Developments in Simulating and Parameterizing Interactions Between the Southern Ocean and the Antarctic Ice Sheet

2017 ◽  
Vol 3 (4) ◽  
pp. 316-329 ◽  
Author(s):  
Xylar S. Asay-Davis ◽  
Nicolas C. Jourdain ◽  
Yoshihiro Nakayama
Keyword(s):  
Southern Ocean ◽  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
The Antarctic

The Southern Ocean and its interaction with the Antarctic Ice Sheet

Science ◽  
2020 ◽  
Vol 367 (6484) ◽  
pp. 1326-1330
Author(s):  
David M. Holland ◽  
Keith W. Nicholls ◽  
Aurora Basinski
Keyword(s):  
Southern Ocean ◽  
Ocean Circulation ◽  
Thermal Structure ◽  
Ice Sheet ◽  
Major Influence ◽  
Antarctic Ice Sheet ◽  
Ice Shelves ◽  
Air Temperatures ◽  
The Antarctic ◽  
Circulation Changes

The Southern Ocean exerts a major influence on the mass balance of the Antarctic Ice Sheet, either indirectly, by its influence on air temperatures and winds, or directly, mostly through its effects on ice shelves. How much melting the ocean causes depends on the temperature of the water, which in turn is controlled by the combination of the thermal structure of the surrounding ocean and local ocean circulation, which in turn is determined largely by winds and bathymetry. As climate warms and atmospheric circulation changes, there will be follow-on changes in the ocean circulation and temperature. These consequences will affect the pace of mass loss of the Antarctic Ice Sheet.

scholarly journals Effect of meltwater input from the Antarctic ice sheet on the thermohaline circulation

1998 ◽  
Vol 27 ◽  
pp. 311-315 ◽  
Author(s):  
Uwf Mikolajewicz
Keyword(s):  
Southern Ocean ◽  
North Atlantic ◽  
General Circulation ◽  
Thermohaline Circulation ◽  
Ice Sheet ◽  
Circulation Model ◽  
Balance Model ◽  
Surface Cooling ◽  
Antarctic Ice Sheet ◽  
The Antarctic

The potential effect of meltwater input from the Antarctic ice sheet is studied in sensitivity experiments with an ocean general circulation model coupled to an energy-balance model of the atmosphere. The effect is generally a reduction of surface salinity and deep convection in The Southern Ocean, associated with surface cooling. There is an accompanying, delayed intensification of the overturning in the Northern Hemisphere, leading to warmer conditions over both the North Atlantic and North Pacific With a sufficiently large meltwater pulse it is possible to trigger switches between different steady states of the ocean's thermohaline circulation, which differ mainly in the formation rates of North Atlantic Deep Water. Thus a transient perturbation in the Southern Ocean can lead to long-term climate changes in both hemispheres. The model reacts morè sensitively to melt water input into theWeddell Sea than into the Ross Sea.

Impact of ice sheet – ocean interactions on the Southern Ocean using fully coupled models over a circumpolar domain

2021 ◽  
Author(s):  
Charles Pelletier ◽  
Lars Zipf ◽  
Konstanze Haubner ◽  
Deborah Verfaillie ◽  
Hugues Goosse ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Ice Sheet ◽  
The Arctic ◽  
Surface Cooling ◽  
Coupled Models ◽  
Sea Ice Extent ◽  
Antarctic Ice Sheet ◽  
Antarctic Sea Ice ◽  
The Antarctic

<p>From at least 1979 up until 2016, the surface of the Southern Ocean cooled down, leading to a small Antarctic sea ice extent increase, which is in stark contrast with the Arctic Ocean. The attribution of the origin of these robust observations is still very uncertain. Among other phenomena, the direct, two-way interactions between the Southern Ocean and the Antarctic ice sheet, through basal melting of its numerous and large ice-shelf cavities, have been suggested as a potentially important contributor of this cooling. In order to address this question, we perform multidecadal coupled ice sheet – ocean numerical simulations relying on f.ETISh-v1.7 and NEMO3.6-LIM3 for simulating the Antarctic ice sheet and Southern Ocean (including sea ice), respectively. This presentation is twofold. First, we present the technical aspects of the coupling infrastructure (e.g. workflow and exchanged information in between models). Second, we investigate the ice sheet – ocean feedbacks on the Southern Ocean, their interactions, and the roles of the related physical mechanisms on the ocean surface cooling.</p>

scholarly journals Modeling the breakup of tabular icebergs

2020 ◽  
Vol 6 (51) ◽  
pp. eabd1273
Author(s):  
Mark R. England ◽  
Till J. W. Wagner ◽  
Ian Eisenman
Keyword(s):  
Southern Ocean ◽  
Ice Sheet ◽  
Freshwater Flux ◽  
Antarctic Ice Sheet ◽  
State Estimate ◽  
Ice Shelves ◽  
The Antarctic

Nearly half of the freshwater flux from the Antarctic Ice Sheet into the Southern Ocean occurs in the form of large tabular icebergs that calve off the continent’s ice shelves. However, because of difficulties in adequately simulating their breakup, large Antarctic icebergs to date have either not been represented in models or represented but with no breakup scheme such that they consistently survive too long and travel too far compared with observations. Here, we introduce a representation of iceberg fracturing using a breakup scheme based on the “footloose mechanism.” We optimize the parameters of this breakup scheme by forcing the iceberg model with an ocean state estimate and comparing the modeled iceberg trajectories and areas with the Antarctic Iceberg Tracking Database. We show that including large icebergs and a representation of their breakup substantially affects the iceberg meltwater distribution, with implications for the circulation and stratification of the Southern Ocean.

scholarly journals A Joint Inversion Estimate of Antarctic Ice Sheet Mass Balance Using Multi-Geodetic Data Sets

2019 ◽  
Vol 11 (6) ◽  
pp. 653 ◽  
Author(s):  
Chunchun Gao ◽  
Yang Lu ◽  
Zizhan Zhang ◽  
Hongling Shi
Keyword(s):  
Mass Balance ◽  
Joint Inversion ◽  
Ice Sheet ◽  
Mass Change ◽  
West Antarctica ◽  
Amundsen Sea ◽  
Antarctic Ice Sheet ◽  
Forward Models ◽  
Uplift Rates ◽  
The Antarctic

Many recent mass balance estimates using the Gravity Recovery and Climate Experiment (GRACE) and satellite altimetry (including two kinds of sensors of radar and laser) show that the ice mass of the Antarctic ice sheet (AIS) is in overall decline. However, there are still large differences among previously published estimates of the total mass change, even in the same observed periods. The considerable error sources mainly arise from the forward models (e.g., glacial isostatic adjustment [GIA] and firn compaction) that may be uncertain but indispensable to simulate some processes not directly measured or obtained by these observations. To minimize the use of these forward models, we estimate the mass change of ice sheet and present-day GIA using multi-geodetic observations, including GRACE and Ice, Cloud and land Elevation Satellite (ICESat), as well as Global Positioning System (GPS), by an improved method of joint inversion estimate (JIE), which enables us to solve simultaneously for the Antarctic GIA and ice mass trends. The GIA uplift rates generated from our JIE method show a good agreement with the elastic-corrected GPS uplift rates, and the total GIA-induced mass change estimate for the AIS is 54 ± 27 Gt/yr, which is in line with many recent GPS calibrated GIA estimates. Our GIA result displays the presence of significant uplift rates in the Amundsen Sea Embayment of West Antarctica, where strong uplift has been observed by GPS. Over the period February 2003 to October 2009, the entire AIS changed in mass by −84 ± 31 Gt/yr (West Antarctica: −69 ± 24, East Antarctica: 12 ± 16 and the Antarctic Peninsula: −27 ± 8), greater than the GRACE-only estimates obtained from three Mascon solutions (CSR: −50 ± 30, JPL: −71 ± 30, and GSFC: −51 ± 33 Gt/yr) for the same period. This may imply that single GRACE data tend to underestimate ice mass loss due to the signal leakage and attenuation errors of ice discharge are often worse than that of surface mass balance over the AIS.

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