11.9.2.1 Caribbean

Simulations of the annual Caribbean temperature in the 20th century (1980–1999) by the MMD models give an average that agrees closely with climatology, differing by less than 0.1°C. The inter-quartile range difference between individual models and climatology ranged from –0.3°C to +0.3°C. Thus, the models have good skill in simulating annual temperature. The average of the MMD simulations of precipitation, however, underestimates the observed precipitation by approximately 30%. The deviations in individual models range from –64 to +20%, a much greater range than the deviations in temperature simulations. Recently the Parallel Climate Model (at T42 resolution – about 3.75 degrees), a fully coupled global climate model, was found to be capable of simulating the main climate features over the Caribbean region (Angeles et al., 2007), but it also underestimated the area average precipitation across the Caribbean. Martinez-Castro et al. (2006), in a sensitivity experiment, conclude that the Regional Climate Model (RegCM3), using the Anthes-Kuo cumulus parametrization scheme, can be used for long-term area-averaged climatology.

11.9.2.2 Indian Ocean

For annual temperature in the Indian Ocean in the 20th century (1980–1999), the mean value of the MMD outputs overestimated the climatology by 0.6°C, with 50% of deviations ranging from 0.2°C to 1.0°C. For rainfall, the multi-model ensemble average was only slightly below the mean precipitation by 3%, and the model deviations ranged from –22 to +20%. There are, however, problems with the simulation of year-to-year variation. Many of the important climatic effects of the MJO, including its impacts on rainfall variability in the monsoons, are still poorly simulated by contemporary climate models (see Section 8.4).