How well do the current state-of-the-art CMIP5 models characterise the climatology of the East Asian winter monsoon?

Abstract

Previous studies have revealed some common biases in coupled general circulation model's simulations of the East Asian (EA) winter monsoon (EAWM), including colder surface air temperature and more winter precipitation over the EA region. In this study, we examined 41 fully coupled atmosphere-ocean models from fifth phase of the Coupled Model Intercomparison Project (CMIP5), which will be widely used in the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC), and address whether the current state-of-the-art CMIP5 models can characterise the climatology of the East Asian winter monsoon. We also compared the results with the models from third phase of CMIP, which was extensively used in the fourth assessment report of the IPCC. The results show that the cold surface air temperature (SAT) bias is lessened and the precipitation amount decreased with the current CMIP5 models. Moreover, the CMIP5 models performbetter at predicting surface winds and high-level jet streams than the CMIP3 models. Moreover, CMIP5 models show more model consistency in most EAWM parameters, and the interannual variability of the SAT is closer to the observations. We also examined the change in the radiation energy budget in the CMIP5 models and compared with CMIP3 models. Although the improvements are significant, deficiencies still exist in the simulation of the EAWM, e.g., the stronger EA major trough and the stronger zonal sea level pressure gradient.

Activity Characteristics of the East Asian Trough in CMIP5 Models

“…The decadal weakening of EAT is also captured by most of the coupled climate models in IPCC AR4 [19]. Under a global warming scenario, the EAT becomes shallower and shifts northeastward in the coupled climate models [20][21][22][23]. The performances of the models in the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating EAWM are better than those in CMIP3 [23].…”

“…The performances of the models in the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating EAWM are better than those in CMIP3 [23]. The multimodel ensemble (MME) of CMIP5 models is able to reproduce the overall characteristics of EAWM very well [24,25], although the climatological strength of the EAT is overestimated by most of the models [23,24]. However, the performances of CMIP5 models in the variation of EAT are unclear.…”

“…Under a global warming scenario, the EAT becomes shallower and shifts northeastward in the coupled climate models [20][21][22][23]. The performances of the models in the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating EAWM are better than those in CMIP3 [23]. The multimodel ensemble (MME) of CMIP5 models is able to reproduce the overall characteristics of EAWM very well [24,25], although the climatological strength of the EAT is overestimated by most of the models [23,24].…”

The Influences of the Model Configuration on the Simulation of Stratospheric Northern-Hemisphere Polar Vortex in the CMIP5 Models

“…In recent decades, great progress has been made in the current climate models to have higher resolutions (both horizontal and vertical), more complete physical processes, and more sophisticated parameterization schemes. This has greatly improved model performance and applicability for climate change projections on global to regional scales [1][2][3].…”

The effect of a well-resolved stratosphere on East Asian winter climate

“…There have been several evaluation studies with focus on the model reproduction of East Asian summer and winter monsoon climate (e.g., Boo et al 2011;Gong et al 2014;Wei and Bao 2012;Wei et al 2014). It was shown that in the winter season, the current state-of-the-art CMIP5 models have the ability to reproduce circulation in EA region and progress had been made to relieve the surface cold bias, which was observed in the CMIP3 model ensemble.…”