Seasonal sea level variation in the San Andrés, Providencia and Santa Catalina Archipelago, Caribbean Sea

Abstract

The sea level seasonal cycle was assessed in the San Andrés, Providencia and Santa Catalina Archipelago in the Caribbean Sea using 22 years of absolute dynamic topography. Large spatial variability was found in the sea level seasonal spectrum in the 9 most important geographical features that constitute the archipelago, depending on their meridional position and as consequence of different forcings for this cycle present in the Colombian Basin. The sea level annual variation has a minimal range of 2.7 cm in Quitasueño and a maximum range of 9.5 cm in Roncador. The seasonal cycle is maximum in July-August and minimum in January-March toward the north of the archipelago; on the contrary, the seasonal cycle is maximum in February-March and minimum in August-September toward the south of the archipelago. The seasonal cycle explains between the 3 and 23% of the monthly sea level variation in the archipelago and it is not steady in time; changes up to 3.6 cm were found in the amplitude and 83° in the phase lag when the annual cycle was assessed fractionating the time series in 5-year segments. The seasonal cycle contribution must be included in the archipelago’s risk assessment associated to sea level extreme values