Journal of Arid Meteorology ›› 2021, Vol. 39 ›› Issue (3): 374-385.

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A Study of Spatial and Temporal Distribution of Land Atmosphere Coupling Strength in China

YANG Yang1, YANG Qidong2, WANG Zhilan1, GAO Lu2   

  1. 1. Institute of Arid Meteorology, CMA, Lanzhou 730020, China; 2. Department of Atmosphere
     Science, School of Earth Sciences, Yunnan University, Kunming 650500, China
  • Online:2021-06-30 Published:2021-07-16



  1. 1.中国气象局兰州干旱气象研究所,甘肃兰州730020;

Abstract: The land-atmosphere coupling (LAC) strength can be used to characterize how the land surface influences precipitation, temperature or other atmospheric physical processes, and can be used to identify the hotspot of land-atmosphere interactions, which can deepen the understanding of landatmosphere interaction and climate system. In order to quantify the LAC strength in China, the spatial-temporal distribution characteristics of the LAC index of soil moisturelatent heat flux and latent heat flux-lifting condensation level, the Pearson and Kendall’s Tau correlation of soil moisturetemperature and soil moistureprecipitation were analyzed by using ERA5 reanalysis data. The results are as follows: (1) The latent heat flux increased with soil moisture increasing, providing water vapor for precipitation. The increase in latent heat flux led to the decrease of sensible heat flux, then temperature decreased, which weakened the drive of boundary layer and was not conducive to the uplift and condensation of air mass over arid and semiarid areas of northern China. This region was a hotspot of landatmosphere interaction in China. (2) There were obvious seasonal differences in LAC strength in China. The LAC strength over arid and semiarid regions was stronger in spring and summer, but weaker in autumn and winter. The soil was relatively dry in dry season over southwest China where LAC was significant. For landatmosphere coupling, we should not only consider the division of traditional climate zones, but also ponder the influence of rain belt dynamic changes.

Key words: land-atmosphere coupling strength, hotspot, correlation analysis, land-atmosphere coupling index

摘要: 使用陆气耦合强度来表征陆面状态对降水、气温或大气其他物理过程的影响程度,可以辨识陆气相互作用的热点地区,加深对陆气相互作用和气候系统的认识。利用ERA5再分析资料,结合Pearson相关系数、Kendall’s Tau相关系数及土壤湿度-潜热通量、潜热通量-抬升凝结高度的陆气耦合指数对中国区域陆气耦合强度进行定量分析。结果表明:(1)我国北方干旱半干旱区土壤湿度增大导致潜热通量增加,为降水提供了所需的水汽条件;潜热通量增大导致感热通量减小,温度降低,对边界层的驱动减弱,不利于气团的抬升凝结,该区域是我国陆气相互作用的热点地区。(2)我国陆气耦合强度存在显著的季节性差异。干旱半干旱区陆气耦合强度在春夏季较强,秋冬季较弱。西南地区春季土壤湿度较低,有显著的陆气相互作用。

关键词: 陆气耦合强度, 热点地区, 相关分析, 陆气耦合指数