Community Integrated Earth System Model (CIESM): Description and Evaluation

• Main Authors: Yanluan Lin, Xiaomeng Huang, Yishuang Liang, Yi Qin, Shiming Xu, Wenyu Huang, Fanghua Xu, Li Liu, Yong Wang, Yiran Peng, Lanning Wang, Wei Xue, Haohuan Fu, Guang Jun Zhang, Bin Wang, Ruizhe Li, Cheng Zhang, Hui Lu, Kun Yang, Yong Luo, Yuqi Bai, Zhenya Song, Minqi Wang, Wenjie Zhao, Feng Zhang, Jingheng Xu, Xi Zhao, Chunsong Lu, Yizhao Chen, Yiqi Luo, Yong Hu, Qiang Tang, Dexun Chen, Guangwen Yang, Peng Gong
• Format: Article
• Language: English
• Published: American Geophysical Union (AGU) 2020-08-01
• Series: Journal of Advances in Modeling Earth Systems
• Subjects: Community Integrated Earth System Model; preindustrial and historical simulations; coupled model evaluation
• Online Access: https://doi.org/10.1029/2019MS002036

Abstract A team effort to develop a Community Integrated Earth System Model (CIESM) was initiated in China in 2012. The model was based on NCAR Community Earth System Model (Version 1.2.1) with several novel developments and modifications aimed to overcome some persistent systematic biases, such as the double Intertropical Convergence Zone problem and underestimated marine boundary layer clouds. Aerosols' direct and indirect effects are prescribed using the MACv2‐SP approach and data sets. The spin‐up of a 500‐year preindustrial simulation and three historical simulations are described and evaluated. Prominent improvements include alleviated double Intertropical Convergence Zone problem, increased marine boundary layer clouds, and better El Niño Southern Oscillation amplitude and periods. One deficiency of the model is the significantly underestimated Arctic and Antarctic sea ice in warm seasons. The historical warming is about 0.55 °C greater than observations toward 2014. CIESM has an equilibrium climate sensitivity of 5.67 K, mainly resulted from increased positive shortwave cloud feedback. Our efforts on porting and redesigning CIESM for the heterogeneous Sunway TaihuLight supercomputer are also introduced, including some ongoing developments toward a future version of the model.