昆明地面生物有效紫外辐照度的初步计算

A Preliminary Calculation on the Surface Biologically -Active UV Irradiance for Kunming by the Two-Stream Approximation

近年来，大气平流层臭氧含量普遍呈下降趋势。这将对人类的生存环境构成极大威胁，应当引起人们的高度重视。其中，太阳紫外辐射是一大因素。太阳紫外光（ＵＶＢ和ＵＶＡ，尤其是波长为２８０～３２０ｕｍ）对动植物生长及人类健康具有重要的生物学效应．但太阳光在大气中的传输过程极其复杂，涉及到大气臭氧吸收、空气分子散射、气溶胶颗粒以及云滴的散射等作用。针对昆明地处低纬高原、季风云系影响显著等特点，本文在同时考虑上述几种情况下，用二流模式（ｔｗｏ—ｓｔｒｅａｍｍｏｄｅｌ）方法对太阳紫外辐射传输问题进行了研究，得出了一些有意义的计算结果，并对其作了讨论。

Recent reports of the stratospheric ozone depletion have caught concerns about the levelsof solar ultraviolet radiation at the earth's surfaCe. A preliminary calculation on the surfacebiologically- active UV irradiance (UVB and UVA) in Kunming area, using a two-stream model, isdescribed in this paper. In the model, the influences of ozone absorption, Rayleigh scattering, clouddroplet scattering, aerosol scattering and their seasonal variations are considered. Finally, the calculatedresults including speCtral and integral,surface irradiances are discussed.