全球冰-海洋耦合模式的海冰模拟

海冰是全球气候系统的重要分量 ,与大气和海洋的相互作用 ,直接影响大气环流和海洋环流 ,对气候及其变化具有重要影响。文中依据冰、海洋间的热力、动力耦合相互作用 ,改进冰海洋热力耦合方案 ,利用由中国科学院大气物理研究所的 30层海洋模式和基于Flato空化流体流变学的海冰动力模式和Hibler表面热收支平衡的零层海冰热力模式 ,建立全球冰海洋耦合模式。利用大气月平均气候资料 ,利用冰海洋耦合模式对全球海冰的分布及其季节性变化、海冰漂移进行了耦合模拟和分析。模拟的南半球海冰分布及季节变化与实际分析资料非常接近 ,比 2 0层冰海洋耦合模式的结果有显著改进。北半球海冰范围偏小 ,但季节变化的量值与实际相当一致。模拟的海冰速度场反映了南、北半球海冰漂移的主要特征 ,如北极的穿极漂流和南大洋的绕极环流等。对海冰密集度的分析表明 ,模拟结果得以改进原因在于改进的冰海洋热力耦合方案增强了融冰期冰海洋耦合系统海洋热通量增加—密集度减小—能量收支增加的正反馈机制。

GLOBAL SIMULATION OF SEA ICE WITH A COUPLED ICE-OCEAN MODEL

As a major component of the climate system,the sea ice plays an important role in the climate change. The air\|ice\|sea interaction and their feedback mechanisms have directive effect on the general atmospheric circulation and the general oceanic circulation. A coupled global ice\|ocean model is developed by coupling a dynamic\|thermodynamic sea ice model with the world ocean circulation model of LASG/IAP, on the basis of research on the ice\|ocean interaction and improving the coupling of thermodynamics processes between ice and ocean. The sea ice model is based on the Flato's cavitating fluid rheology and is also based on the Hibler's heat\|balance zero\|layer thermodynamics ice model. The global distribution, drift and seasonal variation of the sea ice are simulated and analyzed by using the monthly climatic atmospheric data. The seasonal variation and distribution of sea ice are successfully reproduced and the simulated results by using the coupled model are closer to the observation in the Southern Hemisphere than that by a coupled model of sea ice model with the 20\|layer ocean model. The extent of simulated ice in the northern hemisphere is a little less than the observation, but the simulated seasonal variations agrees with the observation. It is shown from the ice concentration that the global simulation of sea ice can be improved by the new coupling scheme through intensifying the positive feedback mechanism related to the oceanic heat flux, ice concentration/extent and heat budget of the upper ocean layer.