Constraining Grace-Derived Cryosphere-Attributed Signal to Irregularly Shaped Ice-Covered Areas

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...

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Bibliographic Details
Main Authors: Luthcke, S., Citterio, M., Abdalati, W., Colgan, W.
Format: Other/Unknown Material
Language:unknown
Published: 2013
Subjects:
Online Access:http://hdl.handle.net/2060/20150023402
Description
Summary: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 icecovered areas. The spherical harmonic representation suggests a Greenland mass loss of 251 plus or minus 25 Gt a(exp -1) over the December 2003 to December 2010 period. The inversion suggests 218 plus or minus 20 Gt a (exp -1) was due to the ice sheet proper, and 34 plus or minus 5 Gt a (exp -1) (or approximately 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.