摘要
依靠云滴的射线光学模型,针对具有吸收的耗散介质,可得到形式完整的电磁波反射系数公式,并且可求得具有几何意义的实际折射角。文中重点讨论了云滴中污染内含物及其不同的内混合方式对光化通量增强因子的影响。结果表明:云滴的存在都能增强光子的光化通量,仅当吸收系数非常大时,云滴内光化通量才会减小;无论哪一种内混合方式,受污染的云滴内光化通量增强基本上稍大于先前的估计值;光化通量增强因子一般都在1.2～1.62之间,即光化通量增加了20%～62%;吸收系数为零时,增强因子与云滴半径无关;增强因子随云滴半径和吸收系数的增大而减小。当云滴半径接近1μm时,吸收系数的影响迅速减小。
Based on the ray optics model of water droplet, a set ofreflectance coefficient and meaningful refractive angle for the absorbing material are derived by a somewhat different treatments from previous one. The dirty cloud droplet polluted by highly absorbing inclusions can enhance the actinic flux, unless the absorptive coefficient very big. The results from effective medium approximations show that our actinic flux enhancement is larger than earlier ones. The values generally stay between 1.2～1.62. That is to say the droplet enhances the actinic flux by some 20% to 62%. In addition, the actinic flux enhancement factor will reduce as the absorptive coefficient and droplet radius increase. However, when the two impact parameters become very small this influence will get weaker and weaker.
出处
《高原气象》
CSCD
北大核心
2003年第3期281-287,共7页
Plateau Meteorology
基金
中国科学院知识创新工程重要方向项目(KZCX2 201)资助
