XBT Analysis - Salinity Processes

XBT observations from AX07, AX08, AX10, and AX20 are used in the analysis of data in support of the NASA SPURS (Salinity Processes in the Upper Ocean Regional Study) Project. SPURS is actively addressing the essential role of the ocean in the global water cycle by exploring the salinity maximum region in the Atlantic Ocean using oceanographic equipment and technology, including salinity-sensing satellites. Researchers are studying salinity changes that span thousands of miles simultaneously with those happening in one centimeter of water. Currently, the time-series of the salinity budget in the SPURS region is being analyzed together with data from the XBT transects and from other platforms to explore the link between large scale processes and the salinity variability in the Tropical Atlantic.

Data obtained from the Global Ocean Observing networks are of critical importance for the success of SPURS, and in particular to assess the physical processes responsible for the location, magnitude, and maintenance of the subtropical Atlantic sea surface and subsurface salinity maximum. Enhancements in the XBT network in support of SPURS included the extension XBT deployments of in high density mode in the AX07 (Fort Lauderdale - Gibraltar) and AX08 (Cape Town - New York City) transects.

Location of the AX10, AX07, AX08, and AX20 high density XBT transects (blue lines), among other components of the Ocean Observing System, overlaid on the climatological Salinity at 50 m. The SPURS region is delimited by the magenta lines.

The AX08 and AX20 transects cross the SPURS region, and the data from these transects is used to monitor and investigate the variability of the zonal current system in the Tropical Atlantic. The AX07 transect runs along the northern boundary of the SPURS region and across the North Atlantic subtropical gyre.