Application of a regression algorithm to the problem of studying horizontal inhomogeneity of the cloud liquid water path on the basis of the ground-based microwave observations in the angular scanning mode
The results of the cloud liquid water path (LWP) “land-sea” gradient retrieval from ground-based measurements of downwelling microwave radiation near the coastline of the Gulf of Finland in Saint-Petersburg region are presented. The measurements were carried out with the RPG-HATPRO radiometer operating at the Faculty of Physics of Saint-Petersburg State University in the angular scanning mode. The inverse problem was solved by the linear regression method. Different statistical models of cloud cover were used for training the algorithm. The LWP gradient mean values were derived over the winter and summer periods of seven years of observations. The results have shown positive “land-sea” LWP gradient (higher values over land and lower over sea) during both summer and winter seasons. This fact is qualitatively consistent with available satellite data.