered are surface emissions (mostly from the combustion of fossil fuel), lightning, aircraft emissions, and downward transport from the stratosphere. The model is applied to the latitude band of 40° and 50°N during the month of June; the contributions to the zonal NOx distribution from the individual sources and transport processes are investigated. The model predicted NOx concentration in the upper troposphere is dominated by air lofted from the polluted planetary boundary layer over the large industrial areas of eastern North America and Europe. Aircraft emissions are also important and contribute on average 30%. Stratospheric input is minor about 10%, less even than that by lightning. The model provides a clear indication of intercontinental transport of NOx and HNO3 in the upper troposphere. Comparison of the modeled NO profiles over the western Atlantic with those measured during STRATOZ III in 1984 shows good agreement at all altitudes.
There is growing evidence that ozone levels in the lower troposphere over the continents of the Northern Hemisphere have been increasing during the past decades1,2. Questions regarding pre-industrial or 'background' ozone concentrations have led to the search for data from the early days of ozone monitoring, during the second half of the last century. Unfortunately, most measurements were then made using Schönbein test paper, giving only semi-quantitative information due to poor standardization and the influence of humidity and wind speed on its sensitivity35. We have reinvesti-gated a set of ozone measurements gathered at the Observatoire de Montsouris, located on the outskirts of Paris, where a quantitative method was established in 18766 and used continuously for 34 years. The evaluation of the technique, together with the analysis of nearly 3,000 of the original daily measurements that previously remained unnoticed in a statistical bulletin of the City of Paris7, provides conclusive evidence that ozone levels in central Europe 100 years ago averaged 10 p.p.b. and exhibited a seasonal variation, with a maximum during the spring months. Comparisons with modern data show that ozone levels in rural areas have more than doubled over the past century and that the tropospheric ozone budget is now strongly influenced by photochemical production due to increased levels of NOx.
Emissions from aircraft engines include carbon dioxide, water vapour, nitrogen oxides, sulphur components and various other gases and particles. Such emissions from high-flying global civil subsonic air traffic may cause anthropogenic climate changes by an increase of ozone and cloudiness in the upper troposphere, and by an enhanced greenhouse effect. The absolute emissions by air traffic are small (a few percent of the total) compared to surface emissions. However, the greenhouse effect of emitted water and of nitrogen oxides at cruise altitude is potentially large compared to that of the same emissions near the earth's surface because of relatively large residence times at flight altitudes, low background concentrations, low temperature, and large radiative efficiency. Model computations indicate that emission of nitrogen oxides has doubled the background concentration in the upper troposphere between 40°N and 60°N. Models also indicate that this causes an increase of ozone by about 5-20%. Regionally, the observed annual mean change in cloudiness is 0.4%. It is estimated that the resultant greenhouse effect of changes in ozone and thin cirrus cloud cover causes a climatic surface temperature change of 0.01-0.1 K. These temperature changes are small compared to the natural variability. Recent research indicates that the emissions at cruise altitude may increase the amount of stratospheric aerosols and polar stratospheric clouds and thereby have an impact on the atmospheric environment. Air traffic is increasing about 5-6% per year, fuel consumption by about 3%, hence the effects of the related emissions are expected to grow. This paper surveys the state of knowledge and describes several results from recent and ongoing research.
The opean cid eposition Model (EURAD) is used to investigate the long-range transport (LRT) and deposition of radioactive material in Europe during the first week after the Chernobyl accident. Emphasis is laid on using the model system in a forecast mode as possibly would be done shortly after such an event. Thus, meteorological fields are predicted with the PSU/NCAR mososcale model MM4. The multilayer Eulerian model CTM (hemistry ransport ) is applied to compute transport and deposition of Cs-137 and I-131 using the predicted meteorological fields. However, the accident scenario was estimated using published data. The model results and performance are discussed by comparison with observations. It is demonstrated that the model can reproduce certain observed characteristics of the radioactive cloud, i.e. trends in surface air concentrations, arrival times and wet deposition patterns. This leads to the suggestion that the predictive capability of the EURAD-system has a relatively high level considering the fact that several simple approaches were used.
A chemical mechanism for the EPA/NCAR regional acid deposition model has been created by simplifying state-of-the-art chemical mechanisms. The RAD M mechanism models smog chamber data to a reasonable level of performance. The RADM mechanism, the carbon bond mechanism of Whitten et al. (1985, U.S. EPA Contract No. 68-02-3735), and the explicit mechanism of Leone and Seinfeld (1985, Atmospheric Environment19, 437–464) give SO2 and nitrogen oxide oxidation rates which are in good agreement. The importance of Criegee intermediates for the oxidation of SO2 varies between the different mechanisms, and Criegee intermediates are much more important in the carbon bond mechanism. There is considerable variation in the predicted amounts of hydrogen peroxide among all three mechanisms. More data such as HO2 and H2O2 concentration measurements from laboratory studies, smog chambers and field data will be required before chemical mechanisms for regional acid deposition modeling can be thoroughly tested.
The individual involvement of 69 hydrocarbons in photochemical ozone and PAN formation in Europe is examined using the Harwell photochemical trajectory model. A detailed chemical scheme has been built up involving 384 chemical species and 684 chemical reactions to describe formation of ozone and other photochemically-generated secondary pollutants. Trajectories across the southern British Isles, from the F.R.G. to the Republic of Ireland, and from France to Sweden have been studies. The concept of a photochemical ozone creating potential, POCP, has been developed to assist in the understanding of the role of each individual hydrocarbon. The POCP value for a given hydrocarbon assesses its ability to form ozone relative to ethylene for an identical atmospheric mass emission. The concept has been extended to PAN formation so that the assessment of the likely impact of control policies can be extended to a wider range of secondary pollutants other than ozone.
Emotion-specific activity in the autonomic nervous system was generated by constructing facial prototypes of emotion muscle
by muscle and by reliving past emotional experiences. The autonomic activity produced distinguished not only between positive
and negative emotions, but also among negative emotions. This finding challenges emotion theories that have proposed autonomic
activity to be undifferentiated or that have failed to address the implications of autonomic differentiation in emotion.
Imaging the interior of living bodies with light may assist in the diagnosis and treatment of a number of clinical problems, which include the early detection of tumors and hypoxic cerebral injury. An existing picosecond time-of-flight and absorbance (TOFA) optical system has been used to image a model biologic system and a rat. Model measurements confirmed TOFA principles in systems with a high degree of photon scattering; rat images, which were constructed from the variable time delays experienced by a fixed fraction of early-arriving transmitted photons, revealed identifiable internal structure. A combination of light-based quantitative measurement and TOFA localization may have applications in continuous, noninvasive monitoring for structural imaging and spatial chemometric analysis in humans.
Measurement of the levels of ozone and carbon monoxide (a tracer of anthropogenic pollution) at three surface sites on the Atlantic coast of Canada allow the estimation of the amount of ozone photochemically produced from anthropogenic precursors over North America and transported to the lower troposphere over the temperate North Atlantic Ocean. This amount is greater than that injected from the stratosphere, the primary natural source of ozone. This conclusion supports the contention that ozone derived from anthropogenic pollution has a hemisphere-wide effect at northern temperate latitudes.
Dimethyl sulfide (DMS) has been identified as the major volatile sulfur compound in 628 samples of surface seawater representing
most of the major oceanic ecozones. In at least three respects, its vertical distribution, its local patchiness, and its distribution
in oceanic ecozones, the concentration of DMS in the sea exhibits a pattern similar to that of primary production. The global
weightedaverage concentration of DMS in surface seawater is 102 nanograms of sulfur (DMS) per liter, corresponding to a global
sea-to-air flux of 39 x 1012 grams of sulfur per year. When the biogenic sulfur contributions from the land surface are added, the biogenic sulfur gas
flux is approximately equal to the anthropogenic flux of sulfur dioxide. The DMS concentration in air over the equatorial
Pacific varies diurnally between 120 and 200 nanograms of sulfur (DMS) per cubic meter, in agreement with the predictions
of photochemical models. The estimated source flux of DMS from the oceans to the marine atmosphere is in agreement with independently
obtained estimates of the removal fluxes of DMS and its oxidation products from the atmosphere.
On the effect of emissions from aircraft en-gines on the state of the atmosphere. Paper, AGARD, 81st Symposium on Fuels and Combustion Technology for Ad-vanced Aircraft Engines Lokale und regionale Ozonpro-duktion: Chemie und Transport
- U Schumann
Schumann, U.: On the effect of emissions from aircraft en-gines on the state of the atmosphere. Paper, AGARD, 81st Symposium on Fuels and Combustion Technology for Ad-vanced Aircraft Engines, Colleferro 1993 41. GeiB, H., Volz-Thomas, A.: Lokale und regionale Ozonpro-duktion: Chemie und Transport. Abschlul3bericht zum BMFT-Vorhaben 07EU7235, Forschungszentrum J(ilich, ICG2 (1992)
SANA. Wissenschaftliches Begleitprogramm zur Sanierung der Atmosphgre in den neuen Bundesl~indern. BMFT, Bonn 1992 11
- W Seiler
Seiler, W.: SANA. Wissenschaftliches Begleitprogramm zur Sanierung der Atmosphgre in den neuen Bundesl~indern. BMFT, Bonn 1992 11. Landesanstalt fiir Immissionsschutz Nordrhein-Westfalen: Berichte fiber die Luftqualitfit in Nordrhein-Westfalen, TEMES-Jahresbericht 1991, Kontinuierliche telemetrische Luftqualit~itsmessungen. Essen 1992
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in: Tropospheric Ozone
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Schöpp, W: A Model to Calculate Natural VOC Emissions from Forests in Europe
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The Athens experiment
- N Moussiopoulos
- N. Moussiopoulos
The LOTOS Long-Term Ozone Simulation Project
- P J H Builtjes
Calculated Budgets for Airborne Acidifying Components in Europe
- T Iverson
- N E Halvorsen
- S Mylona
- H Sandnes
European Inventory of Emissions of Pollutants into the Atmosphere
- R Bouscaren
Description of the EUROTRAC Subproject GENEMIS
- R Friedrich
Lokale und regionale Ozonproduktion: Chemie und Transport
- H Geiß
- A Volzthomas
NCAR/PSU Mesoscale Model (MM4), User's manual. The EURAD Version of MM4
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Airborne Transboundary Transport of Sulphur and Nitrogen over Europe - Model Description and Calculations
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- H Sandnes
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- Ø Hov
in: Atmosphärische Spurenstoffe und ihr physikalisch-chemisches Verhalten
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Summary Report from the Chemical Co-ordinating Centre for the Third Phase of EMEP
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Ammonia Emissions in Europe: Updated Emission and Emission Variations
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User's manual. The EURAD Version of MM4
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