Acta Geographica Sinica ›› 2005, Vol. 60 ›› Issue (1): 12-20.doi: 10.11821/xb200501002

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Influences of Synoptic Variability on Spring Sand Storm Frequency in North China

MAO Rui1, GONG Daoyi1, FAN Yida2   

  1. 1. Key Laboratory of Environmental Change and Natural Disaster, College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China;
    2. Division of Satellite Remote Sensing, Chinese Disaster Reduction Center, Beijing 100053, China
  • Received:2004-08-10 Revised:2004-11-16 Online:2005-01-25 Published:2005-01-25
  • Supported by:

    EYTP-1964; Huo Yingdong Education Foundation, No.81014

Abstract:

Based on the European Center for Medium-Range Weather Forecasts reanalysis datasets and the observed data for dust storms in North China, the authors investigated the relationships between dust storm frequency, monthly mean geopotential heights and synoptic variance in middle to lower troposphere for the period 1962 to 2000. The result shows that there is significant negative correlation between spring dust storm frequency and mean 500 hPa geopotential heights in mid-high latitude of East Asia, with correlation centers appearing in the Mongolia and Siberia. That suggests that this particular circulation pattern is likely to cause more cold air activities originating from the high latitudes and consequently result in frequent dust storms in North China. Weather process is the main reason for dust storm. The synoptic variance in East Asia shows evident year-to-year variations and long-term trends. There is significant relationship between synoptic variance and dust storm frequency. Their temporal changes are in phase. In addition, dust storm frequency is strongly correlated with the cyclone frequency (defined as the extremely low 850 hPa heights below the 10 percentiles) and the surface cold highs. It was found that the Northeast Low and cold surge activities of Mongolia and Siberia exert notable influence on dust storm frequency. Synoptic variance in East Asia shows a remarkable decreasing trend in 1962-2000 that explains a large portion of the decreasing in dust storm frequency. In addition, Arctic Oscillation may, in part, play a role in influencing the interannual variations of the synoptic variance and dust storm activities.

Key words: synoptic variance, dust storm, North China