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| Titel |
Ice dynamic contribution to sea-level rise from the Antarctic Peninsula over the next 300 years |
| VerfasserIn |
Clemens Schannwell, Nicholas Barrand, Richard Hindmarsh, Valentina Radic |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250107788
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| Publikation (Nr.) |
 EGU/EGU2015-10240.pdf |
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| Zusammenfassung |
| Ice shelves fringing the Antarctic Peninsula (AP) ice sheet have collapsed or retreated in
response to rapid regional climate warming. This removal of ice shelves has led
to speed-up and subsequent dynamic thinning of outlet glaciers, contributing to
sea-level rise (SLR). The British Antarctic Survey Antarctic Peninsula Ice Sheet
Model (BAS-APISM) was used to simulate the grounded ice sheet response to
future ice shelf collapse over the next 300 years. BAS-APISM solves the linearized
shallow ice approximation, permitting low computational cost and a large ensemble of
scenario calculations. To simulate the ice-dynamic SLR contribution from the AP,
the timing of future ice shelf collapse events are estimated by tracking thermal
limits of ice shelf viability (-5°C and -9°C mean annual isotherm) in IPCC global
climate model (GCM) ensemble temperature projections. If the ice shelf collapses, a
grounding-line retreat is applied to each drainage basin feeding into the ice shelf.
Temperature fields from 14 different GCMs with two emission scenarios (RCP4.5
and RCP8.5) are used. Grounding-line retreat scenarios at individual outlet glacier
drainage basins are derived using a new parameterization based on multivariate linear
regression. A total of 210 ice shelf nourishing basins are modelled. Owing to the
linearized ice sheet model, each drainage basin can be modelled individually and SLR
contributions from each drainage basin are then simply summed over all basins. Each
individual ice shelf nourishing drainage basin was simulated using the ice shelf
collapse timing of 14 GCMs with two emission scenarios and tracking the pair of ice
shelf viability limits in each GCM. This amounts to ~22000 simulations for all
210 ice shelf nourishing drainage basins. Simulations throughout the GCM and
emission ensembles result in SLR of between ~2 and ~17 mm, depending on the
timing and collapse state of individual ice shelves. The results highlight the critical
role of George VI Ice Shelf in regulation of future SLR from the AP ice sheet. |
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