Abstract:

As part of CARTHE's SPLASH (Submesoscale Processes and Lagrangian Analysis on the SHelf) experiment, current observations were obtained from a variety of instruments in the Louisiana Bight, northern Gulf of Mexico. On 27 April 2017, between 17:00 UTC and 22:00 UTC, six types of measurements at various depths were taken, which in combination provide the near-surface current shear in the area 89°38.29' W - 89°41.25' W and 29°9.83' N - 29°10.65' N. This dataset contains the current measurements obtained from (1) thin bamboo plates at 0.9 cm depth; (2) an undrogued LASER-style drifter at 1.8 cm depth; (3) a drogued LASER-style drifter at 30 cm depth; (4) polarimetry valid at 0.8 cm - 4.9 cm depth; (5) the ADCP mounted on the autonomous REMUS for depths between 0.18 m and 3.77 m; and (6) the bottom-mounted ADCP from the research vessel Walton Smith for depths between 4 m and 13.5 m. In addition, the velocities obtained from a theoretical Stokes drift profile are provided for the top 1 m in steps of 0.1 cm.

Suggested Citation:

Nathan Laxague. 2018. Near-Surface Current Shear from Multiple Instruments, Submesoscale Processes and Lagrangian Analysis on the SHelf (SPLASH), northern Gulf of Mexico, 27 April 2017. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7ZW1JC0

Publications:

Laxague, N. J. M., Özgökmen, T. M., Haus, B. K., Novelli, G., Shcherbina, A., Sutherland, P., … Molemaker, J. (2018). Observations of Near-Surface Current Shear Help Describe Oceanic Oil and Plastic Transport. Geophysical Research Letters. doi:10.1002/2017gl075891

Purpose:

In order to better understand the physical processes relevant to the transport of oil and marine debris, the current vector profile (defined within 1 cm of the air-sea interface) was observed.

Data Parameters and Units:

Current magnitude [m/s] and direction [deg] as a function of depth [m] from three types of tracked drifting instruments, two types of in-water acoustic current meters, one remote sensing instrument, and one theoretical Stokes drift profile. k [rad/m], S [m^3], 5th percentile, 95th percentile

Instruments:

plates - thin bamboo plates; 5 consecutive trials given in successive rows undrogued - drifter without subsurface drogue drogued - drifter with subsurface drogue polarimeter - currents obtained from short wave fields [Laxague, N. J. M., Haus, B. K., Ortiz-Suslow, D. G., Smith, C. J., Novelli, G., Dai, H., Özgökmen, T., and Graber, H. C. (2017). Passive Optical Sensing of the Near-Surface Wind-Driven Current Profile. Journal of Atmospheric and Oceanic Technology, vol. 34, no. 5, pp. 1097-1111. doi: 10.1175/JTECH-D-16-0090.1] Stokes - Stokes drift profile computed from shipboard wave gauge array REMUS - ADCP mounted on autonomous underwater vehicle WH1200kHz - 1200 kHz WorkHorse ADCP mounted on R/V F.G. Walton smith (research vessel)

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