Objetivo The first objective is to evaluate the effects of heterogeneous chemistry on the ozone level and to calculate the effects of large scale transport on the global ozone budget.The second objective is a critical comparison between model results and the measurements about the effect on the stratospheric chemistry of the Pinatubo eruption.The third objective of this project is to calculate the effect of substitution policies of CFC with HCFC.The goals described above will be achieved by using numerical modelling techniques based on two and three dimensional models of the atmosphere. All groups participating to this project have a two dimensional model including heterogeneous chemistry with the aerosol surface density affecting the reaction rates parameterized in terms of seasonal temperature changes. Within the same groups two microphysics codes (DMI and UNIVAQ) have been tested and will be merged with existing two dimensional models. These codes divide the size distribution range of radii (from 10-3 to 102 m) in several bins (from 40 to 200) and a numerical computation is carried out to build a size distribution that may be a function of environmental variables like cooling rates, water vapor and nitric acid content.One group is running a general circulation model of the stratosphere including chemistry. This spectral model covers the altitude range from the surface to about 70 km and uses a rhomboidal truncation with six waves. The model also includes a radiative code which calculated explicitly the contribution from carbon dioxide, water vapor and ozone. Ámbito científico natural sciencesearth and related environmental sciencesatmospheric sciences Programa(s) FP3-ENV 1C - Specific research and technological development programme (EEC) in the field of the environment, 1990-1994 Tema(s) Data not available Convocatoria de propuestas Data not available Régimen de financiación CSC - Cost-sharing contracts Coordinador Università degli Studi dell'Aquila Aportación de la UE Sin datos Dirección Via Vetoio 10 67010 Coppito l'Aquila Italia Ver en el mapa Coste total Sin datos Participantes (5) Ordenar alfabéticamente Ordenar por aportación de la UE Ampliar todo Contraer todo BELGIAN INSTITUTE FOR SPACE AERONOMY Bélgica Aportación de la UE Sin datos Dirección 3,Ringlaan 3 1180 BRUXELLES Ver en el mapa Coste total Sin datos DANISH METEOROLOGICAL INSTITUTE Dinamarca Aportación de la UE Sin datos Dirección 100,Lyngbyvej 100 2100 KOEPENHAGEN Ver en el mapa Coste total Sin datos NORWEGIAN INSTITUTE FOR AIR RESEARCH Noruega Aportación de la UE Sin datos Dirección Instituttveien 18 2027 KJELLER Ver en el mapa Coste total Sin datos UNIVERSITE PIERRE ET MARIE CURIE - PARIS VI Francia Aportación de la UE Sin datos Dirección Place Jussieu 4 Tour 15 75230 PARIS Ver en el mapa Coste total Sin datos University of Oslo Noruega Aportación de la UE Sin datos Dirección 0315 Oslo-Blindern Ver en el mapa Coste total Sin datos