雪面上光学湍流的测量与估算

 用合肥35 m铁塔测量系统，测量了2008年1月28 日至2月1日雪面上折射率结构常数，并用bulk方法和涡旋相关法估算了折射率结构常数，给出了大气层结稳定条件下的相似函数。结果表明：实验期间，大部分时间雪面上大气处于近中性和稳定状态；采用该相似函数，bulk方法和涡旋相关法估算的折射率结构常数与实测结果一致性很好；雪面上折射率结构常数也存在一定的日变化，但与草坪、海洋、沙漠等下垫面相比小1~2个量级，变化范围为1.9×10^-16~1×10^-14 m^-2/3。

Estimation and measurements of optical turbulence over snow

Eddy-covariance and profile measurements over snow were carried out at the 35 m tower in Hefei from Jan 28, 2008 to Feb 1, 2008. A similarity function was presented for the stable atmospheric stratification, and then refractive index structure parameter for the optical turbulence was estimated using eddy-covariance and bulk methods based on the function. Results show that the atmosphere near snow surface was nearly neutral and stable during most of the time in the experiment; with the presented similarity function, the estimate results using the two methods agree well with the measured one; the refractive index structure parameter over the snow cover ranged from 1.9×10-16 to 1×10-14 m-2/3, and exhibited a clear diurnal dependence like that over lawn, ocean and desert.