用伪折射率和相似理论计算海上蒸发波导剖面

Modeling Evaporation Duct over Sea with Pseudo-Refractivity and Similarity Theory

本文说明了以伪折射率为相似参量用相似理论估算蒸发波导高度的理论方法 .由于海面附近折射率梯度变化可近似认为与气压无关 ,所以定义了伪折射率 ,推导了其相似公式 ,得到了蒸发波导高度满足的方程和一般文献都未给出的M剖面计算公式 .本文给出了本方法的计算机模拟典型结果、利用实测海洋资料计算的蒸发波导高度等参数的统计结果蒸发波导剖面以及海上折射率测量结果和本方法预测结果的对比结果等 ,这些结果表明本文给出的方法是有效的 .

The theoretic method used for calculating evaporation duct height is described based on similarity theory with pseudo-refractivity Np(h) as similarity variable. With the approximation of refractivity gradient independent of air pressure in the vicinity of sea surface, a parameter, the pseudo-refractivity Np (h) as we call, is defined. The M profile of evaporation duct, which is always not available in references, is given explicitly. The modeling results of evaporation duct height and the calculated results of evaporation duct parameters from the measured weather data are in agreement.