Abstract

The temporal variability and spatial pattern of the Arctic Oscillation (AO) simulated in the historical experiment of 26 coupled climate models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) are evaluated. Spectral analysis of the monthly AO index indicates that 23 out of the 26 CMIP5 models exhibit no statistically significant spectral peak in the historical experiment, as seen in the observations. These models are able to reproduce the AO pattern in the sea level pressure anomaly field during boreal winter, but the intensity of the AO pattern tends to be overestimated in all the models. The zonal-mean zonal wind anomalies associated with the AO is dominated by a meridional dipole in the mid-high latitudes of the Northern Hemisphere during boreal winter, which is well reproduced by only a few models. Most models show significant biases in both strength and location of the dipole compared to the observation. In considering the temporal variability as well as spatial structures in both horizontal and vertical directions, the MPI-ESM-P model reproduces an AO pattern that resembles the observation the best. Zuo, J.-Q., W.-J. Li, and H.-L. Ren, 2013: Representation of the Arctic Oscillation in the CMIP5 models. Adv . Clim . Change Res ., 4 (4), doi: 10.3724/SP.J.1248.2013.242.

Abstract

The climate system models from Beijing Climate Center, BCC_CSM1.1 and BCC_CSM1.1-M, are used to carry out most of the CMIP5 experiments. This study gives a general introduction of these two models, and provides main information on the experiments including the experiment purpose, design, and the external forcings. The transient climate responses to the CO2 concentration increase at 1% per year are presented in the simulation of the two models. The BCC_CSM1.1-M result is closer to the CMIP5 multiple models ensemble. The two models perform well in simulating the historical evolution of the surface air temperature, globally and averaged for China. Both models overestimate the global warming and underestimate the warming over China in the 20th century. With higher horizontal resolution, the BCC_CSM1.1-M has a better capability in reproducing the annual evolution of surface air temperature over China. Xin, X.-G., T.-W. Wu, and J. Zhang, 2013: Introduction of CMIP5 experiments carried out with the climate system models of Beijing Climate Center. Adv. Clim. Change Res., 4 (1), doi: 10.3724/SP.J.1248.2013.041.

Abstract

Historical simulations of annual mean surface air temperature over China with 25 CMIP5 models were assessed. The observational data from CRUT3v and CN05 were used and further compared with historical simulations of CMIP3. The results show that CMIP5 models were able to simulate the observed warming over China from 1906 to 2005 (0.84°C per 100 years) with a warming rate of 0.77°C per 100 years based on the multi-model ensemble (MME). The simulations of surface air temperature in the late 20th century were much better than those in the early 20th century, when only two models could reproduce the extreme warming in the 1940s. The simulations for the spatial distribution of the 20-year-mean (1986–2005) surface air temperature over China fit relatively well with the observations. However, underestimations in surface air temperature climatology were still found almost all over China, and the largest cold bias and simulation uncertainty were found in western China. On sub-regional scale, northern China experienced stronger warming than southern China during 1961–1999, for which the CMIP5 MME provided better simulations. With CMIP5 the difference of warming trends in northern and southern China was underestimated. In general, the CMIP5 simulations are obviously improved in comparison with the CMIP3 simulations in terms of the variation in regional mean surface air temperature, the spatial distribution of surface air temperature climatology and the linear trends in surface air temperature all over China. Guo, Y., W.-J. Dong, F.-M. Ren, et al., 2013: Surface air temperature simulations over China with CMIP5 and CMIP3. Adv. Clim. Change Res., 4 (3), doi: 10.3724/SP.J.1248.2013.145.

Abstract

Evaluation and projection of temperature extremes over China are carried out with 8 model datasets from CMIP5. Compared with the NCEP reanalysis data, multi-model weighted ensemble is capable of reproducing the 8 temperature extreme indices and 20-year return values of annual maximum/minimum temperatures. The time correlation coefficients of all the 8 indices between multi-model ensemble and the reanalysis can reach a significance level of 0.10. The spatial correlation coefficient of 20-year return level of annual maximum/minimum temperatures is greater than 0.98. Under the RCP4.5 scenario, more extreme warm events and less cold events are expected over China in multi-model ensemble. By the middle of the 21st century, the heat wave duration index will be multiplied 2.6 times. At the end of the 21st century, the cold wave duration index will decrease 71%, and the 20-year return value will increase 4°C in parts of China for the maximum/minimum temperatures. Yao, Y., Y. Luo, J.-B. Huang, 2012: Evaluation and projection of temperature extremes over China based on CMIP5 model. Adv. Clim. Change Res., 3 (4), doi: 10.3724/SP.J.1248.2012.00179.