JOURNAL OF NATURAL RESOURCES ›› 2014, Vol. 29 ›› Issue (1): 117-128.doi: 10.11849/zrzyxb.2014.01.011

• Resources Evaluation • Previous Articles     Next Articles

Diurnal Variation of 500 hPa Zonal Wind in Summer over the Tibetan Plateau and Analysis of Its Impact

ZHU Li-hua, FAN Guang-zhou, ZHOU Ding-wen   

  1. Academy of Atmospheric Sciences, Plateau Atmosphere and Environment Key Laboratory of Sichuan Province, Chengdu University of Information Technology, Chengdu 610225, China
  • Received:2012-05-22 Revised:2013-08-22 Online:2014-01-20 Published:2014-01-09

Abstract: Using the linear-trend estimate, composition and correlation analysis, the diurnal variability of the 500 hPa zonal wind in summer over the Tibetan Plateau and its impact are examined, based on the NCAR/NCEP reanalysis and the twice-daily precipitation data from 142 stations in China. The results reveal that: 500 hPa zonal wind at day and night in summer over the Tibetan Plateau overall show a decreasing trend since 1950, and it is more notable at night. The daily range of zonal wind show a decreasing trend. Zonal winds at day and night over the Tibetan Plateau all have a pronounced abrupt weakening occuring in 1967. The diurnal changes of zonal wind over the Tibetan Plateau have pronounced abrupt reduction occuring in 1965 and greater occuring in 1975. The diurnal change of zonal wind presents the periods about 4-6 years and 16-23 years. When the zonal wind is abnormal, anomalous ascending or descending flow are found at the east flank of the plateau and areas east of it. When the zonal wind decreases, less precipitation happens in areas north of the Yangtze River, while more precipitation happens in areas south of it. The diurnal variation of response of precipitation to anomalous zonal wind over the Tibetan Plateau is mainly in diurnal variation of the anomalous precipitation over the eastern and the western Sichuan Basin.

Key words: zonal wind, Tibetan Plateau, precipitation, climatic variation, diurnal variation, circulation

CLC Number: 

  • P467