OBSERVATIONS INDICATE THAT FAST INTERMITTENT FLOWS ARE A PRIMARY MODE OF TRANSPORT IN THE PLASMA SHEET WHICH SERVES AS A RESERVOIR OF PLASMA POPULATIONS THAT ARE THE SOURCE OF THE INNER MAGNETOSPHERIC ENVIRONMENT. THE FLOW PERTURBATIONS ARE ASSOCIATED WITH STRONG FIELD-ALIGNED CURRENTS THAT COMMUNICATE THE MAGNETIC STRESSES TO THE IONOSPHERE AS ALFVEN WAVES WHICH CAN COUPLE TO KINETIC SCALES LEADING TO FLOW BRAKING AND PARTICLE HEATING. A GROWING NUMBER OF OBSERVATIONAL STUDIES HAVE HIGHLIGHTED THE IMPORTANCE OF KINETIC SCALE ALFVEN WAVES ON THE PLASMA SHEET-IONOSPHERE COUPLING. ALTHOUGH FUNDAMENTALLY IMPORTANT THE GENERATION STRUCTURE AND ROLE OF ALFVEN MODE WAVES IN THE TAIL ARE POORLY UNDERSTOOD. THE WAVE PROCESSES MAY TAKE PLACE IN REGIONS OF FAST FLOWS FLOW BRAKING AND THE DIPOLE-LIKE FIELD. GIVEN THE MULTI-SCALE AND NONLINEAR NATURE OF THE PROBLEM COMPUTER SIMULATIONS THAT CAN DESCRIBE SCALES RANGING FROM GLOBAL DRIVERS TO THE ION GYRORADIUS GUIDED BY MULTIPOINT OBSERVATIONS THAT ARE NECESSARY TO REACH A COMPLETE UNDERSTANDING OF THE COUPLING PROCESSES. THE GOAL OF THE PROPOSED STUDY IS TO UNDERSTAND THE GENERATION AND DYNAMICS OF ALFVEN WAVES/KINETIC ALFVEN WAVES (KAWS) ASSOCIATED WITH THE TAIL FAST FLOWS IN THE SELF-CONSISTENT SOLAR WIND-MAGNETOSPHERE-IONOSPHERE COUPLING BY COMPARING OBSERVATIONS WITH GLOBAL HYBRID SIMULATIONS.THE OBJECTIVES OF THIS PROJECT ARE TO ADDRESS THE FOLLOWING SPECIFIC SCIENCE QUESTIONS: (1) WHAT ARE THE ROLES OF MAGNETIC RECONNECTION COMPRESSIONAL WAVES AND THE DIPOLE-LIKE FIELD IN THE GENERATION OF ALFVEN WAVES AND KAWS AND ARE THEY TYPICALLY OBSERVED AND GENERATED IN ASSOCIATION WITH MAGNETOTAIL FAST FLOWS? (2) HOW DO ALFVEN WAVE GENERATION EVOLUTION AND GLOBAL STRUCTURE DEPEND ON IMF CONDITIONS AND SOLAR WIND MACH NUMBERS? (3) WHAT ARE THE CHARACTERISTIC SPECTRA GLOBAL DISTRIBUTIONS POYNTING FLUX AND FIELD ALIGNED CURRENTS ASSOCIATED WITH ALFVEN MODE WAVES IN THE NEAR-TAIL AND WHAT DO THESE PROPERTIES IMPLY FOR ION HEATING AND ACCELERATION?METHODOLOGY: THE ABOVE SCIENCE QUESTIONS WILL BE ANSWERED USING DATA FROM THE THEMIS SPACECRAFT AND OMNI DATA SETS TOGETHER WITH NUMERICAL SIMULATIONS BASED ON A THREE-DIMENSIONAL (3-D) GLOBAL HYBRID MODEL. THE PRIMARY NUMERICAL METHODOLOGY IS THROUGH SIMULATIONS USING THE AUBURN 3-D GLOBAL HYBRID CODE THAT INCLUDES BOTH THE DAYSIDE AND NIGHT SIDE MAGNETOSPHERE UNDER VARIOUS SOLAR WIND CONDITIONS ASSOCIATED WITH STORM/SUBSTORM. THE SIMULATION DOMAIN EXTENDS FROM THE SOLAR WIND AT GSM X=+20RE TO X=-60RE IN THE TAIL WHICH ALLOWS US TO CONSIDER THE SOLAR WIND CONTROL OF TAIL DYNAMICS. THIS MODEL IS APPROPRIATE FOR THE PROPOSED SIMULATIONS AND CAN DESCRIBE PHYSICAL PROCESSES THAT COUPLE ENERGY FROM GLOBAL SCALE DRIVERS OF ALFVEN WAVES TO ION KINETIC SCALES. THE SIMULATION STUDY WILL BE COORDINATED WITH SATELLITE DATA ANALYSIS OF THE THEMIS MISSION AND OMNI DATA SETS. DATA FROM THE THEMIS MISSION IS AVAILABLE THROUGH A WEB INTERFACE AND COLLABORATION WITH MEMBERS OF THE THEMIS SCIENCE TEAM. OMNI IS AN OPEN DATA SET PROVIDED AT HTTP:// OMNIWEB.GSFC.NASA.GOV/FORM/OMNI_MIN.HTML. DATA AND RESULTS OF THE INVESTIGATIONS WILL BE PUBLISHED IN REFEREED JOURNALS.RELEVANCE TO NASA: THE PROPOSED TOPICS FIT IN THE BROAD CATEGORIES OF MAGNETOSPHERE UNDER THE NASA HELIOPHYSICS SUPPORTING RESEARCH PROGRAM (SOLICITATION NNH16ZDA001N-HSR) MOST RELEVANT TO THE SCIENCE AREA NO. 10 MAGNETOSPHERE-IONOSPHERE COUPLING/MAGNETOTAIL BUT ALSO TOUCH NO. 8 SOLAR WIND-MAGNETOSPHERE COUPLING. THE PROPOSED INVESTIGATIONS ARE OF HIGH PRIORITY BECAUSE THEY COMBINE USE OF DATA FROM CURRENT NASA SPACECRAFT (THEMIS SPACECRAFT AND OMNI DATA SETS) TOGETHER WITH THEORY AND NUMERICAL SIMULATION (3-D GLOBAL HYBRID MODEL) TO ADDRESS THE SPECIFIC HELIOPHYSICS DECADAL SURVEY GOAL NO. 2. DETERMINE THE DYNAMICS AND COUPLING OF EARTH'S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS.