Historical Caribbean Synoptic types and Downscaling to Northeast Puerto Rico Precipitation Variability using Self-Organizing Maps

The tropical forests of Northeast Puerto Rico and the Luquillo Mountains are a large repository for biodiversity and have an important role in regional biogeochemical processes. Precipitation is a key driver of the productivity of these sensitive ecosystems. This study analyzes historical precipitation variability from 1980-2005 along the topographic gradient of the Luquillo Mountains. Self-organizing maps (SOMs) are used to produce synoptic modes of variability from ERA-Interim low-tropospheric moisture and circulation variables over the Caribbean and tropical North Atlantic. These modes of variability are used to downscale to rain gauges in northeast Puerto Rico. Over the study period, changes in daily and monthly precipitation variability are observed. Additionally, output from individual CMIP5 members are validated to determine which models best resolve the synoptic moisture and circulation variability. The synoptic modes of variability during the 2015 extreme drought are analyzed as they may provide insight into future climate change regimes responsible for drought in northeast Puerto Rico.