NASAS SOIL MOISTURE ACTIVE PASSIVE (SMAP) SATELLITE HAS BEGUN TO MAKE GLOBAL MAPS OF SOIL MOISTURE A KEY RESERVOIR OF THE WATER CYCLE THAT IMPACTS WEATHER AND CLIMATE AND AGRICULTURAL PRODUCTIVITY. WHILE MUCH OF THE FOCUS OF THE MISSION UP TO THIS POINT IN TIME HAS BEEN ON SOIL MOISTURE RETRIEVAL SMAP MEASUREMENTS ARE ACTUALLY EQUALLY SENSITIVE TO THE AMOUNT OF VEGETATION COVERING EARTHS TERRESTRIAL SURFACE. INSTEAD OF VIEWING THE EFFECT OF VEGETATION AS NOISE THAT MUST BE REMOVED IN ORDER TO RECOVER THE SOIL MOISTURE SIGNAL WE PROPOSE TO USE SMAP TO ALSO RETRIEVE INFORMATION ABOUT THE VEGETATION ITSELF. OUR LONG TERM GOAL IS TO DETERMINE HOW AGRICULTURAL ECOSYSTEMS WILL BE AFFECTED BY GLOBAL ENVIRONMENTAL CHANGE AND THE FEEDBACKS BETWEEN AGRICULTURAL ECOSYSTEMS AND THE ATMOSPHERE. OUR OBJECTIVE IN THIS PROPOSAL IS TO DEVELOP A NEW SATELLITE REMOTE SENSING PRODUCT THAT CAN BE USED TO MONITOR THE PRODUCTIVITY OF AGRICULTURAL ECOSYSTEMS. WE HYPOTHESIZE THAT SMAP CAN BE USED TO ACCURATELY DETERMINE THE TOTAL AMOUNT OF BIOMASS ACCUMULATED IN AGRICULTURAL ECOSYSTEMS WITH AN UNPRECEDENTED TEMPORAL RESOLUTION. OUR RATIONALE FOR THIS PROPOSAL IS THAT A SMAP PRODUCT WOULD HAVE DISTINCT ADVANTAGES OVER EXISTING VISIBLE/NEAR IR SATELLITE PRODUCTS THAT ARE CURRENTLY USED TO MONITOR AGRICULTURAL PRODUCTIVITY. WE ARE UNIQUELY QUALIFIED TO CONDUCT THIS INVESTIGATION. PI HORNBUCKLE IS AN EXPERT IN PASSIVE REMOTE SENSING OF LAND AT L BAND. CO I VANLOOCKE HAS EXPERTISE IN THE MODELING OF AGRICULTURAL ECOSYSTEMS. COLLABORATORS BERNACCHI AND SUYKER MAINTAIN EXTENSIVE FIELD DATA COLLECTION PROGRAMS IN IMPORTANT AGRICULTURAL REGIONS. WE HAVE TWO SPECIFIC OBJECTIVES IN THIS PROPOSAL. 1. GENERATE A NEW SMAP PRODUCT THAT QUANTIFIES THE ACCUMULATED ABOVE GROUND DRY AND FRESH BIOMASS AND ABOVE GROUND NET PRIMARY PRODUCTION NPPA OVER TIME DURING THE LOCAL GROWING SEASON FOR MAJOR AGRICULTURAL REGIONS OF THE WORLD. 2. DETERMINE THE VALUE OF THE B PARAMETER WHICH RELATES (A QUANTIFICATION OF THE EFFECT OF VEGETATION ON SOIL MOISTURE RETRIEVAL) TO THE COLUMN DENSITY OF WATER IN VEGETATION TISSUE COMMONLY CALLED V W C FOR MAJOR AGRICULTURAL REGIONS OF THE WORLD. THIS PROPOSAL IS INNOVATIVE IN TWO WAYS. FIRST WE WILL PRODUCE VALIDATED SATELLITE FOOTPRINT SCALE VALUES FOR B AND WHICH HAS SO FAR NOT BEEN ACCOMPLISHED BY ANY GROUP. SECOND WE WILL COMBINE IN SITU MEASUREMENTS OF VEGETATION WITH A STATE OF THE ART CROP MODEL TO BEST CHARACTERIZE SATELLITE FOOTPRINT SCALE VEGETATION BIOMASS IN AGRICULTURAL REGIONS. THE EXPECTED OUTCOME OF THIS PROPOSAL IS A NEW SATELLITE PRODUCT THAT OFFERS UNIQUE INFORMATION WHICH WILL COMPLEMENT EXISTING METHODS THAT ARE CURRENTLY USED TO MONITOR AGRICULTURE FROM SPACE. OUR FINDINGS WILL ALSO PROVIDE THE SMAP SCIENCE TEAM WITH NEW INFORMATION ON HOW VEGETATION AFFECTS THE RETRIEVAL OF SOIL MOISTURE THAT CAN BE USED TO IMPROVE THE SMAP SOIL MOISTURE PRODUCTS. FINALLY OUR WORK WOULD INCREASE THE USE OF SMAP DATA AND HELP NASA ACCOMPLISH ITS GOAL OF QUANTIFYING GLOBAL PRODUCTIVITY BIOMASS CARBON FLUXES AND CHANGES IN LAND COVER.