Dynamical characteristics of drought in the Caribbean from observations and simulations

Abstract

Climate models consistently project a significant drying in the Caribbean during climate change, and between 2013–2016 the region experienced the worst multi-year drought in the historical period. Although dynamical mechanisms have been proposed to explain drought in the Caribbean, it is unknown the contributions from mass convergence and advection to precipitation-evaporation (P-E) anomalies during drought. Here we analyze the dynamics of contemporaneous droughts in the Caribbean by decomposing the contributions of mass convergence and advection to P-E using observational and simulated data. We find that droughts arise from an anomalous subsidence over the southeastern Caribbean and northeastern South America. Although the contributions from mass convergence and advection vary across the region, it is mass convergence that is the main driver of drought in our study area. A similar dynamical pattern is observed in simulated droughts using the Community Earth System Model (CESM) Large Ensemble (LENS).