Condiciones hidrográficas y climatológicas en el Caribe Sur de Costa Rica durante El Niño 2014-2016

In May, June, September and October 2014 and June, August, September and November 2015, hydrographic campaigns were carried out in the Southern Caribbean of Costa Rica in order to determine the influence of the El Nino phenomenon on this region. With a conductivity, temperature and depth profiler, temperature, salinity and chlorophyll a were determined in 23 stations. The surface temperature was between 26.6-30°C, surface salinities between 29-33.5 UPS, and surface chlorophyll a varied between 1.1 mg m-3-0.1 mg m-3. There is a thin mixture layer (T ~ 29°C), which did not exceed 20 m depth in 2014 and extended to 40 m in September and November 2015. The thermohaline indexes of the Caribbean Surface Water presented a significant decrease in its salinity by dilution due to El Nino and a slight increase in its temperature. The analysis between a temporal series of sea surface temperature at a point 15 km off Cahuita and the Oceanic Nino Index (ONI), determined that the area under study has a warm-up signal with a lag of 7 months following the presence of El Nino in the Tropical Pacific Ocean. During the 2014-2016 El Nino the studied area presented in some months precipitation that exceeded the climatological value by more than 50%.