Moisture sources for Central America: Identification of moisture sources using a Lagrangian analysis technique

We herein present an analysis of the sources of atmospheric moisture for Central America using a Lagrangian technique. The results of backward and forward moisture tracking analysis using the FLEXPART model has enabled the identification of the main sources of moisture that reach Central America, as well as an evaluation of their spatial evolution during their passage toward the region of interest. Data from the European Center for Medium-Range Weather Forecasts (ECMWF) for a 5 year period (2000-2004) were used as input for the FLEXPART model. The applied method reproduces the variations in the location of the Intertropical Convergence Zone (ITCZ) over the study area very well. The primary source of moisture for Central America is identified over the Caribbean Sea, and a secondary source appears to exist near the equatorial Pacific region. The dominance of the Caribbean Sea region as a source of moisture for this region is clear, as is the importance of the Caribbean Low-Level Jet (CLLJ) as the principal transport mechanism. These characteristics are confirmed by inspection of the moisture transport patterns and their seasonal behavior.