The Potential for Estimating Snow Density Using SCATSAT-1 Scatterometer

Ku-band Scatterometers are best used for mapping snowmelt/freeze as normalized backscatter is sensitive to the water content of the snow. In this study, the potential of Ku-band scatterometer SCATSAT-1 at 13.515 GHz is explored with regard to the estimation of snow density, which is an important geophysical parameter of the snowpack behavior. The density calculation is done using horizontal-horizontal (HH) and vertical-vertical (VV) polarized data available at 2.25 km with incidence angles of 49° and 57° and snow dielectric constant inversion algorithm. The algorithm is tested over part of Indian Himalayas and Antarctica. Looyenga's semiempirical formula is used to estimate snow density in Antarctica, and a modified formula is used for the Himalayas. The validation of the analysis is done using reanalysis density data from European Centre for Medium Range Weather Forecasts (ECMWF) at Indian Himalayas during January 2017 and observed field density data during 2016-2017 at Antarctica. The correlation and mean absolute error between derived and modeled densities were 0.788 and 0.006 g/cm
³
for the Himalayas. A correlation of 0.81 and mean absolute error of 0.079 g/cm
³
at 10 cm depth was found out between observed and derived densities for Antarctica. The derived density varied with the temperature at a study site in Antarctica.