Scripps Institution of Oceanography
Physical Oceanography Research Division
La Jolla, California
Supporting Stations: ARSV Laurence M. Gould
Research Locations: Drake Passage
The objective of the eXpendable BathyThermograph / eXpendable Conductivity Temperature Depth (XBT/XCTD) program is to measure the seasonal to interannual variability of upper-ocean temperature and geostrophic transport through the Drake Passage. Closely spaced XBT (temperature) and XCTD (salinity) 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:
On selected Drake transit cruises of the LMG, staff techncians deploy XBT and XCTD sensors and collect the data they send back to the vessel during their descent. Approximately 70 XBTs (eXpendable BathyThermographs) are dropped by Scripps' automatic launcher at pre-specified locations identified by shipboard GPS. Approximately 12 XCTD (eXpendable Conductivity Temperature Depth) probes are dropped at specified locations during the same transects. Staff technicians load the launcher and collect salinity samples which are used to calibrate the XCTD and underway thermosalinograph (TSG) data. One project participant will deploy to a port call to install new software and upgrade existing instrumentation.