FGOALS_g1.1极地气候模拟

Polar climate simulation in FGOALS_g1.1. Polar cli mate simulation in FGOALS-g1.1.

中文关键词:  气候系统模式， 海冰， 大气， 海洋， 模式评估

英文关键词:Climate system model, Sea ice, Atmosphere, Ocean, Model evaluation

中文摘要:

      对中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室发展的气候 系统模式FGOALS-g1.1的极地气候模拟现状进行了较为全面的评估。结果表明，FGOALS- g1.1对南北极海冰的主要分布特征、季节变化和年代际变化趋势具有一定的模拟能力。但也 注意到，与观测相比，模式存在以下几方面的问题：(1) 模拟的海冰总面积北极偏多，而南 极偏少。北极，北大西洋海冰全年明显偏多；夏季，西伯利亚沿海海冰偏多，而波弗特海 海冰偏少。南极，威德尔海和罗斯海冬季海冰偏少。南北极海冰边缘都存在异常的较大范 围密集度很小的碎冰区，夏季尤为显著。(2) 海冰流速在南北极海冰边缘和南极大陆沿岸附 近较大。北极，模式没能模拟出波弗特涡流，并且由于模式网格中北极点的处理问题，造成 其附近错误的海冰流场及厚度分布。这些海冰偏差与模式模拟的大气和海洋状况有着密切的 联系。进一步分析表明，FGOALS-g1.1模拟的冰岛低压和南极绕极西风带明显偏弱， 其通过大气环流和海表面风应力影响向极地的热量输送，在很大程度上导致上述的海冰偏差 。此外，耦合模式中大气-海冰-海洋的相互作用可以放大子模式中的偏差。

英文摘要:

      The polar climate simulations (with emphasis on sea ice) in the latest version o f LASG climate system model (FGOALS-g1.1) were evaluated using a variety of observational data. The results show that FGOALS-g1.1 does a reasonable job i n simulating primary characteristics of the Arctic and Antarctic sea ice, includ ing spatial distribution, seasonal variation, and decadal trend. However, some d iscrepancies are noteworthy. (1) FGOALS-g1.1 produces more (less) total seaice area in the Arctic (Antarctic) as compared to the observations. In the Arctic, there is excessive (insufficient) ice cover in north Atlantic all year long, an d in east Siberia Sea (Beaufort Sea) in summer. In the Antarctic, there is insuf ficient ice cover in the Weddell and Ross Seas in winter. Extremely large area w ith small ice concentration is found far beyond the sea ice edge zone in both th e Arctic and Antarctic, particularly in summer. (2) The simulated sea ice velo city is systematically too large as compared to the observations, mainly near th e sea ice edge in both the Arctic and Antarctic as well as near Antarctic coasta l regions. In the Arctic, the model can not capture the Beaufort Gyre, and produ ce unrealistic ice motion and thickness distribution around the North Pole due t o the impropriate way to handle the North Pole. Biases in sea ice simulations id entified here are closely associated with how well the simulations are in atmosp here and ocean components of FGOALS-g1.1. Further analyses show that weak Icel andic Low and Antarctic Circumpolar Westerly simulated in FGOALS-g1.1 partly c ontribute to the aforementioned biases in sea ice simulations through influencin g atmospheric and oceanic poleward heat transport. Additionally, the amplificati on of biases in the subcomponent of FGOALS-g1.1 due to atmosphere sea ice oc ean interaction is briefly discussed.