THE SCIENCE PLAN OF THE 2ND INTERNATIONAL INDIAN OCEAN EXPEDITION (IIOE-2) HAS BEEN RECENTLY DOCUMENTED, WITH THE SIX MAJOR THEMES THAT ENCOMPASS GEOLOGIC, ATMOSPHERIC, AND OCEANOGRAPHIC RESEARCHES FROM COASTAL ENVIRONMENT TO DEEP SEA. THE PROPOSED PROJECT WILL DIRECTLY CONTRIBUTE TO TWO OF THE SPECIFIC THEMES: BOUNDARY CURRENT DYNAMICS, UPWELLING VARIABILITY, AND ECOSYSTEM IMPACTS AND CIRCULATION, CLIMATE VARIABILITY, AND CHANGE . OCEAN CIRCULATIONS IN THE SUBTROPICAL AND TROPICAL SOUTHERN INDIAN OCEAN (IO) HAVE STRONG IMPACTS ON REGIONAL AND GLOBAL CLIMATE VARIABILITY. THE PRIMARY GOAL OF THIS PROPOSED PROJECT IS TO UNDERSTAND PHYSICAL PROCESSES THAT CONTROL VARIABILITY OF SOUTHEAST AND SOUTHERN IO CIRCULATIONS ON INTRASEASONAL TO INTERANNUAL TIME SCALES. A PARTICULAR EMPHASIS IS GIVEN TO VARIABILITY OF LEEUWIN CURRENT (LC), WHICH IS ONE OF THE MAJOR BOUNDARY CURRENTS IN IO, AND ITS INFLUENCE ON THE SOUTHERN IO INTERIOR. THE PROPOSED STUDY WILL ADDRESS THE FOLLOWING ISSUES: THE IMPACT OF THE REMOTE FORCING FROM THE PACIFIC OCEAN VERSUS LOCAL FORCING OVER THE INDIAN OCEAN ON THE LEEUWIN CURRENT SYSTEM; THE INFLUENCE OF THE MADDEN-JULIAN OSCILLATION (MJO) ON THE LEEUWIN CURRENT SYSTEM AND UPPER OCEAN VARIABILITY IN THE SOUTHEAST IO VIA OCEANIC PROCESSES; THE IMPACT OF ANOMALOUS SALINITY NEAR THE SURFACE IN THE SOUTHEAST IO SUCH AS OBSERVED DURING NINGALOO NI O EVENTS ON THE UPPER OCEAN MIXING PROCESSES AND SSTS; CHARACTERISTICS OF RADIATING ROSSBY WAVES OFF THE COAST OF AUSTRALIA AND THE ASSOCIATED DOWNWELLING/UPWELLING, AND THEIR IMPACT ON INTERIOR IO VARIABILITY TO ACHIEVE THE GOAL, WE PROPOSE TO ANALYZE SATELLITE-DERIVED SEA SURFACE HEIGHT, SEA SURFACE SALINITY, SEA SURFACE TEMPERATURE, SURFACE VECTOR WIND, PRECIPITATION, AND OCEAN COLOR ALONG WITH IN-SITU DATA, OSCAR VELOCITY, AND REANALYSIS PRODUCTS. A VARIETY OF SATELLITE DATA WILL BE VALIDATED BY THE COMPARISON WITH IN-SITU OBSERVATIONS OVER THE TROPICAL AND SUBTROPICAL INDIAN OCEANS. THESE ANALYSES OF MULTIPLE SURFACE VARIABLES DERIVED FROM SATELLITE MEASUREMENTS AND SUBSURFACE VARIABLES DERIVED FROM REANALYSIS PRODUCTS WILL PROVIDE THOROUGH DESCRIPTION OF LEEUWIN CURRENT AND UPWELLING/DOWELLING VARIABILITY, AND THEIR RELATION TO ATMOSPHERIC FORCING, AND IDENTIFY KEY PHYSICAL PROCESSES THAT CONTROL THE VARIABILITY SUCH AS THE INFLUENCE FROM REMOTE OCEANS. RELEVANCE TO PHYSICAL OCEANOGRAPHY PROGRAM AND NASA'S MISSION THE PRIORITY AREAS IN THE FY17 NASA PHYSICAL OCEANOGRAPHY PROGRAM INCLUDE CONTRIBUTIONS TO SATELLITE DATA ANALYSIS EXPERTISE TO IIOE-2. ALSO, THE PROPOSED PROJECT WILL TAKE ADVANTAGES OF MULTIPLE SATELLITE OBSERVATIONS (ALTIMETRY, SURFACE WIND STRESS, SALINITY, AND OCEAN COLOR), WHICH IS AN APPROACH ENCOURAGED IN THE PROGRAM. THE PROJECT INCLUDES DIAGNOSES OF ECCO SUCH AS THE COMPARISON WITH THE IN-SITU AND SATELLITE DATA, WHICH WILL BE USEFUL FOR THE FUTURE IMPROVEMENT OF ECCO PRODUCT. FURTHERMORE, THE COMPARISON OF SATELLITE ALTIMETRY DATA WITH TIDE GAUGE DATA ALONG THE COAST AND WITHIN THE INDONESIAN SEAS WILL PROVIDE USEFUL INFORMATION FOR THE SURFACE WATER AND OCEAN TOPOGRAPHY (SWOT) SATELLITE MISSION, WHICH IS SCHEDULED TO BE LAUNCHED IN 2020, AND THUS THE GOAL OF THIS STUDY IS ALSO CONSISTENT WITH THE NASA S FUTURE MISSION.