PESSACG Natalia Liz
congresos y reuniones científicas
The radiation budget in RCMs over South America
N. L. PESSACG; S. A. SOLMAN; P. SAMUELSSON; E. SANCHEZ
Workshop; Meeting CLARIS-LPB M36; 2011
The long- and short-wave components of the earths radiation budget are important terms in climate modelling, describing the sources and sinks of energy in the earth- atmosphere system. These terms govern the energy balance of the earth and control daily and annual cycles. Thus, it is necessary to evaluate the radiation budget of regional climate models and to identify sources of uncertainties (Khote et al, 2010). In this context, a preliminary analysis of the capability of the ERAinterim simulations to represent the energy budgets is presented. Five RCMs from the ERA-Interim simulations available from WP5/CLARIS-LPB were used for the long-wave radiation budget (MM5, PROMES, RCA, REMO and RegCM3) and six for the short-wave radiation budget (MM5, PROMES, RCA, REMO, RegCM3 and ETA). Simulations results were compared with data provided by the GEWEX SRB Project.GEWEX SRB Project provides satellite-based data set of monthly means short and long wave components at surface on a 1°global grid (Gupta et al. 2006). The period of analysis was 1990-2007 in which is available the GEWEX SRB dataset. The results showed that in general the RCMs underestimate the net short wave radiation budget at surface and magnitude of the long wave radiation budget at surface. The main sources of errors in the simulated radiation budget components are due to the cloud fraction, albedo and surface temperature errors. In this preliminary work it is clear that the strong underestimation (overestimation) of net short-wave radiation budget at surface is connected mainly to the strong overestimation (underestimation) of albedo. Besides that, there is a clear relationship in specific regions of South America, over the Peruvian coast as example, where the errors in short and long-wave radiation budgets are related with errors in the cloud fraction simulation.