Models - Climate System Model

BCC_CSM1.1 is the version 1.1 of the Beijing Climate Center Climate System Model (BCC_CSM1.1) developed at the Beijing Climate Center (BCC), China Meteorological Administration (CMA), based on NCAR CCSM2.0.1. It is a fully coupled global climate–carbon model including interactive vegetation and global carbon cycle, in which the atmospheric component BCC_AGCM2.1, ocean component MOM4-L40, land component BCC_AVIM1.0, and sea ice component SIS are fully coupled and interact with each other through fluxes of momentum, energy, water and carbon at their interfaces. Information between the atmosphere and the ocean is exchanged once per simulated day. The exchange of atmospheric carbon with the land biosphere is calculated at each model time step (20 min). Further details can be referred to Wu et al. (2012a; 2012b).

BCC_CSM1.1 has participated in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and conducted most of the CMIP5 experiments (Xin et al., 2012a). Model outputs are available in PCMDI gateway and also on our local servers. Here are some studies based on the CMIP 5 simulations.

(1) The historical experiment (historical): Global and China mean SAT are closely correlated with the observation with coefficient at 0.9 and 0.57, respectively. By the year 2005, the model simulate a warming amplitude about 1oC than the climatology (1961-1990 mean) in consistent with the observation. Distributions of warming trend over China during 1958-2004 are reasonably reproduced with the largest trend occurred in winter. Although the spring cooling over Southwestern China is partially reproduced, the cooling trend over middle-East China in summer is missing. For the precipitation changes, BCC_CSM1.1 has best performance in capturing the spring drought in Southeast China. Details can be found in Xin et al. (2012b).

(2) Decadal prediction on 10-30 yr time scale (decadalXXXX): Based on the set of simulations, Gao et al. (2012) evaluated the model’s prediction capability in regional and global surface temperatures on decadal time scale, and aimed to explore their dependences on the initial observed states of ocean in comparison with the historical experiment (historical). Results show that BCC_CSM1.1 can capture the warming trend of 10-year mean global surface temperature not only for oceanic initialization condition but also for without oceanic initialization condition. Nevertheless, the global warming trend simulated by BCC-CSM1.1 can be obviously decreased under the condition of oceanic initialization, closer to the observation than that in the historical experiment without oceanic initialization. After a “training” period of 8-12 months, predicted surface temperatures in the first year not only in ocean but also in land between 50°S and 50°N are close to CRU observations. The oceanic initialization does not significantly influence the prediction results and the variation of decadal-mean predicted SST is closely correlated with the surface heat flux.

(3) The last millennium experiment (past1000), covering the period from 850 A.D. to 2000 A.D (Zhang and Wu, 2012): The simulation can generally reproduce the three typical periods, i.e., Medieval Climate Anomaly epoch (MCA), Little Ice Age and the 20th century global warming period, and the upward trend in the 20th century is unprecedented in the past millennium context. External forcings act differently in modulating the climate both for the temporal variability and special structures. Persistent positive NAO phase in Medieval is consistent with reconstructions.

 Main Reference

Gao F., Xin X., Wu T. (2012) Study on the prediction of regional and global temperature in decadal time scale with BCC_CSM1.1 (in Chinese). Chinese Journal of Atmospheric Sciences (Abstract).
Wu T., Li W., Ji J., Xin X., et al. (2012a) The 20th century global carbon cycle from the Beijing Climate Center Climate System Model (BCC_CSM). Submitted to J. Climate (Full text)
Wu T (2012b). A mass-flux cumulus parameterization scheme for large-scale models: description and test with observations. Clim Dyn, 38, 725-744 (Full text)
Xin X., Wu T., Zhang J. (2012a) Introductions to the CMIP 5 simulations conducted by the BCC climate system model (in Chinese). Advances in Climate Change Research ( Abstract)
Xin X., Wu T., Li J., et al. (2012b), How well does BCC_CSM1.1 reproduce the 20th century climate change over China? Submitted to Atmospheric and Oceanic Science Letters (Full text)
Zhang J. and Wu T., (2012) The impact of external forcings on climate during the past millennium: Results from transient simulation with BCC_CSM1.1. Geophysical Research Abstracts, Vol.14, EGU2012-448. (Abstract)