Cryospheric and Polar Processes Seminar: Allen Pope

Multispectral classification of glaciers

-and-

Estimating supraglacial lake depth with Landsat 8

By Allen Pope, National Snow and Ice Data Center/CIRES

Part 1:

Multispectral remote sensing has been used for studying GIC and their changing characteristics for several decades. Glacier surfaces can be classified into a range of facies, or zones, which can be used as proxies for annual mass balance and also play a significant role in understanding glacier energy balance. However, multispectral sensors were not designed explicitly for snow and ice observation, so it is not self-evident that they should be optimal for remote sensing of glaciers. Therefore, this study approaches the problem from an inverse perspective. Starting with in situreflectance spectra from the full range of surfaces measured on two glaciers at the end of the melt season in order to capture the largest range of facies (Langjökull, Iceland and Midtre Lovénbreen, Svalbard), optimal satellites for glacier facies identification are investigated.

Part 2:

Supraglacial lakes play a significant role in glacial hydrological systems. To investigate these important processes, multispectral remote sensing provides multiple methods for estimating supraglacial lake depth. Landsat 8 is the newest satellite in the Landsat series. With new bands, higher dynamic range, and higher radiometric resolution, it has a lot of potential. This study uses in situ spectra and depth measurements to investigate the ability of Landsat 8 to estimate lake depths using multiple methods, as well as quantify improvements over Landsat 7's ETM+. Preliminary results are applied to a case study in Northwest Greenland using four images from summer 2013.