2016-2017 USAP Field Season
The Drake Passage high-density XBT program
Dr. Janet Sprintall
Scripps Institution of Oceanography
Project Web Site:
Supporting Stations: ARSV Laurence M. Gould
The objective of the eXpendable BathyThermograph (XBT) program is to measure the seasonal to interannual variability of upper-ocean temperature and geostrophic transport through the Drake Passage. Closely spaced XBT (temperature) measurements are collected underway on six to eight Drake Passage crossings of the ARSV Laurence M. Gould (LMG) per year. The project has been ongoing since 1996. With the multi-year time series, researchers have observed substantial variability in circulation, transport, and water properties on time scales from seasonal to interannual, and spatial scales from mesoscale eddies to the Antarctic Circumpolar Current cores.
Field Season Overview
ARSV Laurence M. Gould personnel and passenger volunteers will hand-launch approximately 70 XBTs at predetermined locations on each of six Drake Passage crossings of the LMG. Salinity bottle samples will be collected at various sites. This bottle data will be used to calibrate the underway thermosalinograph (TSG) data. One project participant may visit the vessel every other year while it is in port at Punta Arenas, Chile for system maintenance.