Group IV Impact of SST in the REGCM on the Spring Rainfall Over Middle East Asia Azadi M. Islamic Republic of Iran Meteorological Organization Singh G. P. Indian Institute of Technology Delhi, India Mohandas S. National Center for Medium Range Weather Forecasting, India ICTP Workshop on the theory and use of regional climate models 26 May June 2003 Trieste Italy

Model Configuration Centarl Lon/Lat: 60 E, 28 N Grid distance: 45 Km Time step:150 s Map Projection:Lambert Convection: Grell with AS and FC closures Number of Grid points:100 (EW) ; 80 (SN) Simulation period:April and May ‘97

Conclusions  Model in general over-estimated the rainfall.  Grell convection scheme with AS closure seems to produce rainfall closer to CRU observations compared to FC closure.  Model showed remarkable ability to positively simulate the effect of SST on land- sea contrast.

Future Plans  Test the performance of REGCM in the simulation of mean precipitation during monsoon season and test the model resolution on the simulation results through various sensitivity experiments.  Study on regional features within troposphere during selected contrasting years (wet and dry) of important meteorological parameters at various atmospheric levels to see the anomalous climatic patterns.  Detail study on the evolution of seasonal mean monsoon circulation features from mid-latitude circulation in response to the Eurasian snow depth in winter/spring. In order to separate the influence of Eurasian snow from the Pacific SST, care will be taken so that the selected cases of high (low) snow years followed by deficient (excess) ISMR will not influenced by ENSO.