The role of atmosphere-ocean-ice interactions in ice loss from Pine Island and Thwaites Glaciers, West Antarctica

大气-海洋-冰相互作用在西南极洲松岛和思韦茨冰川冰损失中的作用

• 批准号: NE/H02333X/1
• 负责人: John Turner
• 金额: $ 63.91万
• 依托单位: British Antarctic Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH02333X%2F1
• 关键词: role; atmosphere; ocean; ice; interactions

The West Antarctic Ice Sheet contains over 2 million cubic kilometres of ice, which if it all melting would raise sea level by over 3 metres. As part of the natural hydrological cycle of the ice sheet, ice flows down to the coast in a number of glaciers and is lost to the ocean as ice bergs. Snowfall across the Antarctic then replenishes the ice in the ice sheet. The two largest and fastest flowing West Antarctic outlet glaciers are the Pine Island Glacier and the Thwaites Glacier, which together drain about 10% of the West Antarctic ice sheet. In recent decades the Pine Island and Thwaites Glaciers have thinned and retreated at a remarkable rate, contributing nearly 10% of the observed rise in global sea level. Air temperatures on these glaciers are almost never above freezing, even during the summer months, so their retreat has not been a result of direct warming from the atmosphere. Instead, an increase of ocean temperature is thought to be responsible for the changes. The area of Pine Island Bay is susceptible to intrusions of relatively warm Circumpolar Deep Water that occurs across the floor of the continental shelves to the north of the region. It is known that the arrival of Circumpolar Deep Water to the area is affected by the weather systems over the ocean to the north of West Antarctica, and particularly to the depth and local of depressions. This research will shed light on why the Pine Island and Thwaites Glaciers have been retreating in recent decades and predict their evolution over the next century and produced improved predictions of their potential contribution to sea level rise. The links between weather patterns, ocean currents, melting under the glaciers and the retreat of the glaciers themselves are very complex and can only be understood by simulating them on computers. We will therefore develop new, detailed atmospheric, ocean and ice models to simulate the environment of the Southern Ocean north of the Pine Island bay. We have a great deal of meteorological data for the last 30 years and this will allow us to understand how changes in weather patterns have influenced the delivery of Circumpolar Deep Water to Pine Island Bay. We will therefore run our models for the period 1980 - 2010. However, satellite pictures of the area and information from the ocean floor of Pine Island bay collected by oceanographic equipment suggests that the glaciers have been retreating from at least the middle of the Twentieth Century. This could be a result of changes in the weather patterns during the last century, but in the remote Antarctic we have very few meteorological observations for this period. We will therefore reconstruct the weather patterns across this sector of the Southern Ocean during the Twentieth Century using the chemical signals locked into ice cores. The 21 nation International Trans Antarctic Scientific Expedition has collected many ice cores across West Antarctic and they will form the basis of our reconstruction. How the Pine Island Glacier and the Thwaites Glacier will change over the next century is an extremely important question because of the consequences for sea level rise. We will produce improved predictions of their change during the next century by using our knowledge of glacier retreat in terms of atmospheric circulation. We will use the predictions of atmospheric change across the ocean north of West Antarctica produced by the Intergovernmental Panel on Climate Change. Their predictions of atmospheric change for different increases of greenhouse gases will be used and will allow us to determine changes in Circumpolar Deep Water and therefore melt of the glaciers over the next century.

南极冰盖含有超过200万立方公里的冰，如果所有冰块都将融化将使海平面提高3米。作为冰盖自然水文循环的一部分，冰以许多冰川流向海岸，并随着冰雪的身份流向海洋。然后，南极的降雪将冰层中的冰层补充。两个最大，最快的南极露出冰川是松树岛冰川和Thwaites冰川，它们耗尽了约10％的南极冰盖。近几十年来，派恩岛（Pine Island）和Thwaites冰川（Thwaites Glaciers）以显着的速度变薄和退缩，占全球海平面上观察到的近10％。即使在夏季，这些冰川上的空气温度几乎永远不会超过冰点，因此它们的静修并不是导致大气中直接变暖的结果。相反，海洋温度的升高被认为是导致变化的原因。派恩岛湾（Pine Island Bay）的区域容易受到该地区北部大陆货架地板上相对温暖的圆形深水的侵入。众所周知，圆极深水到达该地区的到来受到南极西北部海洋的天气系统的影响，尤其是抑郁症的深度和局部。这项研究将阐明为什么Pine Island和Thwaites冰川在近几十年来一直在撤退，并预测其在下一世纪的演变，并改善了对它们对海平面上升的潜在贡献的预测。天气模式，洋流，冰川下融化和冰川本身的撤退之间的联系非常复杂，只能通过在计算机上模拟它们来理解它们。因此，我们将开发新的，详细的大气，海洋和冰模型，以模拟派恩岛湾以北的南大洋的环境。在过去的30年中，我们拥有大量的气象数据，这将使我们能够理解天气模式的变化如何影响到派恩岛湾的近极深水的传递。因此，我们将在1980年至2010年期间运行我们的模型。但是，海洋学设备收集的卫星图片和来自松岛海底的信息表明，冰川至少从20世纪中叶撤退了。这可能是由于上个世纪发生天气模式变化的结果，但是在偏远的南极，我们在此期间几乎没有气象学观察。因此，我们将使用锁定在冰芯中的化学信号来重建整个南大洋地区的天气模式。 21国国际跨国跨国科学探险队在南极西部收集了许多冰核，它们将构成我们重建的基础。派恩岛冰川和THWAITES冰川在下一世纪将如何变化是一个极为重要的问题，因为对海平面上升的后果。我们将通过使用我们对大气循环的冰川静修学知识来改善对下个世纪的变化的预测。我们将利用政府间气候变化面板生产的大气变化的预测。他们对大气变化的预测将使用大气变化，以确定圆极深水的变化，从而确定冰川的变化。

项目成果

Sources of uncertainty in projections of twenty-first century westerly wind changes over the Amundsen Sea, West Antarctica, in CMIP5 climate models

CMIP5 气候模型中南极洲西部阿蒙森海二十一世纪西风变化预测的不确定性来源

• DOI: 10.1007/s00382-013-2032-1
• 发表时间: 2014
• 期刊: Climate Dynamics
• 影响因子: 4.6
• 作者: Bracegirdle T

The Influence of the Amundsen-Bellingshausen Seas Low on the Climate of West Antarctica and Its Representation in Coupled Climate Model Simulations

• DOI: 10.1175/jcli-d-12-00813.1
• 发表时间: 2013-09-01
• 期刊: JOURNAL OF CLIMATE
• 影响因子: 4.9
• 作者: Hosking, J. Scott;Orr, Andrew;Phillips, Tony
• 通讯作者: Phillips, Tony

Geometric and oceanographic controls on melting beneath Pine Island Glacier

• DOI: 10.1002/2013jc009513
• 发表时间: 2014-04-01
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
• 影响因子: 3.6
• 作者: De Rydt, J.;Holland, P. R.;Jenkins, A.
• 通讯作者: Jenkins, A.

Retreat of Pine Island Glacier controlled by marine ice-sheet instability

• DOI: 10.1038/nclimate2094
• 发表时间: 2014-02-01
• 期刊: NATURE CLIMATE CHANGE
• 影响因子: 30.7
• 作者: Favier, L.;Durand, G.;Le Brocq, A. M.
• 通讯作者: Le Brocq, A. M.

Ice-shelf buttressing and the stability of marine ice sheets

• DOI: 10.5194/tc-7-647-2013
• 发表时间: 2013-01-01
• 期刊: CRYOSPHERE
• 影响因子: 5.2
• 作者: Gudmundsson, G. H.