Preprints
https://doi.org/10.5194/esdd-3-801-2012
https://doi.org/10.5194/esdd-3-801-2012

  16 Aug 2012

16 Aug 2012

Review status: this preprint was under review for the journal ESD. A revision for further review has not been submitted.

Minor effect of meltwater on the ocean circulation during deglaciation

G. Lohmann1,2, K. Grosfeld1, M. Butzin1,2, P. Huybrechts3, and C. Zweck4 G. Lohmann et al.
  • 1Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
  • 2Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
  • 3Earth System Sciences & Departement Geografie, Vrije Universiteit Brussel, Brussel, Belgium
  • 4Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona, USA

Abstract. Decaying Northern Hemisphere ice sheets during deglaciation affect the high latitude hydrological balance in the North Atlantic and therefore the ocean circulation after the Last Glacial Maximum. Surprisingly, geological data suggest that meltwater fluxes of about 14–20 m sea-level equivalent flushed into the North Atlantic without significantly influencing the Atlantic meridional overturning circulation. Using a three-dimensional ocean circulation model coupled to an energy balance model of the atmosphere, we investigate the response of the ocean circulation to spatio-temporal variable deglacial freshwater discharges. Freshwater inputs are simulated by a three-dimensional thermo-mechanical ice sheet model of the Northern Hemisphere. In our experiments, we find a strong sensitivity of the ocean circulation when the deglacial meltwater is injected into the surface layers yielding a quasi shut-down. On the other hand, the parameterization of huge sub-glacial outbursts as so-called hyperpycnal flows are mimicked through bottom injections in ocean models leading to a reduced sensitivity of the overturning circulation against freshwater perturbations and providing a consistent representation of the deglacial climate evolution.

G. Lohmann et al.

 
Status: closed (peer review stopped)
Status: closed (peer review stopped)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed (peer review stopped)
Status: closed (peer review stopped)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

G. Lohmann et al.

G. Lohmann et al.

Viewed

Total article views: 1,249 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
679 467 103 1,249 78 93
  • HTML: 679
  • PDF: 467
  • XML: 103
  • Total: 1,249
  • BibTeX: 78
  • EndNote: 93
Views and downloads (calculated since 01 Feb 2013)
Cumulative views and downloads (calculated since 01 Feb 2013)

Cited

Saved

Latest update: 12 May 2021
Download
Altmetrics