Toward Internal Ice-Sheet Temperature Retrieval Using Microwave Radiometry and Simplified Ice-Flow Models

Ice sheets are fundamental components of the Earth’s system that impact the climate through their contribution to global sea level. Knowledge of an ice sheet’s internal temperature is essential to improve understanding of its dynamics and hence its mass balance. We present an over-complete set – termed a dictionary of functions– for approximating the ISSM-simulated vertical temperature profiles obtained over the Greenland continent. Next, we present an algorithm to retrieve the internal ice-sheet temperature from brightness temperature measurements obtained. Finally, we compare the root mean square error (RMSE) between the recovered temperature profile using the Robin model, extended Robin model and Dictionary based method and the true temperature profile by varying the radiometric noise in the brightness temperature. We quantitatively establish that the proposed dictionary based method outperforms the Robin model in recovering the ice-sheet temperature profile from radiometic measurements.