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This is the second part of a two part series studying simulation characteristics of the Community Climate System Model, version 4 (CCSM4) for various monsoon regimes around the global tropics. Here, the West African, East African, North American, and South American monsoons are documented in CCSM4. Comparisons are made to an Atmospheric Model Intercomparison Project (AMIP) simulation of the atmospheric component in CCSM4 (CAM4), to deduce differences in the monsoon simulations run with observed SSTs and with ocean-atmosphere coupling. These simulations are also compared to a previous version of the coupled model (CCSM3) to evaluate progress. In most, but not all instances, monsoon rainfall is too heavy in the uncoupled AMIP run with the Community Atmosphere Model, version 4 (CAM4), and monsoon rainfall amounts are generally better simulated with ocean coupling in CCSM4. Some aspects of the monsoon simulations are improved in CCSM4 compared to CCSM3. Early-season rainfall in the West African monsoon is better simulated in CAM4 than in CCSM4 presumably because of the specification of SSTs in the Gulf of Guinea, but the Sahel rainfall season is captured better in CCSM4 as are the African easterly jet and the tropical easterly jet. Improvements in the simulation of the Sahel rainy season (July, August, and September) in CCSM4 compared with CCSM3 are significant, but problems remain in the simulation of the early season (May and June) in association with the misrepresentation of eastern Atlantic (Gulf of Guinea) SSTs. Precipitation distributions and the southwesterly low-level inflow in the North American monsoon are improved in CCSM4 compared to CCSM3. Both CAM4 and CCSM4 reproduce the seasonal evolution of rainfall over the South American monsoon region, but the location of maximum rainfall is misplaced to the northeast in both models. [ABSTRACT FROM AUTHOR]

Simulations of regional monsoon regimes, including the Indian, Australian, West African, South American, and North American monsoons, are described for the T85 version of the Community Climate System Model version 3 (CCSM3) and compared to observations and Atmospheric Model Intercomparison Project (AMIP)-type SST-forced simulations with the Community Atmospheric Model version 3 (CAM3) at T42 and T85. There are notable improvements in the regional aspects of the precipitation simulations in going to the higher-resolution T85 compared to T42 where topography is important (e.g., Ethiopian Highlands, South American Andes, and Tibetan Plateau). For the T85 coupled version of CCSM3, systematic SST errors are associated with regional precipitation errors in the monsoon regimes of South America and West Africa, though some aspects of the monsoon simulations, particularly in Asia, improve in the coupled model compared to the SST-forced simulations. There is very little realistic intraseasonal monsoon variability in the CCSM3 consistent with earlier versions of the model. Teleconnections to the tropical Pacific are well simulated for the South Asian monsoon. [ABSTRACT FROM AUTHOR]