SWOT Postlaunch Oceanography Field Campaign Shipboard CTD and Water Sample Data

The SWOT Postlaunch Oceanography Field Campaign Shipboard CTD and Water Sample Data collection provides the conductivity, temperature and depth (CTD) measurements and water sample measurements from shipboard instruments deployed by the Surface Water and Ocean Topography (SWOT) postlaunch field campaign. The SWOT satellite mission launched in late 2022 and underwent a calibration and validation (cal/val) phase in 2023. As part of cal/val, an array of oceanographic instruments was deployed at a site 300 km offshore of California. Shipboard data come from four research cruises on the Bold Horizon and the Sally Ride, with different time spans ranging from February 23, 2023 to November 2, 2024. These measurements were used to adjust the calibrations of mooring CTD sensors (deployed in the same field campaign) to a common and well-calibrated reference, to enable the calculation of steric height for SWOT cal/val analyses.

Most, but not all of the CTD casts were collected at the actual mooring sites. For some casts, mooring instruments were attached temporarily to the ship CTD system for cross-calibration, and these may have been done anywhere en route to/from the mooring sites. Due to the varying depth ratings of the mooring instruments thus attached, not all CTD casts covered the full water column. The resulting CTD data collection is an irregular pattern of sampling locations and depths, which includes a number of full-depth casts in the vicinity of the moorings.