【摘要】 大孔径闪烁仪(large aperture scintillometer,LAS)的使用,提供了大气近地面层区域平均热通量测量的手段,但区域平均水汽通量的测量还是一个没有解决的重要问题。用LAS测量到的闪烁低频频谱和大气水汽起伏有关,和Nieveen的测量结果不同,在频谱的低端还测量到一个和吸收介质外尺度对应的拐角频率,因此更为合理。不同潜热通量时,折射率的结构常数在满足相似理论的条件下可以计算出来。分析表明LAS测量到的低频闪烁可能还和气溶胶的吸收和散射起伏有关。更多还原

【Abstract】 The means to measure area-averaged flux in the atmospheric surface layer is provided since large aperture scintillometer(LAS) was applied.The measurement technique of water vapor area-averaged flux is an important problem which is not solved so far.The behavior of low frequency range in the scintillation spectrum is probably related to fluctuations of water vapor.The spectra measured by LAS are different from the measurements of Nieveen.Another corner frequency was measured which is related to outer scale of absorb medium,so it is more reasonable.The structure parameter of refractive index imaginary part for the different latent heat flux was calculated by means of simulation theory.Analysis indicates that the low frequency range in the scintillation spectrum is also probably related to absorption and scattering fluctuations of aerosol.更多还原