Influence of the Atlantic Warm Pool on the Cimate of the Lesser Antilles

Contact Person: Misra, Vasubandhu
Collaborators: Misra, V.
Institutions: Florida State University
Funding Agency: USGS
Status: Funded
Abstract: The sustainability of a society and in this context of island nations is critically dependent on the fresh water availability. A significant source of the fresh water in these islands comes from precipitation. In this research we propose to study the rainfall variability of the Lesser Antilles in the late boreal summer-early fall (August-September-October [ASO]) season. Since most of the current global climate models are so coarse in horizontal resolution that these islands of the Lesser Antilles are not even resolved. As a result the interpretation of the predictions of say interannual variations of rainfall, surface temperature over these islands are based on the large-scale variations. There is however reason to speculate that there could be some local feedback mechanism such as that of the land-atmosphere interactions, or the influence of local orography that may influence the local climate, unresolved in the global climate models. This mechanistic study offers to first understand the role of the interannual variations of the surrounding oceans on the rainfall variations of the Lesser Antilles. This could lead to a possible insight to the behavior of the ASO rainfall in the Lesser Antilles in a warming climate. This study is investigating a possible source of predictability of the ASO seasonal rainfall variation from the slowly varying Atlantic Warm Pool (AWP) area. Furthermore, this study will also help us in understanding the influence on the Lesser Antilles ASO seasonal rainfall by the large-scale variations of the Sea-Surface Temperature (SST) in the tropical Atlantic Ocean at longer temporal scales of decadal variability and climate change signal. The research focus on the season of ASO assumes significance as it coincides with the annual peak of the Atlantic hurricane season. Therefore, as a consequence we will also be examining the impact of the interannual variations of the frequency and intensity of the extreme rain events from tropical storms on the local terrestrial hydrological budget. All of these research objectives are of great relevance to regional water managers, farmers, policy makers and to the tourism industry as all of these constituents are critically dependent on fresh water sources in these islands.