ice caps

ice caps

(63A311) Suitability of Multispectral Imagers for Remote Sensing of Glacier Surfaces

3d ago
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Allen Pope & Gareth Rees As changes to mountain glaciers and ice caps continue to contribute significantly to many local water resources as well as global sea level rise, it is increasingly important to have a robust remote sensing method for measuring the annual mass balance of many glaciers in a region. Due to the insufficient accuracy of airborne or spaceborne altimeters, we focus on a technique using multispectral imagery with the sufficient spatial and temporal resolution to measure local and regional accumulation area ratios and/or equilibrium line altitudes. This unsupervised classification has been developed using two test glaciers (Langjökull, Iceland and Midtre Lovénbreen, Svalbard) and in situ surface reflectance measurements collected on both glaciers from a variety of surface types (e.g. ash-rich snow, fresh/drifted snow, melting snow, slush, wet ice, well-drained ice, etc.). Here we present work assessing the suitability of various multispectral sensors to classify surface facies of arctic glaciers and icecaps. Sensors addressed include the Landsat ETM+, Landsat Data Continuity Mission, MODIS, GMES Sentinel-2, and the Airborne Thematic Mapper; imagery continues to focus on the same test glaciers in Iceland and Svalbard. These sensors vary in many ways including spatial resolution (potential submeter up to 500 m), spectral bands, and repeat imaging time. Each of these factors has significant implications for the ability of the sensor to accurately delineate glacier surface facies. A more nuanced understanding of each sensor's strengths and weaknesses will better inform future regional and long-term monitoring of glacier mass balance.