Objetivo To study the exchange processes of NOx and O3 between the atmosphere and forest and reduce the uncertainty in estimates of the exchange rates. Ozone (O3) and nitrogen oxides (NOx) are key elements in tropospheric chemistry and are associated with many environmental issues. Terrestrial ecosystems, represent a major sink by dry deposition for tropospheric O3. Other processes are more important for NOx (NO + NO2) but its atmospheric deposition contributes to acidification and eutrophication. Knowledge on exchange processes of these gases is very limited. Measurements carried out recently have shown that current estimates of dry deposition fluxes of NOx may differ significantly from the true fluxes. To define optimal emission reduction strategies to limit environmental effects a better knowledge of these processes is required. The impact of the NOX emissions on regional oxidant production will be assessed. Specific objectives are to: 1) Measure fluxes of O3 and NOx above and below the forest crown and establish the relation between these fluxes and emissions of NO from the forest floor. 2) Assess the influence of biogenic emissions of NO and hydrocarbons on the deposition of O3 and improve estimates of the dry deposition velocity of O3. 3) Study the climatology of NOx exchange to coniferous forest from long-time observations. 4) Study the relation between forest floor emissions and the input of nitrogen from the atmosphere. 5) Estimate the emission of NOx oxides from forests in Europe and assess the effect of these emissions on regional O3 production by model calculations. In order to meet these objectives measurements of fluxes of NOx and O3 will be made at different forest sites in the Netherlands, Denmark and Great Britain. The sites will differ in forest type, nitrogen load, soil nutrient status and stand architecture. Micro meteorological methods will be used to measure the flux whereas enclosures will be used to measure exchange between the soil and air. The results of a, necessarily, limited number of measurements will be interpreted using a comprehensive canopy exchange model. This model includes detailed descriptions of canopy exchange processes, chemical reactions, soil exchange and turbulence above and below the canopy. Using parameterized results of the experimental work the impact of NOx emissions by biogenic sources on regional O3 formation (especially in rural areas) will be investigated using an existing regional transport model. A large scale model will be used to the assess influence of biogenic NOx emissions across Europe. Ámbito científico natural scienceschemical sciencesorganic chemistryhydrocarbonsnatural sciencesbiological sciencesecologyecosystemsnatural sciencesearth and related environmental sciencesatmospheric sciencesclimatology Programa(s) FP4-ENV 2C - Specific programme of research and technological development in the field of environment and climate, 1994-1998 Tema(s) 01020102 - Tropospheric physics and chemistry Convocatoria de propuestas Data not available Régimen de financiación CSC - Cost-sharing contracts Coordinador NETHERLANDS ORGANISATION FOR APPLIED SCIENTIFIC RESEARCH - TNO Aportación de la UE Sin datos Dirección Laan van Westenenk 501 7300AH APELDOORN Países Bajos Ver en el mapa Coste total Sin datos Participantes (3) Ordenar alfabéticamente Ordenar por aportación de la UE Ampliar todo Contraer todo FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V. Alemania Aportación de la UE Sin datos Dirección Kreuzeckbahnstrasse 19 82467 GARMISCH-PARTENKIRCHEN Ver en el mapa Coste total Sin datos RISOE NATIONAL LABORATORY Dinamarca Aportación de la UE Sin datos Dirección Frederiksborgvej 399 4000 ROSKILDE Ver en el mapa Coste total Sin datos University of Manchester Institute of Science and Technology Reino Unido Aportación de la UE Sin datos Dirección Sackville Street M60 1QD Manchester Ver en el mapa Coste total Sin datos
