Abstract:

This dataset contains raw current velocity 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 is available using the EM-APEX sensors recently developed by Teledyne Webb Research and the University of Washington. Velocity measurements obtained from electromagnetic current sensor pairs. 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 temperature, salinity and biogeochemical profile data are available under GRIIDC Unique Dataset Identifier (UDI): R5.x275.000:0002 (DOI: 10.7266/7QQF9969).

Suggested Citation:

Shay, Lynn; Brewster, Jodi; Jaimes, Benjamin; Rudzin, Johna; Fennel, Katja; Gordon, Chris. 2020. Raw current velocity 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: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/59DNJ7BW

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 impact biochemistry and hydrocarbon dispersion.

Data Parameters and Units:

Time [Time of profile in UTC]; Date [Date of profile in YYYY-MM-DD]; Latitude [degrees_north]; Longitude [degrees_west]; Pressure [Raw pressure as measured by ADCP, dbars]; U1 [Raw geomagnetic eastward velocity component from ADCP electrode Pair #1, ms-1]; V1 [Raw geomagnetic northward velocity component from ADCP electrode Pair #1, ms-1]; Verr1 [Standard velocity error from ADCP electrode pair #1, ms-1]; U2 [Raw geomagnetic eastward velocity component from ADCP electrode Pair #2, ms-1]; V2[Raw geomagnetic northward velocity component from ADCP electrode Pair #2, ms-1]; Verr2 [Standard velocity error from ADCP electrode pair #2, ms-1]; flag_vel [Flagged data points for velocity profiles, 0: good data; 1: bad data]; dp_dt [Float Ascension Rate, ms-1]; RotP [Float Rotation Period, Sec].

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