RESERVOIR FLOW REGULATION REPRESENTS THE MOST INTENSIVE ALTERATION OF THE WATER CYCLE INTRODUCED BY HUMANS. INFORMATION ABOUT RESERVOIR STORAGE VARIATIONS AND EVAPORATION LOSSES ARE BOTH IMPORTANT AND DIFFICULT TO ACQUIRE. THESE CONSTRAINTS MAKE IT CHALLENGING TO UNDERSTAND THE ROLE OF RESERVOIRS IN THE HYDROLOGICAL CYCLE AND TO MITIGATE EVAPORATIVE LOSSES FOR PRECISE WATER MANAGEMENT. THUS A GLOBAL RESERVOIR PRODUCT IS NEEDED TO ANSWER THE FOLLOWING SIGNIFICANT SCIENCE QUESTIONS: 1) WHAT IS THE LONG TERM TREND OF RESERVOIR STORAGE AT LOCAL REGIONAL AND GLOBAL SCALES? HOW SIGNIFICANT ARE THE SEASONAL RESERVOIR STORAGE VARIATIONS AS COMPARED TO OTHER TERRITORIAL STORAGE TERMS? 2) WHAT IS THE TREND OF RESERVOIR EVAPORATION LOSS? AND WHAT IS (ARE) THE KEY CHARACTERISTIC(S) THAT THEY HAVE IN COMMON CLIMATE ZONE HYDROLOGIC REGION OR OPERATION RULES? 3) TO WHAT DEGREE ARE WE CERTAIN/UNCERTAIN IN QUANTIFYING THE ROLE OF RESERVOIR STORAGE VARIATIONS AND EVAPORATION LOSS IN THE WATER BUDGET? THE DEVELOPMENT OF SATELLITE REMOTE SENSING TECHNOLOGIES HAS SHOWN A UNIQUE PROMISE FOR MONITORING LARGE RESERVOIRS FROM SPACE. HOWEVER THE REMOTELY SENSED RESERVOIR STORAGE DATA SETS ARE SO FAR VERY LIMITED (BOTH SPATIALLY AND TEMPORALLY); AND THERE ARE ONLY A FEW STUDIES USING SATELLITE REMOTE SENSING DATA TO ESTIMATE RESERVOIR EVAPORATION. TO CLOSE KEY KNOWLEDGE GAPS WE PROPOSE TO DEVELOP STATE-OF-THE-ART REMOTE SENSING ALGORITHMS FOR MONITORING RESERVOIRS BY FUSING MULTI-SATELLITE OBSERVATIONS. THE GOAL OF THIS PROPOSED PROJECT IS TO GENERATE A LONG TERM COMPREHENSIVE COHERENT AND VALIDATED GLOBAL RESERVOIR PRODUCT SERIES AT IMPROVED SPATIAL COVERAGE (AND AT IMPROVED TEMPORAL RESOLUTION). WE SHOW THAT TERRA AQUA AND SUOMI NPP OBSERVATIONS (WHEN COMBINED WITH DATA FROM OTHER SATELLITES) HAVE UNIQUE ADVANTAGES FOR GENERATING A ONE-OF-A-KIND RESERVOIR PRODUCT SERIES. SPECIFICALLY WE WILL ACHIEVE THE FOLLOWING OBJECTIVES: 1) DEVELOP A LONG TERM RESERVOIR STORAGE VARIATION PRODUCT (WITH ELEVATION AND AREA AS A BYPRODUCT) UNDER ALL-WEATHER CONDITIONS; 2) GENERATE LONG TERM RECORDS OF RESERVOIR EVAPORATION RATE AND EVAPORATION LOSS; AND 3) VALIDATE THE RESERVOIR PRODUCT SERIES AND QUANTIFY THE UNCERTAINTIES ASSOCIATED WITH THE DATASETS. TWO PARALLEL RESERVOIR DATASETS ONE ROOTED IN THE MODERATE-RESOLUTION IMAGING SPECTRORADIOMETER (MODIS) AND THE OTHER FROM VISIBLE INFRARED IMAGING RADIOMETER SUITE (VIIRS) WILL BE GENERATED IN THIS PROJECT. WE WILL FOCUS ON EVALUATING THE CONSISTENCY BETWEEN THESE TWO SETS OF RESERVOIR PRODUCTS DURING THEIR OVERLAPPING PERIOD SINCE 2011. AN ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD) MEETING THE REQUIREMENTS ESTABLISHED FOR NASA EARTH SCIENCE MISSION PRODUCTS WILL BE PREPARED AND DELIVERED. THE PROPOSED PROJECT SUPPORTS THE GOAL OF NASA'S EARTH SCIENCE RESEARCH PROGRAM DESCRIBED IN THE SOLICITATION WHICH IS "TO UTILIZE GLOBAL MEASUREMENTS TO UNDERSTAND THE EARTH SYSTEM AND INTERACTIONS AMONG ITS COMPONENTS AS STEPS TOWARD PREDICTION OF EARTH SYSTEM BEHAVIOR". THE NEWLY DEVELOPED ALGORITHM AND RESERVOIR PRODUCT DIRECTLY ADDRESSES THE PROGRAM ELEMENT ON "2.2 ALGORITHMS