THE SHELF AND COASTAL SEAS ALONG THE US EASTERN SEABOARD AND ALONG TO THE GRAND BANKS OF CANADA ENCOMPASS SOME OF N. AMERICA S RICHEST MARINE ECOSYSTEMS. ATTEMPTS TO DETECT MEASURE AND FORECAST SIGNIFICANT RECENT HYDROGRAPHIC CHANGES ARE TOPICS OF CONSIDERABLE IMPORTANCE TO BOTH SCIENTIFIC AND MANAGEMENT COMMUNITIES. THE NW ATLANTIC SHELF AND SLOPE SEA OCEAN CIRCULATION FEATURES EQUATORWARD SHELF AND SHELF-BREAK CURRENTS THAT CARRY COLD FRESHENED SEAWATER FROM THE LABRADOR SEA AND GULF OF ST. LAWRENCE AND INTERACT WITH THE WARMER SALTIER ATLANTIC. THIS ALONG SHORE FRESHWATER TRANSPORT HAS BEEN FOUND TO BE QUITE VARIABLE AND DIFFICULT TO ADEQUATELY MONITOR AND PREDICT IN LARGE PART BECAUSE OF LACK OF A LARGE SCALE MONITORING CAPABILITY THAT MAY NOW BE FEASIBLE USING SATELLITE SALINITY DATA. THIS COLLABORATIVE PROPOSAL BRINGS TOGETHER EXPERTS ON THE NW ATLANTIC SHELF PHYSICAL OCEANOGRAPHY (UNH) WITH EXPERTS ON UPPER OCEAN SALINITY ANALYSIS (UMD) AND SATELLITE SALINITY MEASUREMENTS (IFREMER) TO ADDRESS SEVERAL OPEN SCIENCE QUESTIONS: WHAT ARE THE SPATIAL AND TEMPORAL SIGNATURES OF SURFACE SALINITY OBTAINED FROM SPACE AND ARE THEY CONSISTENT WITH GROUND TRUTH? ARE UPPER OCEAN SALINITY AND TEMPERATURE DATA STRONGLY COVARIANT AND EQUIVALENT PROXIES FOR ADVECTIVE AND INTERANNUAL DYNAMICS? IS THERE A CLEAR TIE BETWEEN SALINITY VARIABILITY AND FRESHWATER TRANSPORT FROM THE NORTH AND LARGE SCALE ATMOSPHERIC PATTERNS SUCH AS THE NORTH ATLANTIC OSCILLATION RESPONSIBLE FOR THE CLIMATE IN THE ATLANTIC SECTOR? AN OVERALL PROJECT OBJECTIVE IS TO EVALUATE THE USEFULNESS OF OCEAN SALINITY DATA FOR EXPLORING AND MONITORING THE VARIABILITY OF THE NORTHWESTERN ATLANTIC SHELF WITH SPECIAL EMPHASIS ON REMOTE SENSING AS A TOOL TO ENHANCE SPACE/TIME SAMPLING AND TO GAIN A LARGER PERSPECTIVE OF THE CONNECTED GRAND BANKS-TO-HATTERAS SHELF/SLOPE SEA/GULF STREAM SYSTEM. THE APPROACH WILL USE A COMBINATION OF OBSERVATIONS AND NUMERICAL SIMULATIONS TO QUANTIFY THE IMPORTANCE OF HORIZONTAL ADVECTION IN REGULATING THE INTERANNUAL SALINITY ON THIS SHELF AND ASSESS HOW SATELLITE SEA SURFACE SALINITY (SSS) DATA ENHANCES UNDERSTANDING OF THE GOVERNING PHYSICS. AN EMPIRICAL USE OF SATELLITE AQUARIUS SMOS AND SMAP SSS DATA WILL BE COMBINED WITH ANALYSES USING SATELLITE ALTIMETRY SCATTEROMETRY AND SST DATA TO EVALUATE UPPER OCEAN HYDROGRAPHIC VARIABILITY ACROSS THE REGION AND AT SEASONAL AND INTERANNUAL TIME SCALES. THE DESIRE TO MAXIMIZE USE OF SATELLITE SSS DATA AS NEAR TO THE COASTLINE AND IN COLDER WATERS WILL ENTAIL CLOSE CHARACTERIZATION OF THE PRESENT AND FUTURES SCIENCE TEAM SALINITY DATA PRODUCTS USING A NEW REGION-SPECIFIC IN SITU DATA COMPILATION THAT EXPLOITS THE LARGE NUMBER OF UPPER OCEAN SALINITY MEASUREMENTS AVAILABLE IN THE NW ATLANTIC SHELF REGION THAT EXTENDS INTO THE CANADIAN MARITIMES. PERCEIVED IMPACTS STEM FROM THE STRONG INTEREST IN DETECTION OF INTERANNUAL SALINITY AND ITS CONTROLS IN ORDER TO BETTER IDENTIFY AND PREDICT BIOCHEMICAL REGIME SHIFTS (NUTRIENTS STANDING STOCKS AND CARBONATE CHEMISTRY) NOW UNDER STUDY IN THIS SYSTEM. MOREOVER THE ADDITION OF THESE NEW SHELF-WIDE SURFACE SALINITY OBSERVATIONS CAN BE USED TO ASSESS SSS AS A PROXY FOR ADVECTIVE-CONTROLLED IMPACTS IN LIEU OF OR IN ADDITION TO SEA SURFACE TEMPERATURE (SST) DATA THAT HAVE DOMINATED REGIONAL WATER MASS CHANGE INVESTIGATIONS TO DATE. THIS PROPOSAL RESPONDS TO THIS SALINITY SCIENCE TEAM CALL FOR WORK THAT EXPLOITS NASA SATELLITE MEASUREMENTS TO INVESTIGATE SSS VARIABILITY ITS INFLUENCE ON OCEAN CIRCULATION AND THE LINKAGE WITH CLIMATE AND WATER CYCLE. NASA SSS MEASUREMENTS WILL BE USED IN SYNERGY WITH OTHER SATELLITE AND IN SITU MEASUREMENTS INCLUDING SALINITY MEASUREMENTS FROM SMOS AND ARGO AS WELL AS SATELLITE MEASUREMENTS OF WIND TEMPERATURE AND SEA LEVEL ANOMALIES. RELIANCE ON THE HIGHER RESOLUTION SMAP SSS WILL HELP TO DEMONSTRATE THE VALUE OF SMAP DATA AND THEIR CONSISTENCY WITH ONGOING SMOS AND PREVIOUS AQUARIUS DATASETS.