权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Assessing the sensitivity of major East Antarctic outlet glaciers to recent and future changes in the ocean-climate system

评估主要东南极出口冰川对海洋气候系统近期和未来变化的敏感性

基本信息

批准号：
NE/R000719/1
负责人：
Hilmar Gudmundsson
金额：
$ 38.74万
依托单位：
Northumbria University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FR000719%2F1
关键词：
Assessing sensitivity major East Antarctic

项目摘要

The Earth's atmosphere and oceans are warming as a result of increased concentrations of greenhouse gases. Glaciers melt when the Earth warms and water that was stored as ice on land runs off into the ocean and increases sea-level. Over the last few decades, measurements have shown that sea-level is increasing by around 3 millimetres per year, and that this is due to the expansion of the warmer ocean water and the runoff from glaciers. In the 20th century, the sea-level contribution from melting ice was dominated by small mountain glaciers and ice caps, but it is now known that the vast ice sheets in Greenland and Antarctica are contributing an equally large amount to sea level and that their contribution is accelerating. One of the main ways in which ice sheets contribute to sea-level (especially in Antarctica, but also in Greenland) is through rapidly-flowing outlet glaciers that transfer ice from the interior to the margins, where it breaks off as icebergs. Recent measurements, mostly using observations from satellites, have shown that many outlet glaciers are thinning and retreating and, in some cases, their flow is also accelerating. This helps explain why their ice discharge is increasing. These changes in outlet glaciers are complex, but scientists think that they are caused by warmer ocean temperatures and, in some cases, by the landscapes underneath the outlet glaciers, especially if they flow through deep valleys that are below sea level and get deeper inland under the ice. The most dramatic changes have been observed in Greenland and West Antarctica, which store around 6 and 4 m of sea-level equivalent, respectively. Thus, unlike smaller mountain glaciers, changes in outlet glaciers could contribute several metres to global sea-level, possibly over quite short time-scales (just a few centuries according to some predictions). It is for this reason that a lot of research is aimed at monitoring outlet glaciers in Greenland and West Antarctica. Most of the ice in Antarctica is, however, stored in East Antarctica, which holds a sea-level equivalent of around 53 m. It is perhaps surprising, therefore, that there are so few measurements of outlet glaciers in the East Antarctic Ice Sheet (EAIS), but this is probably because it was traditionally thought to be much more stable than West Antarctica. Recently, however, evidence has been uncovered which indicates that parts of the EAIS, especially those parts that that overlie deep valleys and basins, might have retreated quite dramatically when climate was slightly warmer in the past. Moreover, observations of just one or two glaciers in these same regions indicates that they are also thinning and retreating, similar to those in Greenland and West Antarctica. Thus, there is a small but growing body of evidence suggesting that some parts of the EAIS might also be vulnerable to global warming. Unfortunately, we do not have enough observations to know exactly what is happening in different parts of East Antarctica and there is a large amount of uncertainty about whether its outlet glaciers are sensitive to changes in the ocean and/or atmosphere. This project has been designed to specifically address this uncertainty. We will use satellite measurements to determine recent changes on some of the largest and most important outlet glaciers from different regions of East Antarctica. This will tell us where the most dramatic changes have taken place and which areas are more stable. We will then use a computer model to see what kind of changes would take place if air or ocean temperatures increase in the future. This will tell us which glaciers are most sensitive and what their contribution to sea level might be over the next few centuries. Even where glaciers are currently stable, it is important to know by how much climate would need to change before they might react. This new knowledge is vitally important to help governments plan for future changes in sea-level.

由于温室气体浓度的增加，地球的大气和海洋正在变暖。当地球变暖时，冰川融化，储存在陆地上的冰的水流入海洋，并提高海平面。在过去几十年中，测量表明，海平面每年上升约3毫米，这是由于海水变暖和冰川径流的扩大。在20世纪，冰川融化对海平面的贡献主要是小山冰川和冰帽，但现在人们知道，格陵兰和南极洲的巨大冰盖对海平面的贡献同样大，而且它们的贡献正在加速。冰盖影响海平面的主要方式之一(尤其是在南极洲，但在格陵兰岛也是如此)是通过快速流动的出口冰川，将冰从内陆转移到边缘，在那里它以冰山的形式断裂。最近的测量表明，许多出口冰川正在变薄和消退，在某些情况下，它们的流动也在加速。这有助于解释为什么它们的冰流量在增加。出口冰川的这些变化是复杂的，但科学家们认为，这些变化是由海洋温度上升造成的，在某些情况下，是由出口冰川下面的地形造成的，特别是如果它们流经低于海平面的深谷，并在冰下进入更深的内陆。格陵兰岛和南极洲西部的变化最为显著，它们分别储存了约6米和4米的海平面当量。因此，与较小的山地冰川不同，出口冰川的变化可能会在相当短的时间范围内(根据一些预测，只有几个世纪)对全球海平面造成几米的影响。正是出于这个原因，许多研究都旨在监测格陵兰岛和西南极的出口冰川。然而，南极洲的大部分冰都储存在东南极，那里的海平面相当于53米左右。因此，令人惊讶的是，关于东南极冰盖(EAIS)出口冰川的测量如此之少，但这可能是因为传统上认为它比南极洲西部更稳定。然而，最近发现的证据表明，当过去气候略有变暖时，EAIS的部分地区，特别是位于深谷和盆地之上的部分，可能已经相当戏剧性地后退了。此外，对这些地区的一两个冰川的观察表明，它们也在变薄和消退，类似于格陵兰岛和西南极的冰川。因此，有少量但不断增加的证据表明，EAIS的某些部分可能也容易受到全球变暖的影响。不幸的是，我们没有足够的观测来确切地了解东南极不同地区正在发生的事情，对于其出口冰川是否对海洋和/或大气的变化敏感也存在很大的不确定性。这个项目是专门为解决这一不确定性而设计的。我们将使用卫星测量来确定来自东南极洲不同地区的一些最大和最重要的出口冰川最近的变化。这将告诉我们哪里发生了最戏剧性的变化，哪些地区更稳定。然后我们将使用计算机模型来观察如果未来气温或海洋温度上升会发生什么样的变化。这将告诉我们哪些冰川是最敏感的，以及它们在未来几个世纪对海平面的贡献可能是什么。即使在冰川目前稳定的地方，了解气候需要变化多少才可能做出反应，这一点很重要。这一新知识对于帮助各国政府规划未来的海平面变化至关重要。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Increased warm water intrusions could cause mass loss in East Antarctica within 200 years

增加的暖水入侵可能会在200年内导致东南极洲的质量损失

DOI：
10.21203/rs.3.rs-1558927/v1
发表时间：
2022
期刊：
影响因子：
0
作者：
Jordan J
通讯作者：
Jordan J

The predictive power of ice sheet models and the regional sensitivity of ice loss to basal sliding parameterisations: A case study of Pine Island and Thwaites Glaciers, West Antarctica

冰盖模型的预测能力以及冰损失对基底滑动参数化的区域敏感性：以西南极洲松岛和思韦茨冰川为例

DOI：
10.5194/tc-2022-109
发表时间：
2022
期刊：
影响因子：
0
作者：
Barnes J
通讯作者：
Barnes J

Increased warm water intrusions could cause mass loss in East Antarctica during the next 200 years.

DOI：
10.1038/s41467-023-37553-2
发表时间：
2023-04-01
期刊：
NATURE COMMUNICATIONS
影响因子：
16.6
作者：
Jordan, James R.;Miles, B. W. J.;Gudmundsson, G. H.;Jamieson, S. S. R.;Jenkins, A.;Stokes, C. R.
通讯作者：
Stokes, C. R.

Supplementary material to "Slowdown of Shirase Glacier caused by strengthening alongshore winds"

“沿岸风增强导致白濑冰川速度减缓”的补充材料