Hydroclimate changes over Central America and the Caribbean in a global warming climate projected with 20-km and 60-km mesh MRI atmospheric general circulation models

Abstract

   Future hydroclimate projections for Central America and the Caribbean were investigated with quantified uncertainties using 20-km and 60-km mesh global atmospheric general circulation models. In these regions, only a few future climate projections with high horizontal resolutions are available, although Central America and the Caribbean are characterized by spatial and temporal complexities in climate. Horizontal resolutions of 20 km and 60 km are comparable to those of regional climate models for a large region. Both the 20-km and 60-km mesh models reproduced reasonably well the observed seasonal precipitation patterns. Precipitation was projected to decrease in most of this region in all seasons by the end of this century. Evaporation from the ocean was projected to increase throughout the year, except in the Intertropical Convergence Zone, whereas evaporation from land areas was generally projected to decrease in the dry season and to increase in the rainy season. Surface soil moisture and total runoff in most land areas were therefore projected to decrease in both models in all seasons. Annual mean streamflow in the future climate was projected to decrease in most of Central America and the Caribbean as a result of decreased precipitation and increased evaporation. The values of hydroclimate variables over four land-only domains in the future climate changed significantly on a monthly basis within each season. In contrast, changes in the annual means of hydroclimate variables for individual countries were highly uncertain.