Mechanism study of the 2010–2016 rapid rise of the Caribbean Sea Level

Abstract

The Caribbean Sea level increased rapidly by about 6.55 cm in the period 2010–2016. This dramatic rise occurred concurrently with a step change in basin mass (freshwater equivalent) of about 1.09 cm (relative to 2006–2009) and an increase in surface freshwater loss of about 5.96 cm. Using re-analysis and satellite-derived atmosphere and ocean physics datasets, we investigate the driver for this episode of sea level rise and its impact on vertical water structure. Our conclusion is that increase in Caribbean sea evaporation, which removes latent heat and cools surface waters, caused upward longwave radiation to decrease, resulting in warming and total steric sea level rise of about 5.34 cm; and saline water that compensated for increased surface freshwater loss caused basin mass to increase due to the additional salt. Because of these concurrent changes, surface layer and mixed layer salinity and temperature increased; and adjustments of the Atlantic inflow and Gulf of Mexico return flow (equivalent net lateral exchange increase of about 7.05 cm) deepened the interface between the stratified top water and bottom rest water of the Caribbean Sea. This study highlights the useful role of the Caribbean Sea for illustrating local mechanisms and patterns of sea level variability in a changing global climate.