Articles | Volume 10, issue 4
The Cryosphere, 10, 1707–1719, 2016
The Cryosphere, 10, 1707–1719, 2016

Research article 10 Aug 2016

Research article | 10 Aug 2016

MABEL photon-counting laser altimetry data in Alaska for ICESat-2 simulations and development

Kelly M. Brunt1,2, Thomas A. Neumann2, Jason M. Amundson3, Jeffrey L. Kavanaugh4, Mahsa S. Moussavi5,6, Kaitlin M. Walsh2,7, William B. Cook2, and Thorsten Markus2 Kelly M. Brunt et al.
  • 1Earth System Science Interdisciplinary Center (ESSIC), University of Maryland, College Park, MD, USA
  • 2NASA Goddard Space Flight Center, Greenbelt, MD, USA
  • 3Department of Natural Sciences, University of Alaska Southeast, Juneau, AK, USA
  • 4Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, Canada
  • 5Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO, USA
  • 6National Snow and Ice Data Center (NSIDC), CIRES, University of Colorado, Boulder, CO, USA
  • 7Stinger Ghaffarian Technologies, Inc., Greenbelt, MD, USA

Abstract. Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is scheduled to launch in late 2017 and will carry the Advanced Topographic Laser Altimeter System (ATLAS), which is a photon-counting laser altimeter and represents a new approach to satellite determination of surface elevation. Given the new technology of ATLAS, an airborne instrument, the Multiple Altimeter Beam Experimental Lidar (MABEL), was developed to provide data needed for satellite-algorithm development and ICESat-2 error analysis. MABEL was deployed out of Fairbanks, Alaska, in July 2014 to provide a test dataset for algorithm development in summer conditions with water-saturated snow and ice surfaces. Here we compare MABEL lidar data to in situ observations in Southeast Alaska to assess instrument performance in summer conditions and in the presence of glacier surface melt ponds and a wet snowpack. Results indicate the following: (1) based on MABEL and in situ data comparisons, the ATLAS 90 m beam-spacing strategy will provide a valid assessment of across-track slope that is consistent with shallow slopes (< 1°) of an ice-sheet interior over 50 to 150 m length scales; (2) the dense along-track sampling strategy of photon counting systems can provide crevasse detail; and (3) MABEL 532 nm wavelength light may sample both the surface and subsurface of shallow (approximately 2 m deep) supraglacial melt ponds. The data associated with crevasses and melt ponds indicate the potential ICESat-2 will have for the study of mountain and other small glaciers.

Short summary
This paper highlights results from a 2014 airborne laser altimetry campaign over Alaskan glaciers. The study was conducted in support of a NASA satellite mission (ICESat-2, scheduled to launch in 2017). The study indicates that the planned beam configuration for ICESat-2 is ideal for determining local slope, which is critical for the determination of ice-sheet elevation change. Results also suggest that ICESat-2 will contribute significantly to glacier studies in the mid-latitudes.