Mass gains of the Antarctic ice sheet exceed losses
Open Access
- 1 January 2015
- journal article
- Published by International Glaciological Society in Journal of Glaciology
- Vol. 61 (230), 1019-1036
- https://doi.org/10.3189/2015jog15j071
Abstract
Mass changes of the Antarctic ice sheet impact sea-level rise as climate changes, but recent rates have been uncertain. Ice, Cloud and land Elevation Satellite (ICESat) data (2003–08) show mass gains from snow accumulation exceeded discharge losses by 82 ± 25 Gt a−1, reducing global sea-level rise by 0.23 mm a−1. European Remote-sensing Satellite (ERS) data (1992–2001) give a similar gain of 112 61 Gt a−1. Gains of 136 Gt a−1 in East Antarctica (EA) and 72 Gt a−1 in four drainage systems (WA2) in West Antarctic (WA) exceed losses of 97 Gt a−1 from three coastal drainage systems (WA1) and 29 Gt a−1 from the Antarctic Peninsula (AP). EA dynamic thickening of 147 Gt a−1 is a continuing response to increased accumulation (>50%) since the early Holocene. Recent accumulation loss of 11 Gt a−1 in EA indicates thickening is not from contemporaneous snowfall increases. Similarly, the WA2 gain is mainly (60 Gt a−1) dynamic thickening. In WA1 and the AP, increased losses of 66 ± 16 Gt a−1 from increased dynamic thinning from accelerating glaciers are 50% offset by greater WA snowfall. The decadal increase in dynamic thinning in WA1 and the AP is approximately one-third of the long-term dynamic thickening in EA and WA2, which should buffer additional dynamic thinning for decades.This publication has 60 references indexed in Scilit:
- A range correction for ICESat and its potential impact on ice-sheet mass balance studiesThe Cryosphere, 2014
- Antarctic contribution to sea level rise observed by GRACE with improved GIA correctionJournal of Geophysical Research: Solid Earth, 2013
- A new glacial isostatic adjustment model for Antarctica: calibrated and tested using observations of relative sea-level change and present-day uplift ratesGeophysical Journal International, 2012
- Overview and Assessment of Antarctic Ice-Sheet Mass Balance Estimates: 1992–2009Surveys in Geophysics, 2011
- The ERA‐Interim reanalysis: configuration and performance of the data assimilation systemQuarterly Journal of the Royal Meteorological Society, 2011
- Five years of Arctic sea ice freeboard measurements from the Ice, Cloud and land Elevation SatelliteJournal of Geophysical Research: Oceans, 2009
- Elevation Changes in Antarctica Mainly Determined by Accumulation VariabilityScience, 2008
- Observational evidence on the stability of the hydro‐glaciological regime of subglacial Lake VostokGeophysical Research Letters, 2008
- ICESat sea level comparisonsGeophysical Research Letters, 2005
- Changes in west Antarctic ice stream velocities: Observation and analysisJournal of Geophysical Research, 2002