Polade: Natural climate variability and teleconnections to precipitation over the Pacific-North American region in CMIP3 and CMIP5 models
Figure 2. Pattern correlation of the leading SVD mode of modeled and observed SST versus pattern correlation of the leading SVD mode of modeled and observed precipitation (panel a). Blue and red symbols represent CMIP3 and CMIP5 models, respectively. Grey contour lines indicate model skill (higher values mean greater skill; see text for details). The skill difference between CMIP5 and CMIP3 models (panel b; see text for details).
Natural climate variability and teleconnections to precipitation over the Pacific-North American region in CMIP3 and CMIP5 modelsbr>
Natural climate variability will continue to be an important aspect of future regional climate even in the midst of long-term secular changes. Consequently, the ability of climate models to simulate major natural modes of variability and their teleconnections provides important context for the interpretation and use of climate-change projections. Comparisons reported here indicate that the CMIP5 generation of global climate models shows significant improvements in simulations of key Pacific climate mode and their teleconnections to North America compared to earlier CMIP3 simulations. The performance of fourteen models with simulations in both the CMIP3 and CMIP5 archives are assessed using singular value decomposition analysis of simulated and observed winter Pacific sea-surface temperatures (SSTs) and concurrent precipitation over the contiguous United States and northwestern Mexico. Most of the models reproduce basic features of the key natural mode and their teleconnections, albeit with notable regional deviations from observations in both SST and precipitation. Increasing horizontal resolution in the CMIP5 simulations is an important, but not a necessary factor in the improvement from CMIP3 to CMIP5.
Suraj D. Polade1,*, Alexander Gershunov1, Daniel R. Cayan1,2, Michael D. Dettinger2, David W. Pierce1
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