THE WORK PROPOSED HERE WILL ENCOMPASS TWO SEPARATE BUT RELATED ITEMS, 1) THE SPATIAL AND TEMPORAL STRUCTURE AND VARIABILITY OF THE TAILS OF THE PROBABILITY DISTRIBUTION OF SEA SURFACE SALINITY (SSS) AND 2) THE IMPORTANCE OF SUBFOOTPRINT VARIABILITY (SFV). THE GOAL OF PART 1 IS AS FOLLOWS: BY EXAMINING THE PROBABILITY DISTRIBUTION OF SSS, AND PARTICULARLY THE LOWER AND UPPER TAILS OF THAT DISTRIBUTION, WE CAN COME TO BETTER UNDERSTAND THE ALL-IMPORTANT CONNECTION OF SSS TO THE PROCESSES EXTERNAL TO THE OCEAN THAT CONTROL IT AND TO THE GLOBAL WATER CYCLE. IN SHORT, WE CAN MOVE TOWARDS THE ORIGINAL GOAL OF THE AQUARIUS PROGRAM, TO USE SSS AS AN OCEANIC RAIN GAUGE. THE GOAL OF PART 2 IS: VARIABILITY WITHIN THE FOOTPRINT OF THE AQUARIUS (OR SMAP) SATELLITE HAS NOT BEEN QUANTIFIED IN A SYSTEMATIC ENOUGH WAY. IT MAY OR MAY NOT BE A STRONG CONTRIBUTOR TO MISMATCHES BETWEEN SATELLITE MEASUREMENTS AND IN SITU DATA USED FOR VALIDATION. THIS PROJECT WILL EXPLORE THE IMPORTANCE OF SFV TO SSS VALIDATION.