IGF::OT::IGF THIS CONTRACT IS A RESULT OF A NASA RESEARCH ANNOUNCEMENT AWARD. THE INVESTIGATION TO BE CONDUCTED UNDER THIS CONTRACT IS A CONTINUATION OF THE GMI INVESTIGATION THAT WAS FUNDED THROUGH ROSES 2013: PHYSICAL OCEANOGRAPHY SOLICITATION. THE OBJECTIVE OF THE INVESTIGATION IS TO CONTINUE THE PRODUCTION, VALIDATION, AND UTILIZATION OF THE GEOPHYSICAL RETRIEVALS FROM THE GLOBAL PRECIPITATION MEASUREMENT MISSION (GPM) MICROWAVE IMAGER (GMI), WHICH WAS LAUNCHED IN FEBRUARY 2014. THE GMI OBSERVATIONS ARE BEING USED TO PRODUCE SETS OF FIVE AIR-SEA (AS) VARIABLES, ALL OF WHICH ARE CLASSIFIED AS ESSENTIAL CLIMATE VARIABLES (ECV) BY THE GLOBAL OBSERVING SYSTEM FOR CLIMATE (GCOS): 1. SEA-SURFACE TEMPERATURE (SST, C), (MICROWAVE THROUGH-CLOUD RETRIEVALS) 2. NEAR-SURFACE OCEAN WINDS (M/S) 3. TOTAL WATER VAPOR ABOVE THE OCEAN (MM) 4. TOTAL CLOUD WATER ABOVE THE OCEAN (MM) 5. SEA-SURFACE RAIN RATE (MM/HR) HEREIN, THESE DATA PRODUCTS ARE REFERRED TO AS AS-ECV. THE GMI AS-ECV HAVE BEEN INTERCALIBRATED WITH SIMILAR RETRIEVALS FROM 3 OTHER MICROWAVE IMAGERS (TMI, AMSR-2, AND WINDSAT) AND ARE NOW AN ESSENTIAL COMPONENT OF THE 30-YEAR AS CLIMATE DATA RECORD (AS-CDR). GMI HAS AN ADVANCED ON-BOARD CALIBRATION SYSTEM, AND ITS INCLINED ORBIT PROVIDES PRECISE COLLOCATIONS WITH THE OTHER MICROWAVE IMAGERS (MI). ACCORDINGLY, WE EXPECT GMI WILL BE THE ABSOLUTE CALIBRATION REFERENCE FOR THE AS-CDR FOR THE NEXT 1 TO 2 DECADES. THE AS-ECV FROM GMI AND ALL THE OTHER MIS ARE FREELY AVAILABLE VIA THE INTERNET. THIS EFFORT PROPOSES THE FOLLOWING IMPROVEMENTS TO THE GMI PROCESSING ALGORITHMS, WHICH WILL BE IMPLEMENTED TOWARDS THE END OF THE INVESTIGATION: 1. MITIGATION OF SUN GLITTER CONTAMINATION 2. FURTHER MITIGATION OF RADIO FREQUENCY INTERFERENCE 3. ASSIGNMENT OF ERROR BARS TO AS-ECV 4. EXTENDING THE AS-ECV CLOSER TO LAND (EXPERIMENTAL) A UNIQUE FEATURE OF GMI (AND ITS PREDECESSOR TMI) IS THAT IT SAMPLES THE ENTIRE 24-HOUR DIURNAL CYCLE OF AIR-SEA INTERACTIONS. THE PROPER CHARACTERIZATION OF DIURNAL VARIABILITY IS ESSENTIAL TO UNDERSTANDING THE PLANET'S MOST FUNDAMENTAL HARMONIC. THE ACCURATE REPRESENTATION OF THE COUPLING OF THE OCEANS AND ATMOSPHERE CONTINUES TO BE A MAJOR CHALLENGE FOR CLIMATE MODELS. THE AS-CDR IS PARTICULARLY WELL SUITED FOR STUDYING THESE ISSUES BECAUSE IT PROVIDES UNIQUE INFORMATION ON THE AIR-SEA EXCHANGE OF MOMENTUM, ENERGY, AND MOISTURE OVER THE LAST 3 DECADES.