IN THIS PROJECT WE WILL USE STATE-OF-THE-ART COASTAL ALTIMETRY DATA TOGETHER WITH IN SITU DATA TO IMPROVE ESTIMATES OF THE SOUTH ATLANTIC MERIDIONAL OVERTURNING CIRCULATION (SAMOC) VOLUME TRANSPORT AT 34.5 S. WE WILL COMPARE THIS IMPROVED TRANSPORT TO INDEPENDENT ESTIMATES FROM THE NASA SUPPORTED GRACE MISSION. THE SAMOC IS A MAJOR COMPONENT OF THE EARTH CLIMATE SYSTEM AND AS SUCH IT IS A KEY RESEARCH TOPIC FOR CLIVAR. OUR PROJECT IS THUS VERY RELEVANT TO THE FIRST OF THE THREE RESEARCH THEMES IDENTIFIED IN THE PHYSICAL OCEANOGRAPHY PROGRAM. TO ESTIMATE THE TRANSPORT INSHORE OF THE 34.5 S MOORING ARRAY ON EACH SIDE OF THE BASIN WHICH IS CURRENTLY INFERRED FROM INFREQUENT OBSERVATIONS OR FROM MODELS WE WILL MERGE DATA FROM VARIOUS SOURCES TO OBTAIN THE BEST POSSIBLE ALONG-TRACK ALTIMETRY ESTIMATES UTILIZING FIRST DATA FROM JASON-2 THEN FROM THE REST OF THE JASON SERIES. MORE SPECIFICALLY WE WILL GATHER THE DATA COMPOSING THE SEA LEVEL ANOMALY (SLA) BUDGET FROM VARIOUS SOURCES. FIRST WE WILL HAVE ACCESS TO SATELLITE RANGE ESTIMATES THAT BENEFIT FROM A TREATMENT OF THE ON-BOARD RADAR MEASUREMENTS THAT IS ADAPTED TO THE PRESENCE OF LAND IN THE FOOTPRINT OF THE ALTIMETER. SECOND WE WILL HAVE ACCESS TO WET TROPOSPHERIC CORRECTION ESTIMATES THAT ARE ADAPTED TO THE COASTAL ZONE WHERE ASSOCIATED ERRORS ARE OTHERWISE LARGE. THIRD WE WILL HAVE ACCESS TO TIDAL CORRECTIONS ESTIMATED BY HARMONIC ANALYSIS OF LONG TIME SERIES OF ALTIMETRY OBSERVATIONS WHICH OVERCOMES ISSUES OF TIDAL MODELS USED IN STANDARD ALTIMETRY. FINALLY WE WILL HAVE ACCESS TO PRODUCTS DELIVERED AT HIGHER FREQUENCY THAN STANDARD ONES ALLOWING FOR IMPROVED SPATIAL RESOLUTION. WE WILL USE OUR HIGH-QUALITY SLA TO DERIVE GEOSTROPHIC CURRENT ANOMALIES (GCA) WHICH ARE PERPENDICULAR TO THE SATELLITE TRACKS AND WELL ALIGNED WITH DOMINANT CURRENTS ON EACH SIDE OF THE BASIN. THE SLA AND ASSOCIATED GCA WILL BE EVALUATED USING IN-SITU DATA FROM THE 34.5 S MOORING ARRAY FROM TIDE GAUGES IN THE REGION AND FROM CRUISES. THE GCA WILL THEN BE USED IN COMBINATION WITH IN SITU DATA TO ESTIMATE ANOMALIES IN GEOSTROPHIC TRANSPORT ACROSS THE SATELLITE TRACKS BETWEEN THE EDGES OF THE MOORING ARRAY AND THE ADJACENT COAST ON EACH SIDE OF THE BASIN. USING DATA FROM VARIOUS SOURCES WILL ALSO ALLOW US TO QUANTIFY THE UNCERTAINTIES ASSOCIATED WITH THE SLA GCA AND TRANSPORT CALCULATIONS. THE USE OF WIND DATA BASED ON SATELLITE OBSERVATIONS WILL BE USED TO ESTIMATE THE EKMAN CONTRIBUTION TO THE TRANSPORT. THE IMPROVED TOTAL TRANSPORT AT 34.5 S COMBINING ALTIMETRY MOORINGS AND WIND DATA WILL BE COMPARED TO THE TRANSPORT ESTIMATED WITH DATA FROM THE GRACE MISSION WHICH IS CURRENTLY UNDERWAY AS PART OF A NASA PHYSICAL OCEANOGRAPHY PROJECT. THIS PROJECT WILL BENEFIT FROM INTERNATIONAL COLLABORATIONS WE HAVE ESTABLISHED WITH A LARGE NUMBER OF SCIENTISTS IN TWO GROUPS. THE FIRST INCLUDES COLLABORATORS INVOLVED IN THE DISTRIBUTION OF COASTAL ALTIMETRY DATA WHO WILL HELP US ACCESS THE MOST UP-TO-DATE PRODUCTS AND USE THEM IN THE MOST ROBUST MANNER. THE SECOND CONSISTS OF SCIENTISTS INVOLVED IN THE ANALYSIS OF THE SOUTH ATLANTIC REGION MOSTLY THROUGH THEIR PARTICIPATION IN THE 34.5 S MOORING ARRAY WHO WILL HELP US EVALUATE THE SHELF TRANSPORTS ESTIMATED DURING THE PROJECT IN THE CONTEXT OF THE REGIONAL OCEAN CIRCULATION. IN ADDITION EXPERT COLLABORATORS IN SATELLITE DATA THAT COMPLEMENT ALTIMETRY INCLUDING FROM THE GRACE MISSION ARE ALSO MEMBERS OF OUR TEAM. THIS PROJECT WILL DIRECTLY SERVE THE NASA EARTH SCIENCE RESEARCH PROGRAM GOALS AS IT ADVANCE[S] EARTH SYSTEM SCIENCE TO MEET THE CHALLENGES OF CLIMATE AND ENVIRONMENTAL CHANGE NASA S STRATEGIC GOAL 2.1 AND IMPROVE[S] THE ABILITY TO PREDICT CLIMATE CHANGES BY BETTER UNDERSTANDING THE ROLES AND INTERACTIONS OF THE OCEANS ATMOSPHERE LAND AND ICE ONE OF ITS SEVEN IDENTIFIED SCIENCE GOALS. OUR PROJECT ALSO ADDRESSES CLIMATE VARIABILITY AND CHANGE THE THIRD INTERDISCIPLINARY SCIENCE FOCUS AREA OF THIS PROGRAM.