Co-variability of sea surface salinity and sea surface temperature in the North Atlantic ocean during 2022 and 2023.

Sea Surface Salinity (SSS) plays an important role in the global water cycle, which appears to be intensifying due to climate change. SSS also influences the vertical distribution of heat in the ocean because of its influence on water density.

 

The variability of SSS before, during and after extreme SST events will be assessed in the North Atlantic Ocean, with a particular attention to the changes in atmospheric conditions during these events. Both positive and negative SSS anomalies are observed during extreme SST events, which may indicate that different oceanic and atmospheric processes are at play during each event. The analysis will be done for the years 2022 and 2023. The lattest showed an unprecedented SST anomaly in large parts of the North Atlantic region, which has been object of numerous studies. The role played by SSS during the unfolding of these extreme temperatures in the North Atlantic Ocean has not yet been carefully studied. We’ll also focus in different subregions of the North Atlantic Ocean, in order to assess the occurrence of different SST/SSS regimes.

 

The length of the satellite SSS time series (14 years) does not allow for a proper calculation of a baseline climatology, and therefore a mixed approach needs to be taken. To this end, different model-based and data-based reanalyses and products will be compared, with the objective of building a common climatology. Large differences are observed between satellite SSS estimates and reanalyses, especially in coastal regions and enclosed seas, which make this a challenging task.