Ocean2Ice: Processes and variability of ocean heat transport toward ice shelves in the Amundsen Sea Embayment

Ocean2Ice：阿蒙森海湾冰架海洋热传输的过程和变化

• 批准号: NE/J005746/1
• 负责人: Adrian Jenkins
• 金额: $ 30.24万
• 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: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FJ005746%2F1
• 关键词: Ocean2Ice; Processes; variability; ocean; heat; Ocean2Ice; Processes; variability; ocean; heat

Imagine that the ocean is like a large gin and tonic. When you add ice to the drink, the level in the glass goes up. When the lump of ice melts, the level in the glass doesn't change, because the ice is floating. When ice that is currently resting on land in Antarctica goes into the sea, either as an iceberg or as meltwater, the sea level all over the world goes up. It used to be thought that the same amount of water went back to the Antarctic as snowfall, to compensate for the icebergs and meltwater, so the whole system was in balance. But some glaciers in the Antarctic (and Greenland) seem to be melting at a faster rate than they are being replaced. So the total amount of ice is getting smaller, because more of that water is in the ocean, adding to sea level rise. This is worrying, because we don't really know why this is happening, and if we can't understand why, it's difficult to predict whether future sea level will carry on increasing at a faster and faster rate, or whether it will slow down or go back to equilibrium. Governments planning sea level defences in low-lying areas for the next decades need to have a more certain prediction of likely levels. That means that the big computer models that they use to forecast future climates need to have even better and more complex physics than they do already.So, what can scientists do to find out why the ice is melting? When the glaciers finally reach the sea, they float on the seawater, as an ice shelf. One suggestion is that the ocean is providing more heat to melt the ice than it used to do. Even though the ocean isn't that warm in the Antarctic, it is a few degrees above freezing, and if it washes underneath the ice shelves it can give up a lot of heat. What we plan to do in this project is to go to one of the fastest melting glaciers, the Pine Island Glacier in the Amundsen Sea, Antarctica. This is one of the most remote parts of our planet - imagine going to the Pacific Ocean and then heading south until you meet Antarctica. We will put some instruments in the water near the ice shelf, to see how and why the warm ocean water gets close to the ice. Is it the wind that forces the water there? Is it waves going round the Antarctic continent? Does the water get channelled up troughs in the sea floor gouged by glaciers thousands of years ago?We plan to use some novel equipment in the Antarctic, such as gluing tiny sensors onto elephant seals' fur. The seals will remain in the area over winter, long after we've gone back home. Their sensors will send back information about the seals' habitat - for example the temperature and the saltiness. This is useful for us because we can't get observations in the wintertime any other way because the area is covered in sea ice. And it's good for the seals because it will help our biologist colleagues to better understand how vulnerable the elephant seals might be to climate change. We'll also put in the water a mechanical version of a seal, called a Seaglider. This goes up and down in the water making measurements as it goes, and much like the seal sensors, it will communicate when it's at the surface using mobile phone. While we're there with the ship, we'll make lots of measurements of the temperature and saltiness of the water, how fast it's going, and how mixed up it is. Looking at all these data sets together should give us a better understanding of how the heat is getting to the glacier.One of the important tools will be a variety of computer models. These will range from all-singing, all-dancing climate models, that try to include ice, ocean and atmosphere all interacting, to much simpler models that test our understanding of the physics at play. The final result of the work we plan to do should be better climate models to predict future sea levels.

想象一下海洋就像一个大杜松子酒和滋补品。当您在饮料中添加冰时，玻璃杯中的水平会上升。当冰块融化时，玻璃中的水平不会改变，因为冰是漂浮的。当目前正在南极洲土地上的冰作为冰山或融水时，世界各地的海平面就在上升。过去，人们认为，与降雪相同的水又回到了南极，以补偿冰山和熔融水，因此整个系统都处于平衡状态。但是南极（和格陵兰）中的某些冰川似乎比更换的速度更快地融化。因此，冰的总量越来越小，因为更多的水在海中，增加了海平面的上升。这令人担忧，因为我们真的不知道为什么会发生这种情况，如果我们不了解原因，很难预测未来的海平面是否会以越来越快的速度增加，或者它是否会减慢或回到平衡。在接下来的几十年中，计划在低洼地区计划海平面防御的政府需要对可能水平进行更确定的预测。这意味着他们用来预测未来气候的大型计算机模型需要比已经更好，更复杂的物理学。当冰川最终到达大海时，它们以冰架漂浮在海水上。一个建议是，海洋提供的热量比以往更多的热量融化冰。即使在南极的海洋不那么温暖，它也比冰点高几个度，如果它在冰架下面洗涤，它会放弃很多热量。我们打算在这个项目中做的是去南极洲阿蒙森海的派恩岛冰川最快的冰川之一。这是我们星球上最偏远的地区之一 - 想象一下去太平洋，然后向南行驶，直到与南极洲见面。我们将在冰架附近的水中放一些乐器，以了解温暖的海水如何以及为什么靠近冰。是迫使那里的水吗？它是在南极大陆绕的波浪吗？几千年前，水被冰川盖好的海底槽被引导吗？我们计划在南极使用一些新型设备，例如将微小的传感器粘在大象密封的皮毛上。我们回到家很久之后，海豹将在冬天留在该地区。他们的传感器将寄回有关密封栖息地的信息 - 例如温度和咸味。这对我们很有用，因为我们无法在冬季获得任何其他方式观察，因为该地区被海冰覆盖。这对密封件是有益的，因为它将帮助我们的生物学家同事更好地了解大象海豹可能对气候变化有多脆弱。我们还将在水中放入一个机械版本的密封件，称为Seaglider。这是在水上进行测量中上下的，就像密封传感器一样，它会在使用手机在地面时进行通信。当我们在船上时，我们将对水的温度和盐度，速度进行的速度以及混合方式进行大量测量。查看所有这些数据集应该使我们可以更好地了解热量如何进入冰川。其中一种重要的工具将是各种计算机模型。这些范围从试图包括冰，海洋和氛围在内的全烟，全舞气候模型，都是互动的，到更简单的模型，这些模型测试了我们对物理学的理解。我们计划做的工作的最终结果应该是预测未来海平面的更好的气候模型。