张宇, 李铁键, 李家叶, 钟德钰. 西风带和南亚季风对三江源雨季水汽输送及降水的影响[J]. 水科学进展, 2019, 30(3): 348-358. DOI: 10.14042/j.cnki.32.1309.2019.03.005
引用本文: 张宇, 李铁键, 李家叶, 钟德钰. 西风带和南亚季风对三江源雨季水汽输送及降水的影响[J]. 水科学进展, 2019, 30(3): 348-358. DOI: 10.14042/j.cnki.32.1309.2019.03.005
ZHANG Yu, LI Tiejian, LI Jiaye, ZHONG Deyu. Intercomparison of high-accuracy water level gauges in the scale of small experimental catchment[J]. Advances in Water Science, 2019, 30(3): 348-358. DOI: 10.14042/j.cnki.32.1309.2019.03.005
Citation: ZHANG Yu, LI Tiejian, LI Jiaye, ZHONG Deyu. Intercomparison of high-accuracy water level gauges in the scale of small experimental catchment[J]. Advances in Water Science, 2019, 30(3): 348-358. DOI: 10.14042/j.cnki.32.1309.2019.03.005

西风带和南亚季风对三江源雨季水汽输送及降水的影响

Intercomparison of high-accuracy water level gauges in the scale of small experimental catchment

  • 摘要: 为了进一步明确西风带和南亚季风对三江源流域的水汽输送作用及对流域降水的影响,利用ERA-20C再分析数据集对三江源流域1948-2010年雨季水汽通量场进行经验正交函数(Empirical Orthogonal Function,EOF)分解,得到可表征西风带和南亚季风水汽输送在三江源流域强弱关系的经验正交函数模态及指标,揭示当西风带和南亚季风分别控制流域时的水汽输送和降水分布规律。结果表明:西风带控制流域水汽输送时,流域内部水汽输送方向为由西北向东南,西风带和南亚季风在流域南边界附近汇集,流域东部及南部(澜沧江源区大部,黄河源区东部)降水显著增加;南亚季风控制流域水汽输送时,流域内部水汽输送方向为由南向北,两支水汽输送路径在流域以北汇集,流域北部(长江源区大部,黄河源区偏北部)降水显著增加。西风带和南亚季风的水汽输送均对三江源流域具有重要作用,两支水汽输送路径分别控制流域时可引起流域内部不同区域降水的显著增加。

     

    Abstract: This study further clarified the influence of the westerlies and the South Asia monsoon on both the water vapor transport and precipitation in the Three-River Headwaters Region. ERA-20C reanalysis datasets were used to perform an empirical orthogonal function (EOF) decomposition of the water vapor transport flux of the Three-River Headwaters Region during the rainy seasons of 1948-2010. The EOF mode and index were acquired that can indicate whether the water vapor transport in the investigated region is controlled by the westerlies or the South Asia monsoon. The spatial patterns of water vapor transport and precipitation in the region were found under control of the westerlies or the South Asia monsoon. Under control of the westerlies,the water vapor transport direction inside the region was NW-SE. The westerlies and the South Asia monsoon converged at the south boundary of the region;furthermore,precipitation increased significantly in the east and south of the region (i.e.,the majority of the Lancang River headwater and east of the Yellow River headwater). Under control of the South Asia monsoon,the water vapor transport direction was S-N,the two water vapor transport paths converged in the north,and precipitation increased significantly in the north (i.e.,the majority of the Yangtze River headwater,and the north of the Yellow River headwater). The westerlies and the South Asia monsoon both exerted a vital influence on precipitation in the Three-River Headwaters Region. Water vapor transport paths controlled by either the westerlies or the South Asia monsoon led to positive precipitation anomalies in different parts of the region.

     

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