Impacts of Local Convective Processes on Total Water Budgets in the Coastal Tropics via the Analysis of Multi-Sensor Observational Data from the Convection, Aerosol, and Synoptic-Effects in the Tropics (CAST) Experiment

The importance of local convective processes on total water budgets in coastal-tropical Puerto Rico is investigated via the analysis of multi-sensor data from the Convection, Aerosol, and Synoptic-Effects in the Tropics (CAST) campaign. CAST provided an opportunity to quantify the contribution of island-scale effects on rain production during the midsummer drought, dry, and early rainfall seasons (MSD, DS, and ERS respectively). An analysis of 352 rain episodes occurring over Puerto Rico between 1 June 2015 and 12 July 2016 showed that locally induced convective storms accounted for 30.1% of all precipitation events. During the summer months, locally induced storms accounted for 34.6% of all showers, and 30.8% of storms that occurred during the CAST summer phases. While large-scale mechanisms such as the El Niño Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and Saharan dust transport governed moisture conditions over the Caribbean region during the observation period, CAST data shows evidence that local island-scale convective processes involving surface heating, orographic uplift, and sea-breeze trade-wind convergence vary seasonally, and are modifiers that enhanced local convection and rain production over Puerto Rico, thereby impacting the total island-wide water budget.