Meteorological Society of Japan, Journal of the Meteorological Society of Japan, 4(87), p. 771-789, 2009
DOI: 10.2151/jmsj.87.771
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Precipitation and high-level cloud (HLC) areas in association with the large-scale circulation over the tropical Pacific are analyzed for simulations of nineteen Coupled Model Intercomparison Project Phase 3 (CMIP3) models with observations for 16 years of 1984–1999. The distribution of rainfall and HLC areas are composited around the geographical center of tropospheric upper-level (200 hPa) divergence (DIV) along Intertropical Convergence Zone (ITCZ) using monthly anomaly data. Datasets with a finer temporal sampling than monthly means were not available for the present purposes. The most notable feature is that the horizontal spread of enhanced circu-lation and the related rainfall and HLC areas are all underestimated around the DIV center in the models com-pared to the observation. Particularly, the underestimation is pronounced in HLC, presumably owing to di‰cul-ties in the physical processes relevant to the spatial distribution of HLC area. In general, a model with a higher correlation between the large-scale circulation field and rainfall tends to have a wider spread of HLC area around the DIV center.