Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 7, 1901-1914, 2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
17 Dec 2013
Constraining GRACE-derived cryosphere-attributed signal to irregularly shaped ice-covered areas
W. Colgan1,2, S. Luthcke3, W. Abdalati1, and M. Citterio2 1Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
2Geological Survey of Denmark and Greenland, Copenhagen, Denmark
3Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD, USA
Abstract. We use a Monte Carlo approach to invert a spherical harmonic representation of cryosphere-attributed mass change in order to infer the most likely underlying mass changes within irregularly shaped ice-covered areas at nominal 26 km resolution. By inverting a spherical harmonic representation through the incorporation of additional fractional ice coverage information, this approach seeks to eliminate signal leakage between non-ice-covered and ice-covered areas. The spherical harmonic representation suggests a Greenland mass loss of 251 ± 25 Gt a−1 over the December 2003 to December 2010 period. The inversion suggests 218 ± 20 Gt a−1 was due to the ice sheet proper, and 34 ± 5 Gt a−1 (or ~14%) was due to Greenland peripheral glaciers and ice caps (GrPGICs). This mass loss from GrPGICs exceeds that inferred from all ice masses on both Ellesmere and Devon islands combined. This partition therefore highlights that GRACE-derived "Greenland" mass loss cannot be taken as synonymous with "Greenland ice sheet" mass loss when making comparisons with estimates of ice sheet mass balance derived from techniques that sample only the ice sheet proper.

Citation: Colgan, W., Luthcke, S., Abdalati, W., and Citterio, M.: Constraining GRACE-derived cryosphere-attributed signal to irregularly shaped ice-covered areas, The Cryosphere, 7, 1901-1914,, 2013.
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