| 项目编号: | 1643174
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| 项目名称: | Collaborative Research: Modeling ice-ocean Interaction for the Rapidly Evolving Ice Shelf Cavities of Pine Island and Thwaites Glaciers, Antarctica |
| 作者: | Laurence Padman
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| 承担单位: | Earth and Space Research
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| 批准年: | 2017
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| 开始日期: | 2017-07-15
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| 结束日期: | 2020-06-30
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| 资助金额: | 272074
|
| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Polar
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| 英文关键词: | ice loss
; ice shelf
; ice
; rate
; ice-sheet
; thwaites glacier
; pine island
; melting
; west antarctica
; ice-flow
; ocean-circulation
; ice-flow model
; future fully-coupled ice-sheet/ocean model
; west antarctic ice sheet
; cavity circulation
; uncertainty
; ice-shelf cavity
; nearby continental shelf
; high-resolution ice-shelf-cavity circulation model
; ice sheet
; several semi-coupled ice-ocean simulation
; ice-sheet response
; ice-sheet volume
|
| 英文摘要: | The West Antarctic Ice Sheet contains enough ice to raise global sea levels by 3-4 meters. Ice-sheet volume falls, and sea level increases, when more ice is lost to the ocean by glacier flow than is replaced by snowfall. Glacier speed is reduced when ice shelves, which are the floating extensions of the ice sheets, are present. Processes that affect ice shelf thickness and extent therefore influence the rates of grounded ice loss and sea-level rise. West Antarctica is currently losing ice, at an accelerating rate, with most loss occurring in the Amundsen Sea region via discharge from Pine Island and Thwaites glaciers. This loss was initiated by increased circulation of relatively warm ocean water beneath these glacier's ice shelves, causing them to thin by melting. However, this melting also depends on how the changing shape of the ice shelves affects the ocean circulation beneath them and the speeds of the grounded glaciers upstream. Limited understanding of these processes leads to uncertainties in estimates of future ice loss. This interdisciplinary project brings together glaciologists and oceanographers from three US institutions to study the interactions between changing glacier flow, ice shelf shape and extent, and ocean circulation. Data and numerical models will be used to identify the key processes that determine how rapidly this region can shed ice. The project team will train postdocs and graduate students in cutting-edge modeling techniques, and educate the public about Antarctic ice loss through talks, school science fairs, and Seattle Science Center's annual Polar Science Weekend.
The project team will conduct simulations, using a combination of ice-sheet and ocean models, to reduce uncertainties in projected ice loss from Pine Island and Thwaites glaciers by: (i) assessing how ice-shelf melt rates will change as the ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of sub-shelf melt rates to changes in ocean state on the nearby continental shelf. These studies will reduce uncertainty on ice loss and sea-level rise estimates, and lay the groundwork for development of future fully-coupled ice-sheet/ocean models. The project will first develop high-resolution ice-shelf-cavity circulation models driven by modern observed regional ocean state and validated with estimates of melt derived from satellite observations. Next, an ice-flow model will be used to estimate the future grounding retreat. An iterative process with the ocean-circulation and ice-flow models will then simulate melt rates at each stage of retreat. These results will help assess the validity of the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway, which was based on simplified models of melt rate. These models will also provide a better understanding of the sensitivity of melt to regional forcing such as changes in Circumpolar Deep Water temperature and wind-driven changes in thermocline height. Finally, several semi-coupled ice-ocean simulations will help determine the influence of the ocean-circulation driven melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/89705
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Laurence Padman. Collaborative Research: Modeling ice-ocean Interaction for the Rapidly Evolving Ice Shelf Cavities of Pine Island and Thwaites Glaciers, Antarctica. 2017-01-01.
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