Voss Kenneth J, Flora Stephanie
Physics Department, University of Miami, Coral Gables, Fl. 33124.
Moss Landing Marine Laboratory, San Jose State University, 95039.
J Atmos Ocean Technol. 2017 Jun;34(6):1203-1205. doi: 10.1175/JTECH-D-17-0040.1. Epub 2017 May 30.
The transmission coefficient, , commonly used to propagate the upwelling nadir radiance, just below the ocean surface, to above the surface has been assumed to be a constant value of 0.543 in seawater. Because the index of refraction of seawater varies with wavelength, salinity, and temperature, the variation of with these parameters should be taken into account, especially if low uncertainty is required for the quantities derived using . In particular the wavelength dependence of this factor is important. For example at a salinity of 35 g/kg and a temperature of 26° C, will be 1.3% lower at 380 nm and 1.1 % higher at 700 nm than the constant value (0.543) and should be taken into account when calculating the water leaving radiance and normalized water leaving radiance from in-water measurements.
透射系数，通常用于将紧挨着海洋表面下方的向上天底辐射传播到海面上方，在海水中一直被假定为0.543这个恒定值。由于海水的折射率随波长、盐度和温度而变化，应考虑透射系数随这些参数的变化，特别是如果对于使用该系数得出的量需要低不确定性时。尤其这个系数的波长依赖性很重要。例如，在盐度为35 g/kg和温度为26°C时，在380 nm处透射系数将比恒定值（0.543）低1.3%，在700 nm处高1.1%，并且在根据水中测量值计算离水辐射率和归一化离水辐射率时应予以考虑。
