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CMIP5 Modelling of Precipitation in Arid and Semiarid Regions

Paper Reviewed
Zhao, T., Chen, L. and Ma, Z. 2014. Simulation of historical and projected climate change in arid and semiarid areas by CMIP5 models. Chinese Science Bulletin 59: 412-429.

Using CRU TS3.1 monthly temperature and GPCC V6 monthly precipitation datasets, Zhao et al. (2014) conducted a systematic assessment of 17 CMIP5 climate models, focusing on long-term trends of precipitation in arid and semi-arid areas.

This work revealed, as they describe it, that (1,2) "simulated precipitation is only about one-third the intensity of that seen in observations, and one-fifth the long-term trend of observations," that (3) "there are huge spreads among the models in their reproduction of precipitation long-term changes," that (4) "long-term climate trends in the simulated results get weaker than those in the observations," that (5) "over certain areas, precipitation simulations have even gotten worse from CMIP3 to CMIP5," that (6,7) "the increasing of precipitation over central Africa and the south-drier/north-wetter dipole precipitation structure over East China are not in agreement with observations," and that (8,9) "the poor simulation of precipitation is possibly due to model limitations in representing cloud changes [plus] the associated feedback over tropical and sub-tropical areas," as has previously been described by Lauer and Kevin (2013).

In concluding their paper, and in light of this significant list of still-unsolved problems, the three Chinese researchers state that, in general, "model simulations of precipitation seem to still have a long way to go," while noting more specifically that "the application of CMIP5 multi-model simulations requires further dynamical downscaling adjustment at regional scales."

Lauer, A. and Kevin, H.K. 2013. Simulating clouds with global climate models: a comparison of CMIP5 results with CMIP3 and satellite data. Journal of Climate 26: 3823-3845.

Posted 24 March 2015