THE SOUTHERN OCEAN PLAYS A DISPROPORTIONATELY LARGE IN GLOBAL CARBON CYCLING AND HAS REMAINED CHRONICALLY UNDER-SAMPLED DUE TO ITS REMOTE LOCATION AND EXTREME CONDITIONS. THE NSF AND NASA SPONSORED SOCCOM PROJECT MADE AN SIGNIFICANT EFFORT TO ADDRESS BY DEPLOYING 180 BIO-ARGO FLOATS THAT PROVIDED SUSTAINED YEAR ROUND CIRCUMPOLAR SAMPLING. THE BIO-OPTICAL FLOATS HAVE PROVIDED MEASUREMENTS OF OPTICAL BACKSCATTER AND CHLOROPHYLL FLUORESCENCE PROVIDING AN UNPRECEDENTED IN SITU ARRAY TO COMPLEMENT OCEAN COLOR REMOTE SENSING TO PROVIDE A COMPREHENSIVE 4D PICTURE THE PHYTOPLANKTON PARTICLE AND CARBON DYNAMICS FOR THE SOUTHERN OCEAN. NSF RECENTLY FUNDED SOCCOM-2 TO CONTINUE THE DEPLOYMENT OF BIO-ARGO SYSTEMS. THE PROGRAM FUNDS THE BIOGEOCHEMICAL FLOATS BUT DOES PROVIDE FUND FOR OPTICAL MEASUREMENTS (BACKSCATTER AND CHLOROPHYLL FLUORESCENCE). THIS PROPOSAL SEEKS TO 1) ACQUIRE OPTICAL SENSORS TO BE INCORPORATED INTO THE SOCCUM-2 FLOATS 2) COLLECT IN SITU CALIBRATION/VALIDATION SAMPLES (PARTICULATE ORGANIC CARBON AND HPLC-MEASURED PHYTOPLANKTON PIGMENTS) DURING FLOAT DEPLOYMENTS AND 3) CONDUCT QUALITY CONTROL ON THE DATA FROM THE DEPLOYED FLOATS.