Climate and Circulation Characteristics of Dust Weather in Gonggar, Tibet, China
Received date: 2014-06-17
Revised date: 2014-08-27
Online published: 2015-09-20
Using dust weather data including flowing dust, blowing sand and sandstorm in Gonggar of Tibet Autonomous Region of China from 1978 to 2012, the dust weather climate and circulation characteristics in Gonggar was analyzed. The result shows that dust weather most occurred in winter and spring, less in autumn, rarely in summer; blowing sand and sandstorm mainly occurred in the afternoon, and the flowing dust occurred throughout the day; blowing sand and sandstorm showed a fluctuating decreasing trend at the rate of approximately 7 d-10a and 2.2 d-10a, respectively, flowing dust increased insignificantly with 0.5 d/10a trend in the recent 35 years. Qualitative analysis showed sand/dust source areas of dust weather in Gonggar included Gonggar, Nimu, Namling, Shigatse, and Lhatse by using infrared difference dust index (IDDI) spatial distribution data and ground wind field data, and sandy land distribution data from 2005 to 2012. Small relative humidity, high wind speed, and long consecutive days without precipitation caused dust weather, and atmospheric circulation pattern can be divided into 4 categories: blocking pattern (40%), dry southern branch trough pattern (17%), northwest flow pattern (26%) and thermal low pressure pattern (17%).
Key words: Gonggar; dust weather; climate characteristics; general circulation type
Lin Zhiqiang , Wang Pengxiang , Tang Shuyi , Zhou Zhenbo , Yang Limin . Climate and Circulation Characteristics of Dust Weather in Gonggar, Tibet, China[J]. Journal of Desert Research, 2015 , 35(5) : 1312 -1319 . DOI: 10.7522/j.issn.1000-694X.2014.00124
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