Atmospheric teleconnections and their effects on the annual and seasonal rainfall climatology of Puerto Rico

This study examines the relationship between rainfall and the North Atlantic Oscillation (NAO), Arctic Oscillation (AO), El Nino Southern Oscillation (ENSO), and the Atlantic Multi-decadal Oscillation (AMO) in the island of Puerto Rico. Monthly rainfall data for 30 weather stations during the time period of 1960-2012 in Puerto Rico were used in this study. Pearson's correlation tests and forward stepwise regression models were used to examine the relationship between annual, dry season (Dec-April), and wet season (May-Nov) rainfall and each of the teleconnection indexes. A factor analysis regionalization (FAR) was employed in order to group and reduce the number of stations to only a few regions. The annual, dry season, and wet season rainfall regions were regressed with their respective NAO, AO, ENSO, and AMO indexes. The AO and NAO exhibited significant negative correlations with annual rainfall for stations located in the northwestern and central mountain regions of the island; however, no stations showed a significant relationship with ENSO. The AMO exhibited significant positive correlations with annual, dry, and wet season rainfall over Puerto Rico for stations in different regions of the island. The AMO was found to have the strongest control on annual and seasonal rainfall in Puerto Rico.