Raw temperature, salinity and biogeochemical profile data from Electro-Magnetic Autonomous Profiling Explorer (EM-APEX) floats collected aboard R/V Walton Smith cruise WS17121 in the northern Gulf of Mexico from 2017-05-02 to 2017-05-17

This dataset contains raw temperature, salinity, and biogeochemical profile data acquired from Electro-Magnetic Autonomous Profiling Explorer (EM-APEX) floats deployed via U. Miami R/V Walton Smith cruise WS17121 in the northern Gulf of Mexico from 2017-05-02 to 2017-05-17. Period of the record is for the first 10 days of operation during a cold front passage. The first day of record for each float ranges from May 2, 2017, to May 7, 2017. Technology for measuring subsurface ocean currents (including temperature and salinity) is available using the EM-APEX recently developed by Teledyne Webb Research and the University of Washington. The float acquires temperature and salinity profiles using a Seabird sensor. This EM-APEX profiling float platform was equipped with chemical and bio-optical sensors: Aanderaa Optode sensor measuring dissolved oxygen and the WET Labs ECO Puck sensor which combines measurement of chlorophyll fluorescence (proxy of phytoplankton abundance), measurement of backscatter (as proxy of particle concentration) and colored dissolved organic matter (CDOM) fluorescence (incl. fluorophoric oil components). Sampling rates were changed by updating mission profiles from continuous to profiling modes between specific depths by changing the piston counts on the missions via Iridium remote sensing when the float reaches the free surface. Related raw current velocity profile data is available under GRIIDC Unique Dataset Identifier (UDI): R5.x275.000:0003 (DOI: 10.7266/59DNJ7BW).