Abstract:

Scientist onboard the Gulf of Mexico Ecosystems and Carbon Cycle cruise (GOMECC-3) around the shelf of the Gulf of Mexico from 2017-07-18 to 2017-08-21 released 25 GPS-equipped biodegradable CARTHE-style drifters to survey the ocean currents in the Gulf of Mexico. The drifters are drogued at 50 cm and reported their positions nominally every 5 minutes. This dataset contains the raw GPS data along with the launch log. It also contains a filtered version of the data (using GMT filter1d) with positions recorded every 15 minutes. The drifters transmitted their positions from 2017-07-22 to 2017-09-17. The main objective of GOMECC-3 was to perform a large-scale survey of ocean acidification trends and dynamics in the Gulf of Mexico on NOAA ship Ronald H. Brown. GOMECC-3 chief scientist was Leticia Barbero. Cruise ID: GOMECC-3.

Suggested Citation:

Olascoaga, Maria Josefina. 2019. Drifters released during the Gulf of Mexico Ecosystems and Carbon Cycle (GOMECC-3) cruise in the Gulf of Mexico from 2017-07-22 to 2017-09-17. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7G44NW5

Purpose:

Launched from a cruise of opportunity, these drifters add insight into transport on the shelf regions of the Gulf of Mexico, include cross-shelf and along-shore movement.

Data Parameters and Units:

Files “gomecc3_spot_xml_data*” contain the drifter location. Unique message id (column 1), spot id number (column 2), drifter id string (like C_XXXX, XXXX=4 digit integer, column 3), date and time (yyyy-mm-ddTHH:MM:SS.000Z, column 4), seconds from epoch in GMT (column 5), latitude (decimal degrees, column 5), longitude (decimal degrees, column 7), message type (column 8), battery state (column 9). When everything is working as designed, a data record should appear every 5 minutes. If the SPOT unit cannot get a position fix, it still sends a message with a time stamp, but the lat/lon appear as -99999.0. The "filtered" data was filtered in time with GMT filter1d and interpolated to 15-minute intervals. File “spot_drifter_deployment_log_GOMECC3.prn” contain the log information. Deployment (always 'GOMECC3', column 1), ship (always 'RB' for NOAA ship Ronald H. Brown, column 2), waypoint (integer, column 3), line (integer, column 4), station (column 5), SPOT ID (C_xxxx, column 6), drifter type (always 'CARTHE', column 7), launch date (yyyy-mm-dd, column 8), launch time UTC (HH:MM:SS, column 9), longitude (decimal degree, column 10), latitude (decimal degree, column 11), end date (yyyy-mm-dd) of the entire record deemed credible (column 12), end time (HH:MM:SS) of the entire record deemed credible (column 13), notes on location and failures (column 14).

Individual Files: