Effect of specular high-level clouds on scattered solar radiation fluxes at the zenith
I.D. Bryukhanov1,2, S.V. Zuev3, I.V. Samokhvalov1
1National Research Tomsk State University, Tomsk, Russia
2V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
3Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: high-level clouds, anomalous backscattering, oriented ice crystals, polarization lidar, backscattering phase matrix, zenith pyranometer, diffuse solar radiation
Abstract
The technique and results of a complex experiment on studying the effect of high-level clouds (HLCs) on the scattered solar radiation flux are described. The optical characteristics (scattering ratio, optical depth, and backscattering phase matrix) and geometric characteristics (the lower and upper boundary altitudes and vertical thickness) of clouds were estimated based on the lidar data, and the scattered solar radiation flux in the zenith direction was measured with a pyranometer. It is shown that specular HLCs, i.e., consisting of preferably horizontally oriented ice crystals, significantly reduce the fluxes of scattered solar radiation incident on the Earth’s surface in comparison with HLCs with approximately the same optical depth, but with chaotically orientated particles.
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