Journal metrics

Journal metrics

  • IF value: 3.174 IF 3.174
  • IF 5-year value: 3.841 IF 5-year 3.841
  • CiteScore value: 3.48 CiteScore 3.48
  • SNIP value: 1.078 SNIP 1.078
  • SJR value: 1.981 SJR 1.981
  • IPP value: 3.38 IPP 3.38
  • h5-index value: 42 h5-index 42
  • Scimago H index value: 58 Scimago H index 58
Discussion papers | Copyright
https://doi.org/10.5194/cp-2018-69
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 21 Jun 2018

Research article | 21 Jun 2018

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Climate of the Past (CP).

Deglacial evolution of regional Antarctic climate and Southern Ocean conditions in transient climate simulations

Daniel P. Lowry1, Nicholas R. Golledge1,2, Laurie Menviel3,4, and Nancy A. N. Bertler1,2 Daniel P. Lowry et al.
  • 1Antarctic Research Centre, Victoria University of Wellington, Wellington, 6012, New Zealand
  • 2GNS Science, Lower Hutt, 5010, New Zealand
  • 3Climate Change Research Centre and PANGEA Research Centre, University of New South Wales, New South Wales, 2052, Australia
  • 4ARC Centre of Excellence for Climate System Science, New South Wales, Sydney, Australia

Abstract. Constraining Antarctica′s climate evolution since the end of the Last Glacial Maximum (∼18kyr) remains a key challenge, but is important for accurately projecting future changes in Antarctic ice sheet mass balance. Here we perform spatial and temporal analysis of two transient deglacial climate simulations, one using a fully coupled GCM and one using an intermediate complexity model, to (1) better understand the mechanisms driving regional differences observed in paleoclimate records, and (2) identify the main strengths and limitations of the models in terms of parameters that impact ice sheet mass balance. The climate simulations show the greatest continental surface warming over the continental margins and regions with the greatest decrease in ice surface elevation, suggesting that sea ice-albedo feedbacks and ice sheet dynamics likely played strong roles in driving regional surface temperature differences during the deglaciation. The spatial distributions of simulated accumulation changes are quite distinct, with the intermediate complexity model experiencing resolution-related bias along the East Antarctic coast. Accumulation-temperature scaling relationships are fairly linear and constant further inland, but exhibit higher variability in the early to mid-Holocene over coastal regions. This climatic shift in the Holocene coincides with a weakening of the Amundsen Sea Low and a reduction in sea ice coverage. Circum-Antarctic coastal ocean temperatures at grounding line depths are highly sensitive to the meltwater forcings prescribed in each simulation, which are applied in different ways due to limited paleo-constraints. Although modelled centennial-scale rates of temperature and accumulation change are reasonable, clear model-proxy mismatches are observed with regard to the timing and duration of the Antarctic Cold Reversal (ACR) and Younger Dryas/early Holocene warming, suggesting that the Meltwater Pulse 1A and 1B events may be inadequately represented in these simulations. The incorporation of dynamic ice sheet models in future transient climate simulations could aid in improving meltwater forcing representation, and thus model-proxy agreement, through this time interval.

Download & links
Daniel P. Lowry et al.
Interactive discussion
Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for Authors/Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Daniel P. Lowry et al.
Daniel P. Lowry et al.
Viewed
Total article views: 494 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
393 87 14 494 25 9 9
  • HTML: 393
  • PDF: 87
  • XML: 14
  • Total: 494
  • Supplement: 25
  • BibTeX: 9
  • EndNote: 9
Views and downloads (calculated since 21 Jun 2018)
Cumulative views and downloads (calculated since 21 Jun 2018)
Viewed (geographical distribution)
Total article views: 494 (including HTML, PDF, and XML) Thereof 484 with geography defined and 10 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited
Saved
No saved metrics found.
Discussed
No discussed metrics found.
Latest update: 25 Sep 2018
Publications Copernicus
Download
Short summary
Using two climate models, we seek to better understand changes in Antarctic climate and Southern Ocean conditions during the last deglaciation. We highlight the importance of sea ice and ice topography changes on Antarctic surface temperatures and snow accumulation as well as the sensitivity of Southern Ocean temperatures to meltwater fluxes. These results demonstrate that climate model simulations of the deglaciation could be greatly improved by considering ice-ocean interactions and feedbacks.
Using two climate models, we seek to better understand changes in Antarctic climate and Southern...
Citation
Share