THE OVERALL GOAL OF THIS PROJECT IS TO DEFINE THE DEGREE TO WHICH COMBINING INFORMATION FROM TWO RECENT AND COMPLEMENTARY NASA SATELLITE SENSORS PROVIDE 1. QUANTITATIVE AND COMPELLING INFORMATION ON ECOSYSTEM FUNCTIONING AND STRUCTURE; 2. EARLY WARNING AND PREDICTION CAPABILITY FOR CARBON CYCLECLIMATE FEEDBACKS AND 3. IMPROVEMENTS IN OUR ABILITY TO RECONCILE CARBON FLUX ESTIMATES FROM A BOTTOM UP AND TOP DOWN PERSPECTIVE. WE WILL USE EARLY MISSION DATA FROM BOTH SMAP AND OCO2 TOMAKE PRELIMINARY ESTIMATES THAT WILL BECOME MORE MATURE AS LONGER TIME SERIES ACCUMULATE. SPECIFIC OBJECTIVES AND STEPS TARGETED TO ADDRESS THIS OVERALL GOAL ARE AS FOLLOWS. 1. ASSESS THE BENEFIT OF SMAP DERIVED FREEZE OR THAW AND SOIL MOISTURE STATE IN IMPROVING ESTIMATES OF ECOSYSTEM CARBON EXCHANGE AND IN EXPLAINING OBSERVED TRENDS IN ATMOSPHERIC CO2 VARIABILITY IN THE NORTHERN HIGH LATITUDES. 2. UTILIZE SMAP SOIL MOISTURE INFORMATION TO IDENTIFY DROUGHT OR WATER STRESS EVENTS AND TO EVALUATE REPRESENTATION OF ECOSYSTEM PRODUCTIVITY WITHIN LAND SURFACE MODELS DURING SUCH EVENTS. 3. RECONCILE BOTTOM UP AND TOP DOWN ESTIMATES OF TERRESTRIAL CARBON FLUXES AT A VARIETY OF SPATIAL AND TEMPORAL SCALES