Obiettivo To improve the understanding and the representation in models ofthe small scale physical processes playing a role in the surfaceenergy fluxes and mass balance over the polar ice caps (Greenlandand Antarctica).The mass balance of the polar ice caps depends strongly on theinteraction with the atmopshere. Due to the large extent of theice-sheets sloped surface, katabatic winds develop and influencestrongly the snow and ice energy balance. The role of thesewinds is very important for the ice- sheets mass balance, mainlyalong the ice margin and over the ablation zone, where thetemperature may increase above 0º C in summer. Thesephenomena are of typical mesoscale size and are badly treated in thecurrent General Circulation Models (GCM's).In the past, this fact has been taken into account in a rathersimple way mainly because of a lack of experimental data from thepolar regions. But recently, several experiments have beenconducted in the polar regions and measurements of atmosphericsurface fluxes are available. It is now possible to test andvalidate mesoscale meteorological models on these data, and thenuse the model results to infer the behaviour of theice-atmosphere interaction in various conditions.The project will use the data sets obtained from the GreenlandIce Margin Experiments (GIMEX-90 and 91) for the Artic zone, andthose from Terra Nova Bay and IAGO for the Antarctic. Thesensible and latent fluxes are extracted from the observationsusing adequate profile methods and the data are carefullyexamined to study the albedo behaviour of the ice sheet, thisbeing an important factor of the surface energy balanceTwo meteorological mesoscale models are used to perform thesimulations. The model physics is improved to come reasonnablyclose to the observations. The physics taken into account in themodels must include such processes as: temperature stratificationin the katabatic flow, transport of snow, radiative cooling overthe icesheet and iceshelf, effect of the snow-free tundra, albedovariation in function of height and summer melting in theablation region. The simulations schedule include also asensitivity study to these effects, and particularly the effectof typical high latitude clouds on the surface fluxes and thus onthe melting rates.Finally, a modelling experiment will be conducted to infer themodification to the current fluxes and ablation rates expectedwhile forcing the models with external conditions foreseen forthe mid next century, due to enhanced greenhouse effect aspredicted by the current GCM's. Programma(i) FP3-ENV 1C - Specific research and technological development programme (EEC) in the field of the environment, 1990-1994 Argomento(i) 0102 - Anthropogenic climate change Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore UNIVERSITE CATHOLIQUE DE LOUVAIN Contributo UE Nessun dato Indirizzo 2,Chemin du Cyclotron 2 1348 LOUVAIN-LA-NEUVE Belgio Mostra sulla mappa Costo totale Nessun dato Partecipanti (2) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto UNIVERSITE PAUL SABATIER DE TOULOUSE III Francia Contributo UE Nessun dato Indirizzo Avenue Edouard Belin 14 31400 TOULOUSE Mostra sulla mappa Costo totale Nessun dato UTRECHT UNIVERSITY Paesi Bassi Contributo UE Nessun dato Indirizzo 5,Princetonplein 5 3584 CC UTRECHT Mostra sulla mappa Costo totale Nessun dato