Sensitivity of precipitation and atmospheric low-level circulation patterns to domain size and choice of parameterization schemes in RegCM4.4 over Central America

The sensitivity of regional climate model simulations to domain size and position is becoming increasingly important for generating reliable scenarios. In this study, the Central America CORDEX (CCA) at 50 km horizontal resolution with a relaxation zone 10° around boundaries (CCA+) was taken as basis increase in RegCM4.4 model. low-level circulation precipitation patterns over America, western Caribbean Sea, eastern tropical Pacific do not show strong changes an area increment 18, 32, 52% respect CCA+. physical configuration has greater impact on representation relevant characteristics atmospheric processes. Simulated 925 hPa winds jet (CLLJ) region unrealistic winter summer intensities, especially July. Similar issues were found other studies CCA domain, using different models configurations. A reduction critical Richardson number selected planetary boundary layer scheme resulted little change strength component CLLJ. completely capture key such mid-summer drought, due limitations adequately representing circulation. However, Grell cumulus parameterization perform relatively better than those mixed (Grell land-Emanuel ocean).