Abstract:

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).

Suggested Citation:

Shay, Lynn; Brewster, Jodi; Jaimes, Benjamin; Rudzin, Johna; Fennel, Katja; Gordon, Chris. 2020. 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. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/7QQF9969

Publications:

Shay, L. K., Brewster, J. K., Jaimes, B., Gordon, C., Fennel, K., Furze, P., … He, R. (2019). Physical and Biochemical Structure Measured by APEX-EM Floats. 2019 IEEE/OES Twelfth Current, Waves and Turbulence Measurement (CWTM). doi:10.1109/cwtm43797.2019.8955168

Purpose:

Given the passage of a strong atmospheric front in May 2017, these data were used in an initial evaluation of the state-of-the-art float and its response to strong wind-driven currents. This float technology enables investigators to look more closely at the upper ocean response to strong forcing events that impacts biochemistry and hydrocarbon dispersion.

Data Parameters and Units:

Latitude [degrees], Longitude [degrees], Pressure [dbar], Date [YYYY-MM-DD], Time [UTC], Temperature [degrees Celsius], Salinity [PSU], Dissolved oxygen [umol/kg], BBB700 (raw backscatter measured at 700nm [1/m]), CDOM (Raw colored dissolved organic matter [mg/L], CHLA (chlorophyll, [mg/L]), BSig (backscatter counts, input for conversion to bbp [counts]), CSig (Raw CDOM counts, input for conversion to CDOM [counts]), FSig (Fluorescence counts, input for conversion to Chla [counts].

Instruments:

The float acquires temperature and salinity profiles using a Seabird sensor. This APEX-EM 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).

Individual Files: