Sea-level trends and interannual variability in the Caribbean Sea

Sea-level trends and their forcing have been investigated in the Caribbean Sea using altimetry and tide gauge time series from 19 stations. The basin average sea-level rise is 1.7 ± 1.3 mm yr^-1 for the period 1993-2010. Significant spatial variability of the trends is found. The steric variability above 800 m combined with the global isostatic adjustment explains the observed trends for the altimetry period in most of the basin. Wind forcing changes causes the trends in the southern part of the basin, modulating the sea level through changes in the ocean circulation. The longest time series (102 years) of Cristobal shows a trend of 1.9 ± 0.1 mm yr^-1 insignificantly different from the global mean sea-level rise for the twentieth century. By contrast Cartagena, a world heritage site, has a large trend (5.3 ± 0.3 mm yr^-1) significantly affected by local vertical land movements. Stations dominated by the steric contribution have smaller trends (∼1.3 ± 0.2 mm yr^-1). Sea-level trends at tide gauges are not affected by atmospheric pressure changes or by the open ocean steric contribution at most stations. Decadal variability in the sea-level trends can partly be explained by steric and wind variability. The decadal variability in the trends is not spatially coherent. Interannual sea-level variability accounts for one third of the total sea-level variability and can be partly explained by the influence of El Niño-Southern Oscillation at different time and spatial scales. No correlation with the North Atlantic Oscillation is found.