OCEAN-ATMOSPHERE INTERACTION IS CENTRAL TO THE CLIMATE SYSTEM WITH EXCHANGES OF HEAT AND MOMENTUM DRIVING BOTH ATMOSPHERIC AND OCEANIC VARIABILITY AND CIRCULATION ACROSS A WIDE-RANGE OF TIME AND SPATIAL SCALES. THESE INTERACTIONS ARE OFTEN CHARACTERIZED BY COUPLING BETWEEN THE ATMOSPHERE AND OCEAN WHERE SURFACE FLUXES INDUCE VARIABILITY ON ONE-SIDE OF THE AIR-SEA INTERFACE THAT THEN FEEDS BACK TO MODIFY THE EVOLUTION OF THE OTHER FLUID. HOWEVER DESPITE A GROWING RECOGNITION THAT SURFACE OCEAN VARIABILITY IS RICH WITH PROCESSES AT THE SUBMESOSCALE (HORIZONTAL SCALES OF 0.1-10 KM) THE ROLE OF THIS VARIABILITY IN AIR-SEA INTERACTION AND WHETHER THERE ARE SIGNIFICANT COUPLED INTERACTIONS AT THIS SCALE REMAINS LARGELY UNKNOWN. THE WORK PROPOSED HERE WILL THEREFORE EXTEND THE FRONTIER OF AIR-SEA COUPLING DOWN TO FINER SCALES THAN HAVE PREVIOUSLY BEEN ACCESSIBLE DEVELOPING A MORE COMPLETE UNDERSTANDING OF THE MECHANISMS AND IMPACT OF AIR-SEA COUPLING AT THE SUBMESOSCALE AND THE CONSEQUENCES FOR OCEAN CIRCULATION. THESE ADVANCES WILL BE ENABLED THROUGH LEVERAGING UNIQUE AND TIMELY HIGH-RESOLUTION OBSERVATIONS OF THE AIR-SEA INTERFACE PLANNED TO BE COLLECTED AS PART OF THE NASA EARTH VENTURE SUBORBITAL-3 SUB-MESOSCALE OCEAN DYNAMICS EXPERIMENT (EVS-3 S-MODE) HIGH-RESOLUTION COUPLED GLOBAL SIMULATIONS (GEOS/ECCO) AND SATELLITE DATA. THE PROPOSED WORK HAS THREE PRIMARY OBJECTIVES: OBJECTIVE 1: IMPROVE OUR UNDERSTANDING OF THE BASIC PHYSICAL MECHANISMS OF AIR-SEA INTERACTION AND COUPLING AT THE OCEAN SUBMESOSCALE. UNIQUE NEW OBSERVATIONS PLANNED AS PART OF THE NASA EVS-3 S-MODE PROJECT WILL BE ANALYZED IN CONCERT WITH HIGH RESOLUTION PROCESS STUDY MODELING TO CLARIFY THE BASIC PHYSICAL MECHANISMS THROUGH WHICH THE OCEAN AND ATMOSPHERE INTERACT AT SMALL SCALES. OBJECTIVE 2: QUANTIFY THE REGIONAL AND GLOBAL IMPORTANCE OF FINE-SCALE AIR-SEA INTERACTION. A NEW HIGH-RESOLUTION GLOBAL 1/48 COUPLED GEOS/ECCO SOLUTION PROVIDES A TEST BED FOR EVALUATING EXISTING AND NEW THEORIES OF AIR-SEA INTERACTION. THE FOCUS OF THIS ACTIVITY WILL BE ON HOW AIR-SEA INTERACTION PROCESSES AFFECT THE LARGE-SCALE PROPERTIES OF THE OCEAN MIXED-LAYER AND CIRCULATION. OBJECTIVE 3: ASSESS THE CAPABILITIES OF CURRENT AND FUTURE REMOTE SENSING FOR OBSERVING SUBMESOSCALE AIR-SEA INTERACTION. HIGH RESOLUTION SATELLITE DATA WILL BE USED FOR OBSERVATIONAL CASE STUDIES OF AIR-SEA INTERACTION AT THE SUBMESOSCALE PROVIDING BOTH A MORE COMPLETE DESCRIPTION OF THE RELEVANT PHYSICAL PROCESSES AND GUIDANCE ON THE OBSERVATIONAL REQUIREMENTS FOR REMOTE SENSING. IMPACT AND RELEVANCE: THE PROPOSED WORK WILL THEREFORE IMPROVE OUR UNDERSTANDING OF COUPLED AIR-SEA INTERACTION AT THE OCEAN SUBMESOSCALE A KEY SOURCE OF UNCERTAINTY IN OUR ABILITY TO UNDERSTAND AND PREDICT OCEAN CIRCULATION AND VARIABILITY. THIS RESPONDS DIRECTLY TO THE NASA PHYSICAL OCEANOGRAPHY PROGRAM S GOAL OF UNDERSTANDING THE OCEAN S ROLE IN CLIMATE VARIABILITY AND PREDICTION AND THE PRIORITY RESEARCH THEME OF ANALYSIS AND INTERPRETATION OF OCEAN CIRCULATION USING SATELLITE AND IN SITU DATA DATA-DERIVED PRODUCTS AND NASA OCEAN STATE ESTIMATES AND IS A PRIORITY OF THE U.S. CLIVAR PROGRAM. ANALYSIS OF THE NASA EVS-3 S-MODE DATA IN CONJUNCTION WITH NEW PROCESS-STUDY MODELS WILL ADD SIGNIFICANT VALUE TO THAT PROJECT. LIKEWISE WE WILL PROVIDE GROUND-TRUTH VALIDATION OF THE NEW GEOS/ECCO SIMULATION WHICH WILL BE USED WIDELY IN THE OCEANOGRAPHIC COMMUNITY INCLUDING TO SUPPORT THE SCIENCE OBJECTIVES OF THE UPCOMING NASA SWOT MISSION. ANALYSIS OF SATELLITE DATA ALONG WITH GEOS/ECCO WILL HELP GUIDE THE INTERPRETATION OF CURRENT AND FUTURE SCATTEROMETER WIND DATA AND HELP SHAPE THE SCIENCE REQUIREMENTS OF FUTURE MISSIONS. FINALLY AS PART OF THIS PROJECT A PHD STUDENT AND UNDERGRADUATE SUMMER RESEARCHER WILL BOTH BE TRAINED IN PHYSICAL OCEANOGRAPHY AND SATELLITE DATA ANALYSIS.