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Regional Characteristics of Dust Storms in China Weihong Qiana,*, Xutang A, Linsheng Quanb

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Regional Characteristics of Dust Storms in China Weihong Qiana,*, Xutang A, Linsheng Quanb ARTICLE IN PRESS AE International – Asia Atmospheric Environment 38 (2004) 4895–4907 Regional characteristics of dust storms in China Weihong Qiana,*, XuTang a, Linsheng Quanb a Department of Atmospheric Sciences, Monsoon and Environment Reseach Group, School of Physics, Peking University, Beijing 100871, China b Jinan Air Traffic Management Center of CAAC, Jinan 250107, China Received 25 March 2004; accepted 18 May 2004 Abstract Regional characteristics of dust storms in northern China are analyzed using a rotated empirical orthogonal function (REOF), based on the annual days of dust storms from 1954 to 1998. The relationships between regional dust storms corresponding to other factors such as precipitation and temperature are explored. The results show that five leading modes of dust storms exist in the following areas: the Taklamakan Desert (Tarim Basin) over the Xinjiang region (far northwestern China), the eastern part of Inner Mongolia (North China), the Tsaidam Basin, the Tibetan Plateau, and the upper reaches of the Yellow River (Gobi Desert). These areas are associated with an arid climate and frequent winds. For the first mode in the Tarim Basin, most dust storms appear in the 1980s, while dust storms become less frequent in the 1990s. The second mode (North China) shows the highest frequency of dust storms in the mid-1960s but the frequency decreases afterward. The third mode indicates a decreasing trend of annual dust storms after the mid-1960s but with a high interannual variability. The fourth mode also shows a decreasing trend but with a low interannual variability. The fifth mode displays a high frequency of dust storms in the 1970s followed by a decreasing trend. For the five modes of dust storm distribution, four of the centers are located in desert regions. The annual dust storms of a selected station in each mode region are shown to compare the coefficient time series of these modes. The negative correlation between the prior winter temperature and dust storm frequency is identified for most stations. There is no consistency in the correlation between the dust storm frequency and the annual rainfall as well as the prior winter rainfall at these stations. The activity of dust storms in northern China are directly linked to the cyclone activity, especially for the interdecadal variability. r 2004 Elsevier Ltd. All rights reserved. Keywords: Dust storms; Regional characteristics; China; Rotated empirical orthogonal function 1. Introduction northern parts of the country. In this region, the monsoon can cause not only drought/flood and cold/ As pointed out by Goudie and Middleton (1992), dust warm events, but also windy conditions and air storms have caused serious environmental consequences pollution (Xu, 2001; Jie, 1999; Goudie, 1983). The dust and hazards to human activities in different parts of the storm records in Chinese literature have been referred to world. China is located in the East Asian monsoon as ‘‘yellow wind’’, or ‘‘black wind’’ (Qian et al., 1997; region, where arid and semiarid climates dominate in the Wang et al., 1997; Zhang, 1997), as well as ‘‘dust rain’’ or ‘‘dust fog’’. The phenomena usually occur in the *Corresponding author. Tel.: +86-10-62767174; fax: +86- spring and early summer months (Qian, 1991). The 10-62751615. earliest known record of dust rain occurred in 1150 BC, E-mail address: [email protected] (W. Qian). as found in a historical book (after Liuet al., 1981 ). 1352-2310/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2004.05.038 ARTICLE IN PRESS 4896 W. Qian et al. / Atmospheric Environment 38 (2004) 4895–4907 Zhang (1984) used 1156 historical records to show the resulting in a reduced cyclone frequency in northern decadal frequency of dust rain years in China since AD China. The preceding winter temperature and spring 300. In the 1970s, several studies were conducted to cyclone number were used to construct a dust storm understand the dust storms in northern China, such as in index in eastern China. In the Tarim Basin, the high GansuProvince ( Xuet al., 1979 ). On 5 May 1993, a very frequency of dust storms has been attributed to strong dust storm (known as ‘‘5 May black wind’’) decreased precipitation and to the arid-hot climate. occurred in northwestern China and caused huge Geologically, several desert basins are situated in damage to human life and property. During the period northern China: the Xinjiang region in far northwest 1995–96, the Chinese government supported a project to China, the upper Yellow River valley in northwest investigate dust storms in northwestern China. A book China, and the eastern part of Inner Mongolia in entitled Study on the Duststorm in China was published northern North China (Fig. 1). These deserts are the by China Meteorological Press (Fang et al., 1997). In Taklamakan Desert and the Tsaidam Basin in the this book, a wide range of topics including the climatic Xinjiang region, the Gobi Deserts in the west of the characteristics, forecasting, remote monitoring, trans- upper Yellow River valley, the middle Yellow River port, deposition, numerical simulation, and service valley, and northern North China. The climatic condi- management of dust storms were discussed. However, tions such as precipitation, air temperature, and wind all of the studies were limited to case analyses. A (cyclone activity) may be mostly linked to the frequency systematic study of dust storms in China for a whole is of dust storms. The regional features of dust storms in still unseen and the long-term trend is unknown. The various areas over northern China can be related to reason for this is that the records of dust storms are these factors with different levels of significance. These individually stored at local stations and there is no regional features and relations were not investigated in statewide database of dust storms (Xuand Hu,1997 ). detail in our previous paper (Qian et al., 2002). This In our previous work, the interannual variability and paper will focus on the regional characteristics of dust long-term trend among dust storm frequency, dust storms and their relationships with other factors. After weather (including dust storms, dust haze, and blowing the introduction, a description of the data sets used in dust) frequency, air temperature, and cyclone frequency the study is given in Section 2. A rotated empirical in northern China were investigated using homogenous orthogonal function (REOF) is introduced in Section 3. data sets for several decades (Qian et al., 2002). It was The temporal–spatial distributions of dust storms found that the number of dust storms and dust weather derived from the REOF analysis of the dust storm data that occurred in the 1950s–1970s nearly doubled after for 1954–1998 are given in Section 4. The climate and the mid-1980s in northern China. The reason for this is dynamical control factors in the formation of dust that the warming in Mongolia and cooling in southern storms are discussed in Sections 5 and 6. Finally, a China reduced the meridional temperature gradient, discussion and summary are given in Section 7. Fig. 1. Locations of 135 stations in which dust storms were observed. The numerals mark major deserts: (1) for the Taklamakan desert in the southern Xinjiang region, (2) for the northern Xinjiang region, (3) for the Tsaidam Basin, (4) and (5) for the Gobi Desert in the west of the upper Yellow River valley, (6) for the Ordos Desert in the middle Yellow River valley, and (7) for northern north China. ARTICLE IN PRESS W. Qian et al. / Atmospheric Environment 38 (2004) 4895–4907 4897 2. Data description stations obtained from the China Meteorological Administration for 1950–98. The fourth data set In this paper, four data sets are used. The first data set contains the cyclone frequency (Qian et al., 2002) contains the dust events observed from stations. The derived from the National Center for Environmental data set of daily dust storms was obtained from the Prediction-National Center for Atmospheric Research China Meteorological Administration. Using the data (NCEP-NCAR) reanalysis of 850-hPa geopotential set of dust events from 338 stations for 1954–1998, the height (gph) with a horizontal resolution of 2.5 latitude yearly mean distribution of dust storms was shown in by 2.5 longitude. our previous work (Qian et al., 2002). The areas above Among the above four data sets, only those of one day of dust storm event per year cover northwest temperature and precipitation are from the same China and northern China except Heilongjiang Province stations while the other data sets are from different in northeast China. The high-frequency center with stations or grids. To discuss the relationship of dust more than 30 days of yearly dust storms is found in the storms with precipitation and temperature, only several Tarim Basin (Taklimakan Desert) region. Another stations are selected. To show the influence of cyclone center with yearly dust storms of more than 15–20 days activity, tracks of the cyclone movement are plotted and is situated in the central western Inner-Mongolia region. discussed. According to this coverage, we select the observed daily dust storms from 135 stations only covering northern China (Fig. 1). Based on the standards of surface 3. Method description meteorological observation (Central Meteorological Bureau, 1979), dust storms are the result of strong In China, dust storms are mainly concentrated in the turbulent wind systems entraining particles of dust into northern part of the country. Over this area, there are the air, reducing the visibility to 1000 meters and below. several centers of dust storm formation. These centers The standard of dust storms in China is the same as may be linked with local conditions such as deserts and described by Goudie and Middleton (1992).
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