THE PROPOSAL WILL SEEK TO UNDERSTAND AND QUANTIFY THE SOLAR WIND-MAGNETOSPHERE-IONOSPHERE RESPONSE FOR EXTREME DRIVING CONDITIONS USING THE 3D MULTIFLUID MHD CODE (BATS-R-US) COUPLED TO THE INNER MAGNETOSPHERE MODULE (CIMI) THE MODULE OF IONOSPHERIC ELECTRODYNAMICS AND THE OUTFLOW MODULE. HISTORICAL DATA AVAILABLE FOR EXTREME GEOMAGNETIC STORMS WILL BE COMPARED WITH THE SIMULATIONS WHEN AVAILABLE. SCIENTIFIC OBJECTIVES: A FEW SCIENTIFIC TOPICS ARE SELECTED FOR DETAILED ANALYSIS INCLUDING THE RESPONSE OF THE COUPLED MAGNETOSPHERE-IONOSPHERE SYSTEM TO CARRINGTON-TYPE EVENTS PAYING ATTENTION TO THE ROLE OF RING CURRENT POPULATION AND THE ROLE OF IONOSPHERIC EFFECTS AND THE ROLE OF SOLAR WIND DRIVERS. THE PROPOSAL WILL STUDY PHYSICAL MECHANISMS THAT COULD EXPLAIN UNUSUALLY FAST RECOVERY RATE FOR THE CARRINGTON EVENT. THESE PROCESSES INCLUDE ELEVATED O+ OUTFLOW AND FASTER RATE OF CHARGE-EXCHANGE LOSSES IONOSPHERIC EFFECTS MAGNETOPAUSE LOSSES WAVEPARTICLE INTERACTIONS. IN RELATION TO THE APPLICATIONS OF SPACE WEATHER WE WILL ALSO EXAMINE THE RESPONSE OF ELECTRONS IN THE ENERGY RANGE 5-50 KEV IN THE INNER MAGNETOSPHERE AND ALONG GEO ORBIT. THE RESPONSE OF THE ELECTRON FLUXES WILL BE STUDIED AS A FUNCTION OF THE STRENGTH OF THE STORMS IN ORDER TO FIND OPTIMAL CONDITIONS FOR FORMATION OF INTENSE ELECTRON FLUXES.