IN THE PROPOSED WORK WE WILL FOCUS ON A BALANCED MIX OF RETRIEVAL-RELATED IMPROVEMENTS OF THE OCO-2/3 SIF DATA-PRODUCTS STUDIES TO BETTER INTERPRET AND EXPLOIT ITS DEPENDENCE ON THE SUN-SENSOR GEOMETRY AND TO USE THE GROWING TIME-SERIES OF OCO-2 SIF TO DETERMINE PRIMARY MODES OF GPP SEASONAL AND INTER-ANNUAL VARIABILITY USING STATISTICAL TOOLS. TOWARDS THAT GOAL WE IDENTIFIED FIVE WELL DEFINED OBJECTIVES WHICH ARE CRUCIAL TO IMPROVE THE OCO-2 SIF DATA QUALITY ENHANCE THE SCIENTIFIC OUTPUT AND MAKE USE OF THE OCO-2 TIME-SERIES.