Simulating the MJO and Convectively Coupled Equatorial Waves
Hung, M.-P., Lin, J.-L., Wang, W., Kim, D., Shinoda, T. and Weaver, S.J. 2013. MJO and convectively coupled equatorial waves simulated by CMIP5 climate models. Journal of Climate 26: 6185-6214.
Although Hung et al. report that their results show that "the CMIP5 models exhibit an overall improvement over the CMIP3 models in the simulation of tropical intra-seasonal variability, especially the MJO and several CCEWs," they concede that (1) "the phase speeds of the model MJO tend to be too slow and the period is longer than observations as part of an over-reddened spectrum, which in turn is associated with too strong persistence of equatorial precipitation," that (2) "the persistence of precipitation in many CMIP5 models is still larger than observations, which is also reflected by the too red precipitation and space-time spectra," and that (3) "only one of the 20 models is able to simulate a realistic eastward propagation of the MJO."