Séminaire
In this study, the Regional Climate Model version 4.3 (RegCM4.3) with 18 different parameterization options was forced by the ERA-Interim product under the framework of the Southeast Asia Regional Climate Downscaling(SEACLID)/ Coordinated Regional Climate Downscaling Experiment (CORDEX) - Southeast Asia (or SEACLID/CORDEX-SEA) activities. The model outputs cover a common domain of 15ºS-40ºN, 80ºE-145ºE at 36km resolution.
Fourteen extreme indices for both rainfall and temperature were estimated. To measure the degree of similarity of the 18 experiments in phase and shape, a statistical omega index was used. Results showed relatively higher similarities among the experiments over the mainland Asia compared to those over the Maritime continent for both seasonal and inter-annual variability. The extreme rainfall indices had a lower omega than those of temperature. Observed daily rainfall and temperature data at 52 meteorological stations over the SEA region for the period of 1989-2007 were used to validate the simulated extreme rainfall and temperature indices. Results showed that extreme temperature values were generally underestimated across the region. Systematic biases for each simulated rainfall index were also identified. A score ranking system was established to objectively compare the relative performance of the 18 experiments over the 52 selected stations. It was shown that the experiments with MIT-Emanuel convective scheme performed relatively better than the other ones. The combination of MIT-Emanuel convective scheme with BATS1e ocean flux scheme produced the best performance.
Keywords: CORDEX, Southeast Asia, RegCM, dynamical downscaling, extreme climate index