The Contribution of the Vendée Globe Race to Improved Ocean Surface Information: A Validation of the Remotely Sensed Salinity in the Sub-Antarctic Zone

• Published in: Journal of Marine Science and Engineering
• Main Authors: Marta Umbert, Nina Hoareau, Jordi Salat, Joaquín Salvador, Sébastien Guimbard, Estrella Olmedo, Carolina Gabarró
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2022
• Subjects: sea surface temperature; sea surface salinity; ocean circumnavigation; ships of opportunity; SMOS validation; sub-Antarctic zone; Antarctic; Patagonia; Pacific; Indian; Antarc*; Antarctica
• Online Access: https://doi.org/10.3390/jmse10081078

The Vendée Globe is the world’s most famous solo, non-stop, unassisted sailing race. The Institute of Marine Sciences and the Barcelona Ocean Sailing Foundation installed a MicroCAT on the One Ocean One Planet boat. The skipper, Dídac Costa, completed the round trip in 97 days, from 8 November 2020 to 13 February 2021, providing one measurement of temperature and conductivity every 30 s during navigation. More than half of the ship’s route was in the sub-Antarctic zone, between the tropical and polar fronts, and it passed through areas of oceanographic interest such as Southern Patagonia (affected by glacier melting), the Brazil–Malvinas confluence, the Southern Pacific Ocean, and the entire Southern Indian Ocean. This sailing race gave a rare opportunity to measure in-situ sea surface salinity in a region where satellite salinity measurements are not reliable. Due to the decreased sensitivity of brightness temperature to salinity in cold seas, retrieving sea surface salinity at high latitudes remains a major challenge. This paper describes how the data are processed and uses the data to validate satellite salinity products in the sub-Antarctic zone. The sailing race measurements represent surface information (60 cm depth) not available from drifters or Argo floats. Acquiring measurements using round-the-world sailing races would allow us to analyse the evolution of ocean salinity and the impact of changes in the ice extent around Antarctica.