THE OBJECTIVE OF THE PROPOSED RESEARCH IS TO SYSTEMATICALLY CHARACTERIZE THE MICROPHYSICS AND VERTICAL STRUCTURE OF OROGRAPHIC PRECIPITATION ON THE TOPOGRAPHIC ENVELOPE OF MAJOR MOUNTAIN RANGES IN THE TROPICS AND SUBTROPICS (TRMM LATITUDE BELT) LEADING TO IMPROVED REPRESENTATION OF GOVERNING PROCESSES IN MICROPHYSICAL MODELS AND PHYSICAL PARAMETERIZATIONS AND TO SUPPORT GPM GROUND-VALIDATION ACTIVITIES. THE RESEARCH CONSISTS OF FOUR PRINCIPAL ELEMENTS:I)INTEGRATION AND ANALYSIS OF FIELD MEASUREMENTS FROM MOUNTAIN TRANSECTS INCLUDING THE SOUTHERN APPALACHIAN MOUNTAINS (3-5) AMERICAN CORDILLERA (2-5) WESTERN GHATS (1) CENTRAL AND WESTERN HIMALAYAS (2) AND CENTRAL AFRICA (2) AND GROUND-VALIDATION OF GPM PRECIPITATION PRODUCTS; II) MICROPHYSICAL MODELING INTEGRATING GPM DPR REFLECTIVITY PROFILES CO-LOCATED VERTICAL REFLECTIVITY PROFILES AND DISDROMETER MEASUREMENTS TO ELUCIDATE THE PROCESSES GOVERNING THE VERTICAL DISTRIBUTIONS OF RAINDROP SIZE DISTRIBUTION (DSDS) IN THE LOWER TROPOSPHERE ABOVE REGIONAL OROGRAPHY; III) DATA INTEGRATION ANALYSIS AND SYNTHESIS INCLUDING THE USE OF DEEP LEARNING TOOLS TOWARD IDENTIFYING EMERGENT REGIMES (ENGINEERING MULTIDIMENSIONAL FEATURES IN DATA ANALYTICS PARLANCE) THAT CAPTURE THE PRINCIPAL MODES OF PRECIPITATION MICROPHYSICS CONDITIONAL ON PRESENT (NEAR REAL-TIME) ENVIRONMENTAL CONDITIONS INCLUDING THE SPACE-TIME CO-ORGANIZATION OF MESOSCALE WEATHER REGIONAL AND LOCAL HYDROMETEOROLOGY AEROSOL LOADS LANDFORM AND LAND-COVER THAT IS ENVIRONMENT-AWARE OROGRAPHIC MICROPHYSICS; AND IV) DEVELOPMENT OF A HYBRID INFERENCE AND PROCESS-DRIVEN MODELING FRAMEWORK TO COMBINE (II) AND (III) FOR QUANTITATIVE PREDICTION (DOWNSCALING) OF PRECIPITATION IN MOUNTAINOUS REGIONS AT HIGH SPATIAL RESOLUTION. WE ALSO ENVISION THE DEVELOPMENT OF A DIAGNOSTIC ON-DEMAND-TOOL FOR IMAGING THE VERTICAL STRUCTURE OF PRECIPITATION DSDS IN REGIONS OF COMPLEX TERRAIN AS A KEY OUTCOME OF THIS PROJECT. THE PROPOSAL FITS THE RESEARCH CATEGORY REGARDING THE USE OF SATELLITE AND GROUND MEASUREMENTS FOR PHYSICAL PROCESS STUDIES TO GAIN A BETTER UNDERSTANDING OF PRECIPITATION THE GLOBAL WATER CYCLE CLIMATE WEATHER AND CONCOMITANT IMPROVEMENTS IN NUMERICAL MODELS WITH A FOCUS ON OROGRAPHIC PRECIPITATION IN THE GLOBAL TROPICS AND SUBTROPICS. THE RESEARCH OUTCOMES INCLUDING COMPREHENSIVE MICROPHYSICAL DATA SETS ARE EXPECTED TO BE USEFUL TO ALGORITHM DEVELOPERS AND TO SUPPORT BROADER PRECIPITATION SCIENCE AND HYDROLOGIC APPLICATIONS THAT REQUIRE QUANTITATIVE PRECIPITATION ESTIMATION AT HIGH SPATIAL RESOLUTION IN COMPLEX TERRAIN.