RECOGNIZING THE IMPORTANCE OF SATELLITE SEA SURFACE SALINITY (SSS) DATA AND THE NEED FOR A CONSISTENT CONTINUOUS LONG-TERM HIGH QUALITY HIGH-RESOLUTION SSS DATASET FOR OCEAN RESEARCH AND APPLICATIONS THIS PROJECT SEEKS TO BUILD SUCH A DATASET FROM MULTI-SATELLITE MEASUREMENTS. THE WORK WILL REQUIRE ONGOING VALIDATION AND VERIFICATION OF THE SATELLITE DATA TO PROVIDE CONSISTENCY ACROSS TIME AND SPACE SCALES AS WELL AS DEVELOPMENT OF ALGORITHMS FOR STITCHING TOGETHER DATA FROM DIFFERENT SATELLITES. THE UNIVERSITY OF HAWAII TEAM HAS DEMONSTRATED THE CAPABILITY TO GENERATE HIGH-QUALITY GRIDDED SSS PRODUCTS FROM AQUARIUS DATA WITH UNCERTAINTY ESTIMATES. IN COLLABORATION WITH RESEARCHERS AT REMOTE SENSING SYSTEMS (RSS) THE PROPOSED PROJECT SEEKS TO EXPAND THIS WORK ADDING SSS DATA FROM THE SMAP SATELLITE. SPECIFIC OBJECTIVES ARE AS FOLLOWS: 1. PROVIDE A COMPREHENSIVE ERROR ANALYSIS OVER A FULL RANGE OF TEMPORAL/SPATIAL SCALES RESOLVED BY AQUARIUS/SMAP INCLUDING SPURIOUS TRENDS AND TIME-DEPENDENT BIASES TO OPTIMIZE THE UTILITY OF THE DATA FOR SCIENTIFIC RESEARCH AND TO REMOVE ANY SPURIOUS DRIFTS AND JUMPS. THIS ALSO INVOLVES SATELLITE-TO-SATELLITE INTER-COMPARISON BASED ON THE OVERLAP PERIOD IN APRIL-JUNE 2015. 2. PRODUCE A CONSISTENT LONG-TERM SSS DATA RECORD FROM MULTI-SATELLITE MEASUREMENTS. THIS ALSO INCLUDES IDENTIFICATION CHARACTERIZATION AND MINIMIZATION OF RANDOM ERRORS AND SYSTEMATIC BIASES IN THE DERIVED PRODUCTS TO HELP USERS ESTABLISH UNCERTAINTY LEVELS AND UNDERSTAND IF THE DATA SETS ARE SUITABLE FOR THEIR APPLICATIONS. THE DATA PRODUCTS CREATED DURING THE STUDY WILL ALSO BE USED TO INVESTIGATE OUTSTANDING SCIENTIFIC QUESTIONS IN TWO SPECIFIC REGIONS. ONE REGION IS THE MARITIME CONTINENT WHERE FRESHWATER FLUXES ARE CRITICALLY IMPORTANT FOR WATER MASS FORMATION AND POTENTIALLY IMPACT AIR-SEA INTERACTION. THE REGION IS IMPORTANT FOR INTRA-SEASONAL MONSOON AND INTER-ANNUAL VARIABILITY; HOWEVER IN-SITU AND WELL-CALIBRATED SATELLITE-BASED MEASUREMENTS ARE SCARCE. THE MERGED SSS DATA SET WILL BE EXAMINED IN ITS ACCURACY AND APPROPRIATENESS FOR STUDYING SURFACE SALINITY IN THE MARGINAL SEAS FOCUSING ON THE UPPER OCEAN FRESHWATER BUDGET. THE SPURS-2 REGION IN THE EASTERN TROPICAL PACIFIC WILL ALSO PRESENT A CASE STUDY INCLUDING AN INTENSE IN-SITU OBSERVATION PERIOD FOR WHICH THE SATELLITE SSS RECORD CAN PROVIDE THE LONGER TERM CONTEXT OF THE LARGE-SCALE SSS VARIABILITY AND THE RAPIDLY VARYING FRONTAL FEATURES. THE PROPOSED WORK RESPONDS DIRECTLY TO THE NASA SOLICITATION OBJECTIVES IN THREE SPECIFIC WAYS. FIRST THE PROJECT WILL CONTRIBUTE TO THE RESEARCH THEME 3: EVALUATION AND IMPROVEMENT OF AQUARIUS AND SMAP SSS PRODUCTS AND TO WORK TO ASSURE THE CONTINUITY AND CONSISTENCY OF THE SSS PRODUCTS ACROSS THE TWO MISSIONS. BY INVESTIGATING THE MAGNITUDE AND VARIABILITY OF THE FRESHWATER FLUXES FROM THE INDONESIAN SEAS TO THE INDIAN OCEAN USING SATELLITE SSS AND OTHER SATELLITE AND IN-SITU DATA THE PROPOSED PROJECT WILL CONTRIBUTE TO THE RESEARCH THEME 1 EXPLOITATION OF NASA SATELLITE SSS MEASUREMENTS TO INVESTIGATE SSS VARIABILITY ITS INFLUENCE ON OCEAN CIRCULATION AND THE LINKAGE WITH CLIMATE AND WATER CYCLE AND THEME 2 SYNERGISTIC USE OF NASA SSS MEASUREMENTS WITH OTHER SATELLITE AND IN SITU MEASUREMENTS . RESEARCH IN THE SPURS-2 DOMAIN WILL ALSO CONTRIBUTE TO RESEARCH THEMES 1 AND 2.