POSITION - GEOGRAPHIC collected from CARTHE surface drifter in South Atlantic Ocean from 20230306 to 20230727 (NCEI Accession 0301712)

We deployed 200 CARTHE surface drifters drogued at 0.60 m depth. The sampling rate was set to every 10 minutes, giving theoretical battery life expectancy of more than 3 months. The GPS signal was very good despite constant difficult weather (winds and waves).

The deployments followed a radiator pattern consisting of 4 12km-long lines aligned with the wind and separated by 3.5 km. We dropped 4 nodes of 3 drifters per line, separated by 0.5km, 1 km, and 2 km. This set up was chosen to provide synoptic and isotropic sampling of the submesoscale range and minimize the deployment time from a single ship. It took 3 to 4 hours at full speed (8 to 12 knots) to complete a deployment depending on conditions. The location for each deployment was determined based on analysis of the most recent SSH and SST fields available, as well as shipboard ADCP plots, TSG transects, and weather forecasts (ECMWF).