TPOS Mission 7:  A new mission to the Tropical Pacific

TPOS-2024 (Mission 7) is set to launch on 10 September 2024, with two Saildrone, Inc. uncrewed surface vehicles (USV) - SD1033 and SD1090 - departing from Alameda for the eastern/central (125°W/140°W) region of the Tropical Pacific Observing System (TPOS).  Pre-mission ADCP bottom track testing and an intercomparison with an NDBC Station (Site ID: 1801593, corresponding to SD1077) will be conducted as the drones depart.  

The official mission began October 30, 2024 at 00:00 UTC when the drones arrive at their first waypoint near 10°N, 125°W.  The 112-day mission will begin with a meridional transect south to ~0°N 125°W, and then a transect west along the equator to 140°W, where a coordinated frontal study will be performed with a University of Washington (UW) Seaglider, an underwater profiling glider deployed and operated from the MOTIVE (Mixing belOw Tropical Instability waVEs) cruise by Katie Kohlman (UW School of Oceanography).  Keeping a separation distance of ~5-20 km, while transecting thousands of kilometers, the drones will provide both high resolution and widespread coverage of important air-sea interactions in this key region of the tropical Pacific.  With a hope that these missions can be repeated sufficiently frequently to capture the large-scale variations in the air-sea fluxes (and carbon dioxide uptake and outgassing in particular), we refer to these as GO-USV transects.

Both drones will have the core Saildrone, Inc. suite of sensors (e.g. wind, air temperature, humidity, barometric pressure, PAR, 0.5m SST), the ASVCO2 suite of biological sensors, an ADCP, solar and longwave radiometers, and additional thermistors on the hull to better resolve the temperature profile in the top 2 meters of the water column.

In addition to the GO-USV transects, each mission has also tested additional capabilities of USVs integrated within the TPOS.  For this TPOS-2024 mission, we will be testing the ability to perform a coordinated frontal study using the two saildrones and the UW Seaglider.  Katie Kohlman, graduate student at the University of Washington's School of Oceanography, is the PI and pilot for the underwater glider.

For more details about this mission, please visit the OCS Saildrone TPOS 2024 Mission Blog.