GLOBAL ESTIMATION OF THE OCEAN SURFACE TURBULENT LATENT AND SENSIBLE HEAT FLUXES REQUIRES KNOWLEDGE OF SEVERAL PARAMETERS OVER THE OCEAN SURFACE INCLUDING WIND SPEED SEA SURFACE TEMPERATURE AIR HUMIDITY AND TEMPERATURE. EACH OF THESE PARAMETERS CAN AND HAVE BEEN ESTIMATED USING SATELLITE-BASED PASSIVE MICROWAVE IMAGER OBSERVATIONS. RECENT INVESTIGATIONS HAVE INCREASINGLY DEMONSTRATED A NEED TO IMPROVE UPON HERITAGE EMPIRICAL-REGRESSION BASED RETRIEVAL ALGORITHMS. IN PARTICULAR THERE IS NEED TO INCORPORATE PRIOR CONSTRAINTS TO BETTER CONDITION RETRIEVALS OF THE ATMOSPHERIC STATE THAT ARE FUNDAMENTALLY UNDERCONSTRAINED BY MICROWAVE IMAGERS. EFFORTS ARE ALSO NEEDED TO PROVIDE FLEXIBILITY TO ADDRESS SENSOR DIFFERENCES INCLUDING VIEWING GEOMETRY RESOLUTION AND CHANNEL FREQUENCIES. EACH OF THESE CONCERNS CAN BE ADDRESSED THROUGH USE OF A VARIATIONAL INVERSION APPROACH (1DVAR). RECENT EFFORTS HAVE RESULTED IN A FLEXIBLE 1DVAR SYSTEM DESIGNED FOR THE CONSTELLATION OF PASSIVE MICROWAVE IMAGERS. HOWEVER EFFORTS ARE REQUIRED TO EXTEND THIS TO ADDRESS ERRORS RELATED TO A LACK OF WATER PROFILE INFORMATION AND TO ESTIMATE SURFACE METEOROLOGY INCLUDING AIR HUMIDITY AND TEMPERATURE.