Modeling South Pacific Ice-Ocean Interactions in the Global Climate System
The objective of this project has been to improve the modeling of interactions between large Antarctic ice shelves and adjacent regions of the Southern Ocean. Our larger goal is to gain a better understanding of the extent to which the ocean controls ice shelf attrition, thereby influencing the size...
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ftnasantrs:oai:casi.ntrs.nasa.gov:20020004188 2023-05-15T13:30:43+02:00 Modeling South Pacific Ice-Ocean Interactions in the Global Climate System Holland, David M. Jenkins, Adrian Jacobs, Stanley S. Unclassified, Unlimited, Publicly available [2001] application/pdf http://hdl.handle.net/2060/20020004188 unknown Document ID: 20020004188 http://hdl.handle.net/2060/20020004188 No Copyright CASI Environment Pollution 2001 ftnasantrs 2019-07-21T02:42:25Z The objective of this project has been to improve the modeling of interactions between large Antarctic ice shelves and adjacent regions of the Southern Ocean. Our larger goal is to gain a better understanding of the extent to which the ocean controls ice shelf attrition, thereby influencing the size and dynamics of the Antarctic Ice Sheet. Melting and freezing under ice shelves also impacts seawater properties, regional upwelling and sinking and the larger-scale ocean circulation. Modifying an isopycnal coordinate general circulation model for use in sub-ice shelf cavities, we found that the abrupt change in water column thickness at an ice shelf front does not form a strong barrier to buoyancy-driven circulation across the front. Outflow along the ice shelf base, driven by melting of the thickest ice, is balanced by deep inflow. Substantial effort was focused on the Filchner-Ronne cavity, where other models have been applied and time-series records are available from instruments suspended beneath the ice. A model comparison indicated that observed changes in the production of High Salinity Shelf Water could have a major impact on circulation within the cavity. This water propagates into the cavity with an asymmetric seasonal signal that has similar phasing and shape in the model and observations, and can be related to winter production at the sea surface. Even remote parts of the sub-ice shelf cavity are impacted by external forcing on sub-annual time scales. This shows that cavity circulations and products, and therefore cavity shape, will respond to interannual variability in sea ice production and longer-term climate change. The isopycnal model gives generally lower net melt rates than have been obtained from other models and oceanographic data, perhaps due to its boundary layer formulation, or the lack of tidal forcing. Work continues on a manuscript describing the Ross cavity results. Other/Unknown Material Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Sea ice Southern Ocean NASA Technical Reports Server (NTRS) Antarctic Pacific Southern Ocean The Antarctic |
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NASA Technical Reports Server (NTRS) |
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ftnasantrs |
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topic |
Environment Pollution |
spellingShingle |
Environment Pollution Holland, David M. Jenkins, Adrian Jacobs, Stanley S. Modeling South Pacific Ice-Ocean Interactions in the Global Climate System |
topic_facet |
Environment Pollution |
description |
The objective of this project has been to improve the modeling of interactions between large Antarctic ice shelves and adjacent regions of the Southern Ocean. Our larger goal is to gain a better understanding of the extent to which the ocean controls ice shelf attrition, thereby influencing the size and dynamics of the Antarctic Ice Sheet. Melting and freezing under ice shelves also impacts seawater properties, regional upwelling and sinking and the larger-scale ocean circulation. Modifying an isopycnal coordinate general circulation model for use in sub-ice shelf cavities, we found that the abrupt change in water column thickness at an ice shelf front does not form a strong barrier to buoyancy-driven circulation across the front. Outflow along the ice shelf base, driven by melting of the thickest ice, is balanced by deep inflow. Substantial effort was focused on the Filchner-Ronne cavity, where other models have been applied and time-series records are available from instruments suspended beneath the ice. A model comparison indicated that observed changes in the production of High Salinity Shelf Water could have a major impact on circulation within the cavity. This water propagates into the cavity with an asymmetric seasonal signal that has similar phasing and shape in the model and observations, and can be related to winter production at the sea surface. Even remote parts of the sub-ice shelf cavity are impacted by external forcing on sub-annual time scales. This shows that cavity circulations and products, and therefore cavity shape, will respond to interannual variability in sea ice production and longer-term climate change. The isopycnal model gives generally lower net melt rates than have been obtained from other models and oceanographic data, perhaps due to its boundary layer formulation, or the lack of tidal forcing. Work continues on a manuscript describing the Ross cavity results. |
author |
Holland, David M. Jenkins, Adrian Jacobs, Stanley S. |
author_facet |
Holland, David M. Jenkins, Adrian Jacobs, Stanley S. |
author_sort |
Holland, David M. |
title |
Modeling South Pacific Ice-Ocean Interactions in the Global Climate System |
title_short |
Modeling South Pacific Ice-Ocean Interactions in the Global Climate System |
title_full |
Modeling South Pacific Ice-Ocean Interactions in the Global Climate System |
title_fullStr |
Modeling South Pacific Ice-Ocean Interactions in the Global Climate System |
title_full_unstemmed |
Modeling South Pacific Ice-Ocean Interactions in the Global Climate System |
title_sort |
modeling south pacific ice-ocean interactions in the global climate system |
publishDate |
2001 |
url |
http://hdl.handle.net/2060/20020004188 |
op_coverage |
Unclassified, Unlimited, Publicly available |
geographic |
Antarctic Pacific Southern Ocean The Antarctic |
geographic_facet |
Antarctic Pacific Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf Ice Shelves Sea ice Southern Ocean |
op_source |
CASI |
op_relation |
Document ID: 20020004188 http://hdl.handle.net/2060/20020004188 |
op_rights |
No Copyright |
_version_ |
1766011634237571072 |