An Improved Combined Active and Passive Remote Sensing Approach for ICE Sheet Internal Temperature Profiling

Combined use of active and passive remote sensing can provide complementary information to simultaneously characterize the internal structure and internal physical properties of ice sheet. Well constraints of layering structure and density variation are the precondition to retrieve ice sheet internal temperature profile using radiometric measurements. This paper makes further improvement to the combined active and passive remote sensing approach presented in our previous preliminary study, mainly in density variation profile characterization, emission modeling, and density variation estimation method. In the combined approach, ice-penetrating radar-echo profile is used to estimate the ice sheet density variation, correcting the input density parameter for ice sheet emission model when interpretating the ice sheet emission observations. Validation of the improved combined approach is conducted with SMOS data and radar profiles collected by CReSIS around several ice core sites in Greenland. Evaluation of availability and advantage of the improved combined approach is performed based on the results.