Sea ice remote sensing using AMSR-E data: Surface roughness and refractive index

ea ice is a good indicator to monitor the global climate change. Many of previous studies using the satellite observations show a steady decline in Arctic sea ice. The study investigates the characteristics of the averaged surface roughness, and refractive index from March 2003 to July 2011 using the AMSR-E daily data. The surface roughness and refractive index of the sea ice is retrieved using a unique inversion algorithm based on the characteristics of the polarized reflectivities, the Hong approximation, and the incidence angles of the many current passive microwave satellite sensors. The averaged roughness and refractive index show the downward trend and opposite signature with an acceleration, respectively. From the seasonal variations, the averaged roughness and refractive index show the minimum and maximum values in the summer period, respectively. In addition, the annual peaks of two physical parameters exhibit the phase difference of a month. In conclusion, this research provides a physical explanation that the sea ice is melting increasingly using the satellite observation.