東亞沙塵暴的時空特徵分析

On the Space-time Characteristics of East Asian Dust Storms

余嘉裕(Jia-Yuh Yu) ； 卓盈旻(Yin-Ming Cho) ； 涂建翊(Jien-Yi Tu)

《環境保護》 25卷2期 (2002/12) Pp. 178-198

https://doi.org/10.30017/EP.200212.0005

摘要

本文利用亞洲FGGE地面綜觀天氣觀測資料、NCEP大氣網格點資料、東亞地面天氣圖、以及TOMS懸浮微粒指數資料分析東亞地區沙塵暴活動發現，東亞地區每年平均發生17次移動型沙塵暴，以春季（3~5月）發生頻率最高，佔了全年總數之75%左右，其中強和特強沙塵暴就佔了春季沙塵暴總數之35%左右，對東亞地區空氣品質有顯著之衝擊。
研究結果也顯示，東亞沙塵暴主要移動路徑有二支：第一支路徑往東，佔了所有個案之88%，主要順著高空槽東移將強風區與沙塵往東北、韓、日方向輸送，對台灣地區空氣品質影響較小。第二支路徑往東南移動，佔了所有個案之33%，需要透過分裂高壓南下將沙塵往東南輸送，對台灣地區空氣品質有嚴重之衝擊。
懸浮微粒指數之經驗正交函數分析也證實沙塵暴主要輸送路徑為東向移動，往東南移動之部分較弱，但在強或特強沙塵暴較為活躍年份（如2000年），往東南輸送之部分將顯著增加。

並列摘要

In this paper, FGGE surface weather codes, NCEP grid data of atmosphere, surface weather maps, and TOMS aerosol index data are used to investigate the East Asian dust storm activity. An average of 17 dust storms per year is found in East Asia. About 75% of the annual dust storms occur in spring season (March to May), and among them about 35% are either strong or severe cases, which exhibit significant influence on East Asian air quality.
Two notable routes are found for the East Asian dust storms. The first route, accounting for 88% of all cases, transports dust eastward by the eastward advection of low-troposphere trough, and its path passes over Northeast China, Korea, and Japan. The second route, accounting for 33% of all cases, transports dust southeastward by the split High and shows marked impact on air quality over Taiwan.
Empirical Orthogonal Analysis of aerosol index shows that eastward propagation is the major route for East Asian dust storms. The south-eastward propagation is relatively weaker compared to the previous route. However, during active duststorm years (e.g., year 2000), the south-eastward propagation component will be significantly enhanced.