WE PROPOSE TO ENHANCE THE GEOS-5 SUBSEASONAL TO SEASONAL (S2S) FORECAST CAPABILITIES BY INTEGRATING OCEAN BIOGEOCHEMISTRY INTO THE CURRENT FORECASTING SYSTEM. USING THE NASA OCEAN BIOGEOCHEMICAL MODEL (NOBM) ALREADY IMPLEMENTED INTO GMAO S GEOS-5 EARTH SYSTEM MODEL WE WILL DEVELOP A FORECAST SYSTEM FOR GLOBAL OCEAN BIOLOGY. THIS NEW DEVELOPMENT CAN IMPROVE OUR UNDERSTANDING OF THE SEASONAL AND INTERANNUAL CHANGES IN THE BIOLOGY RECRUITMENT OF HIGHER TROPHIC LEVELS AND IMPROVE OCEAN HEAT CONTENT REPRESENTATION IN THE OCEANS. THIS PROPOSAL DIRECTLY CONTRIBUTES TO IMPROVING THE PREDICTABILITY IN THE EARTH SYSTEM AREA CALLED IN THE MAP SOLICITATION. THE GEOS-5 AND NOBM WILL BE FORCED USING THE SEASONAL FORECAST OF ATMOSPHERIC AND OCEAN CONDITIONS DEVELOPED AS PART OF THE GMAO CORE WORK. THE FORECAST SKILLS WILL BE EVALUATED USING RETROSPECTIVE FORECASTS AND COMPARING THESE TO SATELLITE OCEAN COLOR DATA. THESE RETROSPECTIVE FORECASTS WILL BE USED TO QUANTIFY THE UNCERTAINTIES IN THE FORECAST OF OCEAN BIOGEOCHEMISTRY AT LEAD TIMES FROM WEEKS TO 9-MONTHS. A FOCUS OF THIS STUDY WILL BE IN ASSESSING THE SKILLS OF THIS FORECAST IN PREDICTING THE OCCURRENCE OF EL NI O SOUTHERN OSCILLATION EVENTS ON PHYTOPLANKTON CONCENTRATION IN THE PACIFIC OCEAN AS WELL AS THE PHYSICAL AND NUTRIENT CONDITIONS LEADING TO THESE EVENTS. THIS EFFORT CAN POTENTIALLY ASSIST IN UNDERSTANDING AND FORECASTING BIOLOGICAL CONDITIONS RELATED TO COMMERCIAL FISHERIES IMPROVE FORECASTING OF TEMPERATURE AND HEAT CONTENT IN THE OCEANS AND HELP GUIDE NEW NASA FIELD PROGRAMS.