2011年春季辽宁一次沙尘天气过程及其对不同粒径颗粒物和空气质量的影响

利用2011年5月11—12日辽宁沙尘天气过程的相关资料,分析了沙尘天气对不同粒径颗粒物及空气质量的影响及此次沙尘过程的天气成因.结果表明:沙尘天气发生前后可吸入颗粒物PM₁₀、PM_2.5和PM₁的浓度变化很大,沈阳、鞍山、本溪和丹东4城市PM₁₀、PM_2.5的小时浓度最大值都增大了1.5~20倍;粗粒子PM_(2.5~10)的数量浓度分别增加了30~41倍,质量浓度分别增加了27~30倍;细粒子PM_(1~2.5)的质量浓度分别增加了30~35倍,数量浓度分别增加了15~30倍;微粒子的数量浓度和质量浓度各城市表现不同,沈阳微粒子的数量浓度和质量浓度最大值增大了3倍和5倍,而鞍山PM₁的数量浓度和质量浓度分别减少了50%和10%.受蒙古气旋的影响内蒙古地区产生大风降温天气,大风将内蒙古地区的沙尘带到高空并随西风带向东移动进入辽宁,由于辽宁地区风速比较小,造成了辽宁大部分地区的浮尘天气,并对辽宁各地空气质量造成了严重影响,除丹东外辽宁其他13个城市空气质量都达到了轻微污染到重度污染的级别,铁岭、阜新、沈阳和抚顺的污染指数分别超过了300,达到了重度污染的级别.

The impacts on various particle sizes and the air quality caused by a dust weather process in Spring 2011 in Liaoning

Using data of a dust weather process in Liaoning during 11^th~12^th May 2011, the impacts on various particle sizes and the air quality caused by the dust weather and the cause of this dust weather process were analyzed. The results showed that the concentrations of PM₁₀, PM_2.5 and PM₁ were quite different before and after the dust weather process. When the dust weather occurred, the hourly maximum mass concentration of PM₁₀, PM_2.5 and PM₁ increased 1.5~20 times in the 4 cities of Shenyang, Anshan, Benxi and Dandong.The number concentrations of the coarse particles PM_(2.5~10) increased 30~41 times and the quality concentrations increased 27~30 times. The number of concentrations of the fine particles PM_(1~2.5) increased 27~30 times, and the mass concentrations increased 15~30 times. In addition, the number concentration and mass concentration of the ultrafine particle of PM₁ in each city were also different. The number concentrations of the ultrafine particles PM₁ increased 3 times, and the mass concentrations increased 5 times in Shenyang. But the number concentrations of the ultrafine particles PM₁ decreased 50%, and the mass concentrations decreased 10% in Anshan. Moreover, influenced by Mongolia Cyclone, the weather of Inner Mongolia became blustery and temperature dropped. The dust in Inner Mongolia was brought by the wind to high altitude and transported to Liaoning by westerlies. As surface wind speed in Liaoning was weak, floating dust influenced most parts of Liaoning, and the air quality in Liaoning was seriously affected. Except Dandong, air quality in the other 13 cities in Liaoning all reached the mild to serious pollution level. The air pollution index was more than 300 in Tieling, Fuxin, Shenyang and Fushun. Thus, air quality reached serious pollution level.