Global Sea sea surface salinity anomaly

'''DEFINITION'''

The 2019 anomaly of sea surface salinity is computed at each grid point relative to the 1993-2014 time average. The result is expressed in practical salinity anomaly (no units). A multi-product approach is used, meaning that the anomaly is first computed for 5 different SSS estimates. The average anomaly is then computed, as well as the standard deviation between the five anomalies computations. The evaluation method relies in the study of the consistency in between the 5 different estimates, which provides a qualitative estimate of the robustness of the indicator.

'''CONTEXT'''

Sea surface salinity monitoring is crucial to evaluate changes in the global water cycle, ocean dynamics, and weather and climate (Mulet et al., 2018). In particular, changes in sea surface salinity are closely linked to local imbalances between evaporation and precipitation, to continental runoff and to sea-ice changes (Durack, 2015; Bindoff et al., 2019; Cheng et al., 2020). Resulting net freshwater fluxes are mediated by ocean advection and mixing and clearly feedback into water mass formation and thermohaline circulation changes (Bindoff et al., 2019).