Acta Scientiarum Naturalium Universitatis Pekinensis ›› 2021, Vol. 57 ›› Issue (1): 121-131.DOI: 10.13209/j.0479-8023.2020.092

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Coupled Model Studies of the Tibetan Plateau Effect on the Atlantic Meridional Overturning Circulation under Different Resolutions

SHAO Xing, YANG Haijun, LI Yang, JIANG Rui, YAO Jie, YANG Qianzi   

  1. Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871
  • Received:2020-01-10 Revised:2020-05-14 Online:2021-01-20 Published:2021-01-20
  • Contact: YANG Haijun, E-mail: hjyang(at)pku.edu.cn

不同分辨率下青藏高原对大西洋经向翻转流影响的耦合模式研究

邵星, 杨海军, 李洋, 姜睿, 姚杰, 杨千姿   

  1. 北京大学气候与海?气实验室, 北京大学物理学院大气与海洋科学系, 北京 100871
  • 通讯作者: 杨海军, E-mail: hjyang(at)pku.edu.cn
  • 基金资助:
    国家自然科学基金(91737204, 41376007, 41725021)资助

Abstract:

The effect of Tibetan Plateau on the Atlantic Meridional Overturning Circulation (AMOC) under different resolutions is studied using the coupled Community Earth System Model (CESM1.0). Comparation of the results with and without the Tibetan Plateau tests shows that the changes of AMOC after the removal of the Tibetan Plateau are related to the resolution of the model. Under different resolutions, the changes of AMOC are inconsistent: AMOC Index decreases by 89% in the low resolution test, but only by 13% in the high resolution test. The reason for this difference is that there are significant differences in the changes of location and strength of the mixed layer subduction, which contributes to the deep water formation under different resolution test: the low resolution test is mainly located in the GIN seas, while the high resolution test is mainly located in the Labrador Sea. After removing the Tibetan Plateau, the subduction of both tests decreases, but the decrease of the low resolution test is larger than that of high resolution test. The subduction in the Labrador Sea of high resolution test decreases the most obviously, while the subduction in all sea areas decreases in the low resolution test, especially in the GIN seas. Comparation of the observed wind data and latest observational studies of deep water formation area over the North Atlantic shows that the results of low resolution coupled model are more similar to the actual observations in the seas studied in this paper.

Key words: Tibetan Plateau, Atlantic Meridional Overturning Circulation (AMOC), subduction, model resolution

摘要:

利用耦合地球系统模式CESM1.0, 探究不同分辨率下青藏高原对大西洋经向翻转流(AMOC)的影响。对比有青藏高原地形与无青藏高原地形的试验, 发现移除青藏高原后AMOC的变化与模式分辨率有关, 不同分辨率下AMOC的变化不一致, 低分辨率试验中AMOC强度降低 89%, 高分辨率试验中仅降低13%。产生这种差异的原因是, 不同分辨率下对深水形成有重要贡献的混合层潜沉位置和强度的变化显著不同: 低分辨率试验主要位于格陵兰海?冰岛海?挪威海(GIN), 高分辨率试验主要位于拉布拉多海, 移除青藏高原后, 高、低分辨率试验中潜沉均减弱, 但低分辨率试验中减弱幅度大于高分辨率试验, 高分辨率试验中位于拉布拉多海的潜沉强度减弱最明显, 低分辨率试验中所有海域的潜沉强度均减弱, GIN海域尤其明显。模拟结果与观测风场数据以及北大西洋深水形成最新观测结果的对比表明, 在所研究海域, 低分辨率耦合模式的模拟结果更接近观测值。

关键词: 青藏高原, 大西洋经向翻转流(AMOC), 潜沉, 模式分辨率