!! All these subprojects finished at the end of 1995 !!
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
High Alpine Aerosol and Snow Chemistry Study (ALPTRAC): study of the deposition of acidity and aerosols in the ecologically sensitive high Alpine regions.
Coordinator: Dietmar Wagenbach (University of Heidelberg)
Objectives:
Highlights of ALPTRAC current scientific results
Snow samples are now routinely taken at 15 sites between 2450 and 3900 m over a 650 km stretch of the Alps. There is clear evidence for an increase in acid deposition, both sulphuric and nitric acids, over the Alps this century, with a striking increase, west to east, by a factor of between 2 and 3. ( Although this increase may be due to greater deposition in the east, a possible dilution effect in the west, where more snow fell, needs to be taken into account.) A complete description of the stations and their activities is published in the ALPTRAC Data Catalogue, a EUROTRAC Special Publication.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Soren Larsen (Riso National Laboratory, Roskilde)
Deputy: Michael Schulz (University of Hamburg)
Scientific aims:
Highlights of the scientific results
Studies within ASE are yielding information on the dry deposition of trace substances to north European seas. Results include improved estimates of the atmospheric load of nitrogen compounds and sulphur to the North Sea and the inner Danish waters. Corresponding estimates for trace metals are also available.
Emission of biogenic gases from the seas
The ASE activities on biogenic gas emissions have concentrated on the mechanisms behind the emission rates of hydrocarbons, dimethyl sulphide (DMS) and other organo-sulphur compounds in the European seas (North Sea, western Mediterranean) as well as the upstream Atlantic Ocean. A better description of the geographical distribution of these emissions has been obtained, and a strong correlation between the air concentration of DMS and the concentrations of cloud concentration nuclei (CCN) has been found for the clean Atlantic air but not for air masses of continental origin.
The North Sea Experiment
A major campaign for ten ASE groups, studying the chemical composition of aerosols, was the North Sea Experiment in September 1991, involving two research vessels and several coastal stations. The two ships sailed on a circle with one always 200 km upwind of the other, so that changes in pollutant concentrations could be measured as the boundary layer air masses crossed the sea. One result showed that the concentration of nitrogen dioxide, N02, decreased appreciably over the sea where there are no new sources. During the daytime N02 is lost by the reaction with OH radicals, and at night, the reaction with ozone leads to the formation of nitric acid.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Sjaak Slanina (ECN, Petten)
Deputy: David Fowler (ITE, Edinburgh)
Scientific aims:
Highlights of the scientific results
Several field campaigns have been organised within BIATEX, the largest EUROTRAC subproject involving 41 groups from 15 countries.
The results are being evaluated in order to produce maps of the biogenic emission Of S02, oxidised and reduced nitrogen and for the emission of volatile organic compounds (VOCs) in Europe.
List of BIATEX publications
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Adolf Ebel (University of Cologne)
Deputy: Nicolas Moussiopoulos (University of Thessaloniki)
Scientific aims:
Model for studying pollutant episodes
The core computer programme for the modelling of atmospheric pollution over Europe is EURAD, a mesoscale model. It is a three dimensional Eulerian model with a flexible horizontal grid and is already being used for practical applications, such as the effect of emission reductions on ozone concentrations. Various sections of it, however, are being developed to incorporate better representations of cloud transport and chemical processes, boundary layer effects, the effect of pollutants and the role of aerosols. Several nesting schemes and sub-grid models are also being investigated.
Ozone transfer from the stratosphere
Some ozone in the troposphere (below ca 15 km) is brought down from the stratosphere during the passage of vigorous fronts and violent storms. It is necessary to include such contributions in the models, and work is being done on this in both EUMAC and GLOMAC.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
(Joint project with the EC)
The Ground-based Cloud Experiment (GCE) studies the processes involved in the formation of clouds and fogs, and their acidity.
Coordinator: Sandro Fuzzi (CNR, Bologna)
Deputy: Hans-Christen Hansson (University of Lund)
Objectives:
Highlights of GCE field campaigns
Perhaps the most challenging problem in atmospheric chemistry is presented by clouds and their role in processing aerosols and gaseous pollutants. GCE has assembled 15 research groups from 7 countries who have now conducted three intensive field campaigns at sights chosen for their particular cloud types: the Po valley (Italy) in 1989, Kleiner Feldberg (Germany) in 1990, and Great Dun Fell (UK) in 1993.
The results of the first two experiments have already been analysed and are in part published in the scientific literature. The relationship between aerosol chemical composition and hygroscopicity and cloud water chemical composition has been addressed, together with the study of gas/liquid partitioning of atmospheric trace species. When the analysis of data from Great Dun Fell is complete, detailed information on physical and chemical processes in clouds characterised by different updraught and pollution conditions will be available.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Rainer Friedrich (University of Stuttgart)
Deputy: Remy Bouscaren (CITEPA, Paris)
Scientific aims:
Estimates of pollutant emissions by the European countries
GENEMIS has taken over the estimation of emissions. Working from estimates given by governments and socio-economic data, they are preparing a data base of information which can be used in the models throughout Europe. Much of their work relies on information provided by the European Commission and the UN-ECE (EMEP).
Ozone transfer from the stratosphere
Some ozone in the troposphere (below ca 15 km) is brought down from the stratosphere during the passage of vigorous fronts and violent storms. It is necessary to include such contributions in the models, and work is being done on this in both EUMAC and GLOMAC.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Henning Rodhe (Stockholm University)
Deputy: Paul Crutzen (Max-Planck Institute, Mainz)
Scientific aims:
Changes in the global atmosphere
The global model computations in GLOMAC indicate that:
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Peter Warneck (MPI, Mainz)
Deputy: Christiaan Vinckier (University of Leuven)
Scientific aims:
Highlights of the scientific results
The reaction scheme for the oxidation of sulphur dioxide, S02, and sulphite to sulphate comprises many interlocking reactions involving transient intermediate species which are difficult to study independently. The situation is complicated further by the catalytic effect of trace amounts of transition metals present in aerosol particles. However the HALIPP investigators have added appreciably to the understanding in this field, with many studies on aspects of these reactions.
Two newly developed techniques within HALIPP have given sticking coefficients of ammonia, NH3, and nitrous acid, HONO, which are important in understanding the uptake of these gases by water droplets in cloud and fog.
!! Old EUROTRAC subproject (which finished at the end of 1995) !!
Coordinator: David Brassington (Imperial College, London)
Scientific aims:
Highlights of JETDLAG current scientific results
The technique used in JETDLAG is an infrared absorption spectroscopy with tuneable diode laser light sources whose narrow line widths offer the possibility of high selectivity for a large number of interesting compounds in the atmosphere. Much effort has been devoted to improving the sensitivity (a novel frequency modulated technique has been developed) and to multiplexing the instruments so that they can make simultaneous measurements of several pollutant concentrations. Instruments have been developed for use on aircraft and for laboratory and field measurements.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Georges Le Bras (CNRS, Orléans)
Deputy: Karl-Heinz Becker (University of Wuppertal)
Scientific aims:
Highlights of LACTOZ scientific results
The research undertaken by the 25 LACTOZ groups concerns reactive radicals in the atmosphere. For example, progress has been made in the knowledge of the oxidation of volatile organic compounds (VOCs), more specifically on the fate of peroxy radicals formed after the primary reaction of VOCs with OH radicals whose rates change markedly with the type of VOC. New data have also been produced on the first steps of the mechanism of the night-time NO3 initiated oxidation of VOC which is particularly efficient for alkenes.
LACTOZ groups have produced definitive publications on the chemistry of the nitrate radical (N03) and organic peroxy radicals, as well as detailed reaction schemes for day and night-time oxidation of VOCs together with nitrogen chemistry.
!! The AP finished at the end of 1995 !!
An "Application Project" has recently been formed to ensure that the scientific results obtained by the EUROTRAC research groups are properly assimilated. The results will be provided to policy makers in the various governments and agencies responsible for environmental management within Europe.
Themes studied in the Application Project:
The following points will be considered within both themes 1 & 2
Executive Summary of the Application Project Report
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Jens Boesenberg (MPI, Hamburg)
Deputy: Gerard Ancellet (CNRS, Paris)
Scientific aims:
Highlights of TESLAS current scientific results
Vertical Ozone profiles from lidar measurements
TESLAS is developing lidar instruments with which vertical profiles of the ozone and aerosol concentrations in the atmosphere can be determined from ground level up to the top of the troposphere (ca. 12 km). An intercomparison experiment in 1991, TROLIX, measured ozone profiles at a site in Holland and compared the results from several instruments with those from more conventional instruments borne aloft in a helicopter. Ground-based lidars are now operating at four TOR stations to obtain vertical profiles of ozone concentrations on a regular basis for process studies and to establish a tropospheric ozone climatology.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Coordinator: Paul Simon (University Libre, Brussels)
Deputy: Reginald Colin (University Libre, Brussels)
Scientific aims:
Highlights of TESLAS current scientific results
Urban pollution measurements
TOPAS is developing long-path-length visible and ultraviolet spectrometers which measure the tiny concentrations of pollutants in the atmosphere from their absorption of light over path lengths ranging from a few hundred meters to several kilometres. An intercomparison campaign demonstrated the effectiveness of the technique in monitoring several pollutants in the air within the city of Brussels. Commercial instruments have also been developed.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
Tropospheric Ozone Research (TOR): European network of field stations used to study the behaviour of ozone on a regional scale and to measure the concentrations of trace constituents related to photochemical pollution in the troposphere.
Coordinator: Dieter Kley (KFA, Julich)
Objectives:
Highlights of TOR current scientific results
One major contribution by the TOR project is the establishment of nearly 30 stations throughout Europe, equipped with highly sophisticated instrumentation to study the formation, transport and distribution of ozone in the troposphere.
Ozone levels in the troposphere are increasing. Measurements at Mace Head (Ireland) show an average ozone increase of 1.4 ppb per year in the clean air on the western edge of Europe; a similar increase has been observed in the free troposphere from measurements on the Zugspitze (Germany)at 300 m.
Analysis of the historical records since the beginning of the century at Pic du Midi (France) shows that there has been roughly a three-fold increase in ozone, and the rate of increase itself is increasing markedly.
These increases can only be attributed to man's activities and ma have far-reaching effects on health and climate in the future.
!! Old EUROTRAC Subproject (finished at the end of 1995) !!
(Joint project with the EC)
TRACT has mounted a large field campaign to study the effect of complex terrain, such as hills and valleys, on the transport of pollutants.
Coordinator: Franz Fiedler (KfK, Karlsruhe)
Deputy: Niels Otto Jensen (Riso National Laboratory, Roskilde)
Scientific aims:
Highlights of TRACT scientific results
The experimental area for the TRACT campaign in September 1992 covered most of Baden Wuertemberg in Germany and parts of France and Switzerland. Five aircraft collected data over the area together with several motor gliders and balloons.
On the ground a number of special measuring sites were set up, and national monitoring networks in France, Switzerland and Germany were also involved.
The ground level equipment ran continuously throughout the experimental period, and three special intensive observational phases of 24 or 36 hours were completed. A field phase report has been recently published.
Ten separate databases have been established for aerological data, synoptic data, aircraft measurements, surface measurements, tracer measurements, background data, land-use data and topography, the emission inventory, aircraft measurements in the nested area and for deposition data. When the data have been submitted and checked for consistency the ten will be combined in the TRACT database. Great efforts were made to ensure that data of good quality and comparability were collected so that now EUROTRAC is in possession of perhaps the best data set ever obtained from this sort of study.
The fully interpreted the data should provide a better understanding of the way pollutants are transported through and over complex terrain and how and in what quantity pollutants are handed over from the boundary layer close to the ground into the free troposphere above.
Peter Borrell, EUROTRAC ISS
GSF-Forschungszentrum für Umwelt und Gesundheit
Kühbachstraße 11 D-81543 München, Germany.
fax: +49-89-651 088 19; e-mail: eurotrac.gsf.de