Abstract

Climate Models are the main tools available for developing projections of climate change in the future. Due to the inter-model differences in internal physics and the process of parameterization of the variables, it is essential to consider the range of projections from different models rather than depending on projection of one climate model only. In this study, multi-model ensemble for future projections of hydro-climatic parameters in terms of precipitation and temperature is developed on monthly resolution for each of the year from 2011 to 2100 with respect to a baseline period of 1971-2000 for Bangladesh. Simulations of four Global Climate Models (GCMs) named CGCM3.1, CCSM3, MIROC3.2 and HadGEM1 are applied for this purpose. An ensemble technique comprising Root Mean Square Error (RMSE) and Weight Factor has been thoroughly discussed. In line with this method, larger weight or preference is given to the GCM that has less error with respect to the observed temperature and precipitation values in the baseline. Prominent large scatters have been observed in the time-series plots for monthly multi-model ensemble precipitation, which resemble highly intensive and more inconsistent temporal precipitation pattern in future. In addition, mean surface temperature is likely to increase invariably in every month.

Keywords: Bangladesh; Climate change; Ensemble; GCM; Multimodel; Precipitation; Temperature