Hybrid inventory, gravimetry and altimetry (HIGA) mass balance product for Greenland and the Canadian Arctic
W. Colgan1,2, W. Abdalati2, M. Citterio1, B. Csatho3, X. Fettweis4, S. Luthcke5, G. Moholdt6, and M. Stober71Marine Geology and Glaciology, Geological Survey of Denmark and Greenland, Copenhagen, Denmark 2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA 3Department of Geology, State University of New York, Buffalo, NY, USA 4Department of Geography, University of Liége, Liége, Belgium 5Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD, USA 6Scripps Institution of Oceanography, University of California, San Diego, CA, USA 7Stuttgart University of Applied Sciences, Stuttgart, Germany
Received: 03 Jan 2014 – Accepted for review: 08 Jan 2014 – Discussion started: 23 Jan 2014
Abstract. We present a novel inversion algorithm that generates a mass balance field that is simultaneously consistent with independent observations of glacier inventory derived from optical imagery, cryosphere-attributed mass changes derived from satellite gravimetry, and ice surface elevation changes derived from airborne and satellite altimetry. We use this algorithm to assess mass balance across Greenland and the Canadian Arctic over the December 2003 to December 2010 period at 26 km resolution. We assess a total mass loss of 316 ± 37 Gt a−1 over Greenland and the Canadian Arctic, with 217 ± 20 Gt a−1 being attributed to the Greenland Ice Sheet proper, and 38 ± 6 Gt a−1 and 50 ± 8 Gt a−1 being attributed to peripheral glaciers in Greenland and the Canadian Arctic, respectively. These absolute values are dependent on the gravimetry-derived spherical harmonic representation we invert. Our attempt to validate local values of algorithm-inferred mass balance reveals a paucity of in situ observations. At four sites, where direct comparison between algorithm-inferred and in situ mass balance is valid, we find an RMSD of 0.18 m WE a−1. Differencing algorithm-inferred mass balance with previously modelled surface mass balance, in order to solve the ice dynamic portion of mass balance as a residual, allows the transient glacier continuity equation to be spatially partitioned across Greenland.
Colgan, W., Abdalati, W., Citterio, M., Csatho, B., Fettweis, X., Luthcke, S., Moholdt, G., and Stober, M.: Hybrid inventory, gravimetry and altimetry (HIGA) mass balance product for Greenland and the Canadian Arctic, The Cryosphere Discuss., 8, 537-580, doi:10.5194/tcd-8-537-2014, 2014.