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ENSO Influence on East Asian-Western Pacific Winter Climate

Paper Reviewed
Gong, H., Wang, L., Chen, W., Nath, D., Huang, G. and Tao, W. 2015. Diverse influences of ENSO on the East Asian-Western Pacific winter climate tied to different ENSO properties in CMIP5 models. Journal of Climate 28: 2187-2202.

Gong et al. (2015) describe their paper's purpose by writing that "the influence of El Niño-Southern Oscillation (ENSO) upon the East Asian-western Pacific (EAWP) climate in boreal winter is investigated via phase 5 of the Coupled Model Intercomparison Project (CMIP5) model results and then compared to that in the phase 3 (CMIP3) results," which they did by utilizing 36 CMIP5 models and 20 CMIP3 models and focusing on "the role played by the differences among models in ENSO properties, including the amplitude and longitudinal extension of ENSO's sea surface temperature (SST) pattern."

In terms of what they learned via this approach, the six Chinese scientists report that (1-2) "an eastward shrinking of ENSO's SST pattern leads to quite weak [i] circulation and [ii] climatic responses over the EAWP regions in the models," that (3-4) "resultant [i] precipitation anomalies and [ii] lower-tropospheric atmospheric Rossby wave responses both extend unrealistically into the Indian Ocean," that (5) "all these features lead to unrealistic climatic impacts of ENSO over the EAWP regions," that (6) "atmospheric responses over the western Pacific are still located farther west than observed," and that (7-8) "unrealistic [i] temperature and [ii] precipitation anomalies are observed over East Asia and Australia," all of which findings, in their words, imply "a common bias of CMIP5 models."

In further commentary on the subject, Gong et al. write that "an unrealistic longitudinal extent of ENSO's SST pattern is a common bias in coupled general circulation models," citing the work of T. Lee et al. (2013). And they go on to additionally draw our attention to "the inability of models to simulate [9] the mean state of SST, [10,11] the climatological trade winds over the [i] tropical and [ii] subtropical Pacific, and [12] the resultant air-sea interactions via Bjerknes feedback," citing the studies of Kim et al. (2014), Magnusson et al. (2013) and Li and Xie (2014), all of which shortcomings suggest that the climate modelling community still has a significant way to go before they will be able to fully rectify the several ENSO-related problems discussed by Gong et al.

Kim, S.T., Cai, W., Jin, F.-F. and Yu, J.-Y. 2014. ENSO stability in coupled climate models and its association with mean state. Climate Dynamics 42: 3313-3321.

Lee, T., Waliser, D.E., Li, J.-L. F., Landerer, F.W. and Gierach, M.M. 2013. Evaluation of CMIP3 and CMIP5 wind stress climatology using satellite measurements and atmospheric reanalysis products. Journal of Climate 26: 5810-5826.

Li, G. and Xie, S.-P. 2014. Tropical biases in CMIP5 multimodel ensemble: The excessive equatorial Pacific cold tongue and double ITCZ problems. Journal of Climate 27: 1765-1780.

Magnusson, L., Alonso-Balmaseda, M. and Molteni, F. 2013. On the dependence of ENSO simulation on the coupled model mean state. Climate Dynamics 41: 1509-1525.

Posted 30 June 2015