ENSO Behavior in Evolving Climate Models: CMIP5 vs. CMIP3
Zhang, W. and Jin, F.-F. 2012 Improvements in the CMIP5 simulations of ENSO-SSTA Meridional width. Geophysical Research Letters 39: 10.1029/2012GL053588.
Seeking the anticipated fruits of progress, Zhang and Jin ask the obvious question: "Does the systematical narrow bias in ENSO width still exist in current models developed for Phase 5 of the CMIP (CMIP5)?" And they then go on to answer their own question by assessing the ENSO meridional widths simulated by 15 CMIP5 models and 15 CMIP3 models for the period 1900-1999, comparing the results of both groups against observation-based monthly SST data from the Hadley Center Sea Ice and Sea Surface Temperature (HadISST) data of Rayner et al. (2003).
In doing so the two researchers report that "a systematic narrow bias in ENSO meridional width remains in the CMIP5 models," although they state that the newest results represent "a modest improvement over previous models." One question, however, yet remains to be answered with respect to this particular aspect of model performance: Is a modest improvement good enough? ... especially when considering the time, money and scientific effort put into the program that produced it, and knowing, in the words of Zhang and Jin, that "models with a better performance in ENSO width tend to simulate the precipitation response to ENSO over the off-equatorial eastern Pacific more realistically."
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