沙尘天气对北京大气环境质量及太阳辐射的影响

Influence of Dust Events on Atmospheric Environmental Quality and Solar Radiation in Beijing

利用空气污染指数(API)、地面气象数据和辐射观测数据,分析了2009年3月一次典型沙尘天气发生时的大气环境质量及太阳辐射变化,并分析了2008年10月—2009年6月不同污染情形下各太阳辐射要素之间的关系.结果表明:API与辐射关系明显,沙尘天气导致总辐射、直接辐射和反射辐射减小.净辐射白天减小而夜间增大.能见度和气压等气象要素对沙尘过程影响明显.沙尘到来时,能见度降低,地面处于低气压控制下;沙尘过境后地面被高压控制.随着污染的加重,总辐射与反射辐射相关关系显著,变化不大但略有偏差;直接辐射和总辐射、散射辐射、反射辐射的相关性先降低后增加;散射辐射与总辐射的比值持续增大,但增加的速度随着污染的加重趋于平缓,且离散度增大.

Based on the air pollution index（API）,meteorological data and radiation data,this paper analyzed the varying characteristics of atmospheric environmental quality and solar radiation during a typical dust event in March 2009.Further research was then performed on the relation between different radiation factors in different pollution situations occurring from October 2008 to June 2009.The results show that API is significantly correlated with radiation.The dust events led to a decrease of total radiation,direct radiation and reflected radiation.The net radiation decreased in daytime and increased in nighttime.The results show a good response relationship between visibility,atmospheric pressure at sea level and dust events.When dust events came,the visibility decreased and the ground was under low-pressure control;after the dust events passed through,the ground became under high-pressure control.As the pollution became aggravated,the correlation between total radiation and reflected radiation remained significant with little change.In contrast,the correlations between other radiation factors-including total radiation and direct radiation,direct radiation and diffused radiation,and direct radiation and reflected radiation-first decreased and then increased.The quotient of diffused radiation and total radiation increased continuously and then showed a stable trend,though thestandard deviation was higher.