What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris?

Rock debris on the surface of a glacier can dramatically reduce local melt rate, where primary factor governing reduction is layer thickness. Relating temperature to thickness recurring approach in literature, yet demonstrations reproducibility have been limited. Here, I present results field experiment conducted Canwell Glacier, Alaska, United States constrain how thermal data be used glaciology. These datasets include, 1) measured sub-daily “Østrem curve” time-series; 2) time-series high resolution images capturing several segments different thicknesses including measurements from 1); 3) profile through 38 cm cover; and 4) two Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) satellite acquired within 2 3 min field-based camera image. show that, while clear sky conditions are when space-borne sensors image glacier, this an unfavorable time, limiting likelihood that will unique signature. then propose empirical estimate compare it recently published methods. demonstrate instantaneous calibration essential previously methods, model parameters calibrated only 1 h prior repeat return diminished estimates, method proposed here remains robust time does not appear require re-calibration. uses at one location bare-ice sub-debris melt. Results comparable cumulative estimates requires explicit/external bare ice Finally, sub-pixel corrections ASTER imagery enable close resemblance resolution, imagery. offer deeper insight into what cannot tell us about properties