Variation characteristics of atmospheric aerosol optical depths and visibility in North China during 1980–1994
Variation characteristics of atmospheric aerosol optical depths and visibility in North China during 1980–1994
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DOI：
10.1016/s1352-2310(99)00173-9
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发表时间：
2000
影响因子：
5
通讯作者：
Jinhuan Qiu;Liquan Yang
中科院分区：
文献类型：
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作者：
Jinhuan Qiu;Liquan Yang
使用的方法是由邱建华(邱俊杰，1998)提出的。利用太阳总直接辐射确定大气气溶胶光学厚度的方法。J·艾莫斯。SCI。利用太阳直接辐射资料反演了中国北部5个气象站1980-1994年的气溶胶光学厚度，分析了气溶胶光学厚度和能见度的变化特征。这些观测站分布在乌鲁木齐、格尔木、哈尔滨、北京和郑州等城市。结果表明，1980-1994年间，五个测点的气溶胶光学厚度均呈增加趋势。在冬季，这一趋势更为强劲。在北京和乌鲁木齐的冬天，深度在15年内增加了大约两倍。燃烧化石燃料造成的污染是导致这一变化的主要原因。春季格尔木的深度较大，是四季中增加最快的，主要是由于沙漠沙尘事件所致。1991年皮纳图博火山喷发对气溶胶光学厚度有显著影响。与1990年相比，1992年喷发后5个测点的年平均埋深增加了0.068~0.212，而1992年至1994年总体呈下降趋势。在郑州、格尔木等城市，1980-1994年能见度和光学厚度均呈增加趋势，这可能是由于对流层气溶胶粒子垂直分布上移所致。在格尔木、哈尔滨、北京和郑州，夏季的光学厚度较大，这可能是由于潮湿的夏季生长的气溶胶粒子造成的。除格尔木外，其他四个地点冬季能见度较小，尤其是乌鲁木齐和哈尔滨。哈尔滨夏季能见度约为冬季的两倍，但深度相差不大，说明冬季对流层下部浑浊，夏季对流层上层消光系数较大。
Using a method developed by Qiu (Qiu, J., 1998. A method to determine atmospheric aerosol optical depth using total direct solar radiation. J. Atmos. Sci. 55, 734–758), 0.75μm aerosol optical depths at five meteorological observatories in north China during 1980–1994 are retrieved from global direct solar radiation, and variation characteristics of the depths and visibility are analyzed. These observatories are located in the cities of Wulumuqi, Geermu, Harbin, Beijing and Zhengzhou. It is found that during 1980–1994 the aerosol optical depths show an increasing trend at all five sites. During winter the trend is stronger. In winter at Beijing and Wulumuqi, the depth increased by a factor of about two in 15 years. Pollution caused due to the burning of fossil fuel is the main cause of the change. In spring at Geermu the depth is larger and its increase is the quickest among the four seasons, mainly due to desert dust events. The Pinatubo volcanic eruption in 1991 had a significant influence on the aerosol optical depth. The yearly averaged depths over five sites in 1992 after the eruption increased by 0.068 to 0.212, compared to those in 1990, while from 1992 to 1994 they generally show a decreasing trend. In some cities such as Zhengzhou and Geermu, both visibility and optical depth show an increasing trend during 1980–1994, a possible reason for this is that the aerosol particle vertical distribution shifts up in the troposphere. At Geermu, Harbin, Beijing and Zhengzhou, optical depths in summer are larger, which may be because of the growth of aerosol particles growing in the moist summer. Apart from Geermu, at the other four sites visibility in winter is smaller, especially at Wulumuqi and Harbin. At Harbin, visibility in summer is about twice larger than that in winter, but the difference between depths is small, implying the turbid lower troposphere in winter and the larger extinction coefficient in the upper troposphere during summer.