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| Titel |
Earth system consequences of a Pine Island Glacier collapse |
| VerfasserIn |
Mattias Green, Andreas Schmittner |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250136420
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| Publikation (Nr.) |
 EGU/EGU2016-17457.pdf |
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| Zusammenfassung |
| An intermediate complexity climate model is used to simulate the impact of an accelerated
Pine Island Glacier mass loss on the large-scale ocean circulation and climate. Simulations
are performed for pre-industrial conditions using hosing levels consistent with present day
observation of 3,000 m3 s−1, at an accelerated rate of 6,000 m3 s−1, and at a total collapse
rate of 100,000 m3 s−1, and in all experiments the hosing lasted 100 years. It is shown that
even a modest input of meltwater from the glacier can introduce an initial cooling over the
upper part of the Southern Ocean due to increased stratification and ice cover leading to a
reduced upward heat flux from Circumpolar Deep Water. This causes global ocean heat
content to increase and global surface air temperatures to decrease. The Atlantic Meridional
Overturning Circulation (AMOC) increases, presumably due to changes in the
density difference between Antarctic Intermediate Water and North Atlantic Deep
Water. Simulations with a simultaneous hosing and increases of atmospheric CO2
concentrations show smaller effects of the hosing on global surface air temperature
and ocean heat content, which we attribute to the melting of Southern Ocean sea
ice. The sensitivity of the AMOC to the hosing is also reduced as the warming by
the atmosphere completely dominates the perturbations. Further consequences for
oceanic biogeochemical cycles in realistic future warming scenarios are discussed. |
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