参与光化学反应的物质对UV能量吸收的估算

在对北京紫外辐射(UV)观测资料分析的基础上,提出参与光化学反应的物质对UV能量具有吸收作用.计算了1990年12个月实际天气比晴天UV能量的减少值在64～109 W/m2之间,这一减少受臭氧、"水汽"、气溶胶等因子的衰减分别为39.1～66.3,21.5～36.5,3.2～5.5 W/m2(12月除外),12个月的平均值分别为48.3,26.6,4.0 W/m2.计算结果表明,云天大气对UV能量有衰减,其衰减能量中有26.6 W/m2是"水汽的作用",即参与大气光化学反应的物质对UV能量吸收所造成的,此计算值同国外观测与模式的研究结果比较接近.由于现有模式中还没有考虑这一部分能量,所以造成模式结果与观测结果间较大的差异. 

Estimation of UV Energy Absorption by the Substances in Photochemical Reactions

On the basis of analyzing UV observation data,it is put forward that substances in the atmosphere can absorb UV energy.The calculated UV energy loss in the actual sky compared to clear sky in 1990 was 64～109 W/m\+2,this UV energy loss attenuated by ozone,“water vapor" and aerosol was 39 1～66 3,21 5～36 5 and 3 2～5 5 W/m\+2 respectively (except December), and yearly averaged values were 48 3, 26 6 and 4 0 W/m\+2 respectively.The result shows that cloudy atmosphere absorbs UV energy,and there is 26 6 W/m\+2 lost in the cloudy atmosphere,because of the role of “water vapor",i.e.the UV energy absorption by substances in the atmosphere when they take part in photochemical reactions.The calculated value agrees with the observed and modeled results abroad.Because existing models have not taken this part of energy into full consideration,there is a significant difference between modeled and observed results.