THE PRIMARY GOAL OF THE EXPORTS PROCESSES IN THE OCEAN FROM REMOTE SENSING (EXPORTS) PROGRAM IS TO DEVELOP A PREDICTIVE MECHANISTIC UNDERSTANDING OF THE EXPORT AND FATE OF FIXED CARBON (C) FROM GLOBAL OCEAN PRIMARY PRODUCTION. INHERENT IN THESE PREDICTIONS IS THE NEED TO REDUCE UNCERTAINTIES IN C EXPORT AND TO DEVELOP MODELS THAT FACILITATE FUTURE C EXPORT PREDICATIONS ACROSS A VARIETY OF SPATIAL AND TEMPORAL SCALES. THE FIRST PHASE INCLUDES LARGE-SCALE FIELD CAMPAIGNS USING REMOTE SENSING AUTONOMOUS PLATFORMS AND PROCESS-LEVEL STUDIES TO BUILD UPON CURRENT KNOWLEDGE. AS SUCH CRITICAL COMPONENTS TO THE EXPORTS PROGRAM ARE QUANTITATIVE MEASUREMENTS OF SINKING PARTICLE FLUXES AND THEIR ATTENUATION AT SCALES SIMILAR TO THE PHYSICAL AND BIOLOGICAL PROCESSES THAT INFLUENCE FIXED C EXPORT. WE PROPOSE USING THE PARTICLE-REACTIVE TRACER THORIUM-234 (HALF-LIFE = 24. 1 D) TO QUANTIFY THE SPATIO-TEMPORAL VARIABILITY IN PARTICLE FLUX FROM THE WELL-LIT SURFACE LAYER AND ITS ATTENUATION WITH DEPTH BELOW. THE DISEQUILIBRIUM IN 234TH FROM ITS SOLUBLE PARENT URANIUM-238 PROVIDES QUANTITATIVE INFORMATION ON WHERE PARTICLE EXPORT AND REMINERALIZATION OCCURS. WE WILL COLLECT AN UNPRECEDENTED SET OF 234TH PROFILES ( 60) TO OBTAIN A 3D TIME-SERIES OF PARTICLE EXPORT AND REMINERALIZATION RATES OVER MESO- (~ 10 KM) AND SUBMESOSCALES (~ 1 KM).