Lagrangian Submesoscale Experiment (LASER) shipboard measurements, northern Gulf of Mexico, January-February 2016
Funded By:
Gulf of Mexico Research Initiative
Funding Cycle:
RFP-IV
Research Group:
Consortium for Advanced Research on Transport of Hydrocarbon in the Environment II (CARTHE II)
Brian Haus
University of Miami / Rosenstiel School of Marine and Atmospheric Science
bhaus@rsmas.miami.edu
Meteorological Data, Air-Sea Fluxes, Wind, Waves, Along-track Field Observations
Abstract:
Along-track measurements made on board the R/V Walton Smith as part of the LASER experiment during January-February 2016 in the northern Gulf of Mexico. Data includes meteorological flux measurements made from twin masts mounted on the bow of the R/V Walton Smith, water surface elevation measurements made from an array of Ultrasonic Distance Meters, and standard ship-board data provided from the R/V Walton Smith UDAS.
Suggested Citation:
Brian Haus. 2017. Lagrangian Submesoscale Experiment (LASER) shipboard measurements, northern Gulf of Mexico, January-February 2016. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7S75DRP
Publications:
Purpose:
The purpose of this data set is to capture the general atmospheric surface layer conditions (in the context of the R/V Walton Smith) during the entirety of the LASER campaign.
Data Parameters and Units:
The data table provided is an M x N array where M is the number of time stamps and N is the total number of parameters outputted for each time stamp. The parameter and units of each column, Ni, are reproduced below as ROWS: N1: Serial Time Stamp, UTC days since January 0, 0000 N2: Latitude, Decimal Degrees N3: Longitude, Decimal Degrees N4: Velocity over ground Northward, m/s N5: Velocity over ground Eastward, m/s N6: Vessel Heading, deg. True CW from North N7: Bow freeboard, m N8: Air Temp, degC N9: Relative Humidity, arb N10: Air Pressure, mb N11: Water Temp, degC N12: Heading rel. to Wind Direction Flag, integer N13: mean U at anemometer, m/s N14: mean wind direction, deg. True CW from North N15: air density, kg/m3 N16: COARE 3.5 UN10, m/s N17: COARE 3.5 Ustar, m/s N18: COARE 3.5 CDN10, arb N19: Eddy Covariance UN10, m/s N20: Eddy Covariance Ustar, m/s N21: Eddy Covariance CDN10, arb N22: Along-stream wind stress, N/m2 positive is down N23: Across-stream wind stress. N/ms positive is right N24: Stability parameter, arb N25: Monin-Obhukov Length, m N26: COARE 3.5 Temperature at 10 m, degC N27: COARE 3.5 specific humidity at 10 m, arb N28: COARE 3.5 relative humidity at 10 m, arb ** COLUMNS N12-N28 are repeated 5 additional times, one for each anemometer ** N114: Hs, [m] starboard UDM N115: Hs, [m] starboard-center UDM N116: Hs, [m] center UDM N117: Hs, [m] port-center UDM N118: Hs, [m] port UDM
Methods:
All of the data were processed using a 10 minute averaging interval (for means, fluxes, significant wave height, etc.). Each 10 minute segment was passed through several quality control measures and represents data that: did not experience a change in heading > 40 degrees during the 10 minutes, did not observe wind coming from the aft quadrants of the ship, and did not experience any data interruptions longer than 30 seconds. All raw data was sampled at 20 Hz and then subsampled to 16 Hz for processing. All winds have been motion corrected and adjusted to account for vessel translation. Before motion correction, all data were passed through a despiking routine to remove outlier data. The heading relative to wind direction flag is defined as either 0, 1, or 2. 0 indicates that the wind is coming from within 20 degrees of the vessel heading. 1 indicates the wind is coming from the starboard quarter out to 90 degrees off the starboard beam. 2 indicates the same, but for the port side of the vessel.
Instruments:
The meteorological masts were mounted on the starboard and port prows on the bow of the R/V Walton Smith (a SWATH vessel). Each mast was equipped with a vertical profile of anemometers. The port tower is #1 and the starboard tower is #2. The anemometers are coded from bottom to top of the profile 1-3. The 1 and 2 anemometers on both towers were RM Young 3D sonic anemometers. The 3 anemometers on each tower were Campbell Scientific IRGASONs. The UDMs were arranged with one sensor on each prow, and then 3 sensors arranged in a triplet configuration on a centerline truss mounted in between the two prows and extending ~1 m forward of the furthest edge of the prows. 6-degree vessel motion was acquired from a motion pack fastened to a bench in the R/V Walton Smith scientific lab. A GPS and magnetometer (1 Hz) were also deployed and used for all of the data processing. All systems were synced using a local NTP server.