Antarctic iceberg impacts on future Southern Hemisphere climate

Fabian Schloesser, Tobias Friedrich, Axel Timmermann, Robert M. DeConto, David Pollard

Research output: Contribution to journalLetter

Abstract

Future iceberg and meltwater discharge from the Antarctic ice sheet (AIS) could substantially exceed present levels, with strong implications for future climate and sea levels. Recent climate model simulations on the impact of a rapid disintegration of the AIS on climate have applied idealized freshwater forcing scenarios1,2 rather than the more realistic iceberg forcing. Here we use a coupled climate–iceberg model to determine the climatic effects of combined iceberg latent heat of fusion and freshwater forcing. The iceberg forcing is derived from an ensemble of future simulations conducted using the Penn State ice-sheet model3. In agreement with previous studies, the simulated AIS meltwater forcing causes a substantial delay in greenhouse warming in the Southern Hemisphere and activates a transient positive feedback between surface freshening, subsurface warming and ice-sheet/shelf melting, which can last for about 100 years and may contribute to an accelerated ice loss around Antarctica. However, accounting further for the oceanic heat loss due to iceberg melting considerably increases the surface cooling effect and reduces the subsurface temperature feedback amplitude. Our findings document the importance of considering realistic climate–ice sheet–iceberg coupling for future climate and sea-level projections.

Original languageEnglish (US)
Pages (from-to)672-677
Number of pages6
JournalNature Climate Change
Volume9
Issue number9
DOIs
StatePublished - Sep 1 2019

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iceberg
Southern Hemisphere
ice sheet
climate
heat
meltwater
warming
melting
Antarctica
sea level
simulation model
projection
simulation
climate modeling
cause
present
cooling
ice
temperature
loss

All Science Journal Classification (ASJC) codes

  • Environmental Science (miscellaneous)
  • Social Sciences (miscellaneous)

Cite this

Schloesser, Fabian ; Friedrich, Tobias ; Timmermann, Axel ; DeConto, Robert M. ; Pollard, David. / Antarctic iceberg impacts on future Southern Hemisphere climate. In: Nature Climate Change. 2019 ; Vol. 9, No. 9. pp. 672-677.
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title = "Antarctic iceberg impacts on future Southern Hemisphere climate",
abstract = "Future iceberg and meltwater discharge from the Antarctic ice sheet (AIS) could substantially exceed present levels, with strong implications for future climate and sea levels. Recent climate model simulations on the impact of a rapid disintegration of the AIS on climate have applied idealized freshwater forcing scenarios1,2 rather than the more realistic iceberg forcing. Here we use a coupled climate–iceberg model to determine the climatic effects of combined iceberg latent heat of fusion and freshwater forcing. The iceberg forcing is derived from an ensemble of future simulations conducted using the Penn State ice-sheet model3. In agreement with previous studies, the simulated AIS meltwater forcing causes a substantial delay in greenhouse warming in the Southern Hemisphere and activates a transient positive feedback between surface freshening, subsurface warming and ice-sheet/shelf melting, which can last for about 100 years and may contribute to an accelerated ice loss around Antarctica. However, accounting further for the oceanic heat loss due to iceberg melting considerably increases the surface cooling effect and reduces the subsurface temperature feedback amplitude. Our findings document the importance of considering realistic climate–ice sheet–iceberg coupling for future climate and sea-level projections.",
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Schloesser, F, Friedrich, T, Timmermann, A, DeConto, RM & Pollard, D 2019, 'Antarctic iceberg impacts on future Southern Hemisphere climate', Nature Climate Change, vol. 9, no. 9, pp. 672-677. https://doi.org/10.1038/s41558-019-0546-1

Antarctic iceberg impacts on future Southern Hemisphere climate. / Schloesser, Fabian; Friedrich, Tobias; Timmermann, Axel; DeConto, Robert M.; Pollard, David.

In: Nature Climate Change, Vol. 9, No. 9, 01.09.2019, p. 672-677.

Research output: Contribution to journalLetter

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