Revista de Biología Tropical Vol.60 (suppl. 2)
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Ítem Atmospheric forcing of cool subsurface water events in Bahía Culebra, Gulf of Papagayo, Costa Rica(Revista Biología Tropical, 60 (2): 173-186, 2012-04) Alfaro Martínez, Eric J.; Cortés Núñez, JorgeBahía Culebra, at Gulf of Papagayo on the north Pacific coast of Costa Rica, is an area of seasonal upwelling where more intense cooling events may occur during some boreal winter weeks mainly. To study these extreme cool events, records of nine sea subsurface temperature stations from 1998 to 2010 were analyzed. Five events associated with extremely cool temperatures in this region were identified from these records and taken as study cases. Sea temperatures decreased about 8-9ºC during these events and occurred while cold fronts were present in the Caribbean, with strong trade wind conditions over Central America. These strong wind conditions may have favored the offshore displacement of the sea surface water. The axis of Bahía Culebra runs northeastsouthwest, a condition that favors and triggers cool water events, mainly because the displaced water is replaced by water from deeper levels. Rev. Biol. Trop. 60 (Suppl. 2): 173-186. Epub 2012 April 01.Ítem Un método para evaluar el enriquecimiento de metales en sedimentos marinos en Costa Rica(Revista Biología Tropical 60 (2): 197-211, 2012-04-01) Lizano Rodríguez, Omar Gerardo; Alfaro Martínez, Eric J.; Salazar Matarrita, AlfonsoA method to evaluate metal enrichment in marine sediments. In order to evaluate metal enrichment in sediments , a method is proposed and tested in Bahia Culebra and the Golfo de Nicoya, Costa Rica through the normalization of the elements against aluminum, and by linear regression of the logarithm of the concentrations of different elements respect to aluminum. The distributions of the elements manganese, and strontium of Bahía Culebra did not satisfy the tests of normalization and linear regression, indicating a nonnatural distribution or enrichment of these elements in this region. In the Golfo de Nicoya the elements copper , zinc , rubidium and the strontium did not satisfy the test of normality or the linear regression with respect to aluminum, indicating a possible enrichment of these elements. The majority of the concentrations of the elements in two sample sites, with the exception of chromium, are within the natural ranges in rocks or clays of marine sediments, and within the concentration ranges of other studies done in these same regions. Chromium has average values beyond the natural concentrations, the values of some samples in the Golfo de Nicoya are up to 10 times greater than the concentration value of a typical bay with high contamination of this element.Ítem Clima y temperatura sub-superficial del mar en Bahía Culebra, Golfo de Papagayo, Costa Rica(Revista Biología Tropical, 60 (2): 159-171, 2012-04) Alfaro Martínez, Eric J.; Alvarado Barrientos, Juan José; Jiménez Centeno, Carlos; León, Alberto; Sánchez Noguera, Celeste; Nivia Ruiz, Jaime; Cortés Núñez, Jorge; Ruiz Campos, EleazarBahía Culebra, Golfo de Papagayo, Costa Rica is a seasonal upwelling area. To determine the relationship of climate and the subsurface temperature variability at Bahía Culebra, we analyzed nine records of sea subsurface temperature from the Bay, continuously recorded from 1998 to 2010. The analysis characterized the annual cycle and explored the influence of different climate variability sources on the subsurface sea temperature and air temperature recorded in Bahía Culebra. Data from an automatic meteorological station in the bay were studied, obtaining the annual and daily cycle for air surface temperature and wind speed. Sea surface temperature (SST) trend from 1854 to 2011 was calculated from reanalysis for the region that coverts 9-11°N, 85-87°W. Because of the positive SST trend identified in this region, results showed that annual and daily cycles in Bahía Culebra should be studied under a warming scenario since 1854, that is coherent with the global warming results and its climate variability is influenced by El Niño-Southern Oscillation (ENSO) in the Equatorial Pacific and by atmospheric forcing triggered by climate variability with Atlantic Ocean origin, because warm (cold) events in Bahía Culebra tend to occur in concordance with positive & negative (negative & positive) anomalies in Niño 3.4 (NAO) index. Rev. Biol. Trop. 60 (Suppl. 2): 159-171. Epub 2012 April 01.