Arctic Synoptic Basin-wide Oceanography.

北极综合盆地海洋学。

• 批准号: NE/D005965/1
• 负责人: Seymour Laxon
• 金额: $ 37.44万
• 依托单位: NATIONAL OCEANOGRAPHY CENTRE
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FD005965%2F1
• 关键词: Arctic; Synoptic; Basin; wide; Oceanography.

Look at a map of the world and find the Shetland Islands. Follow the 60 degrees north latitude circle eastwards. You pass through St. Petersburg, the Ural Mountains, Siberia, the Bering Sea, Alaska, northern Canada, the southern tip of Greenland, then back to the Shetlands. All these places are cold, harsh environments, particularly in winter, except the Shetlands, which is wet and windy but quite mild all year. This is because in the UK we benefit from heat brought northwards by the Atlantic Ocean in a current called the Conveyor Belt. This current is driven by surface water being made to sink by the extreme cold in and around the Arctic. It returns southwards through the Atlantic at great depths. Scientists think it is possible that the Conveyor Belt could slow down or stop, and if it did, the UK would get much colder. We know the planet has been warming for the last century or more, and we think this is due to the Greenhouse Effect. Burning fossil fuels puts a lot of carbon dioxide into the atmosphere, which stops heat from leaving the Earth, like the glass in a greenhouse. In a warming world, ice melts faster, and there is a lot of ice on the Earth: ice caps on Greenland and Antarctica, sea ice in the Arctic and Antarctic Oceans, glaciers in high mountains. This causes extra amounts of fresh water to flow into the oceans. Now this fresh water can affect the Conveyor Belt by acting like a lid of water too light to sink, so the Conveyor Belt stops. What is the chance of this happening? We do not know, because there is much we do not understand about how the Arctic Ocean works. You need a powerful icebreaker to get into the Arctic Ocean, and that's only really possible in the summer, because in winter the sea ice thickens and the weather is bad. Scientists all over the world agree that the Arctic Ocean is important because it contains a lot of freshwater, which is why, although it is difficult to make measurements in the Arctic, they have decided to join their efforts during the International Polar Year. Fresh water in the Arctic Ocean is either (nearly) pure fresh water in the form of sea ice, or as diluted sea water in the top 200 metres (roughly) of the ocean. The sea water in the Arctic is diluted because many large rivers flow into it. In Russia, the three largest are the Yenisei, the Lena and the Ob; in Alaska, the MacKenzie; and there are many smaller rivers. Fresh water arrives in the Arctic Ocean from other sources as well: more diluted sea water flows through the Bering Strait, between Russia and Alaska; in summer, ice caps melt a little and some of the melt water runs into the ocean; some of the sea ice melts straight into the ocean; and (of course) it snows. We plan to conduct a set of measurements around the Arctic Ocean, with help from many international partners. We want to know how much fresh water is in the Arctic Ocean now. We will use an ice breaker to enter the Arctic Ocean and will make measurements of water properties. We will also deploy instruments onto the ice cover that will provide data once we've gone and will analyse satellite imagery. All of this data will help us understand the current state of the Arctic Ocean and we will use mathematical models of the ocean, ice cover, and atmosphere to predict conditions before, during, and after the cruise. By measuring small quantities of chemicals dissolved in the ocean waters, we can work out where the ocean water came from. We want to know how this fresh water might travel from the Arctic Ocean southwards into the Atlantic. What route might it take? How does the ocean respond to the atmosphere, to river flows and to sea ice? We aim to answer these questions so that other scientists who try to forecast the Earth's climate in the coming years and decades will know how to represent the Arctic Ocean in their forecast models. And with good forecasts, we can plan for the future.

看一张世界地图，找出设得兰群岛。沿着北纬60度的圆圈向东走。你穿过圣彼得堡、乌拉尔山脉、西伯利亚、白令海、阿拉斯加、加拿大北部、格陵兰岛南端，然后回到设得兰群岛。所有这些地方都是寒冷、恶劣的环境，尤其是在冬天，除了设得兰群岛，那里潮湿多风，但全年都很温和。这是因为在英国，我们受益于大西洋向北带来的热量，这种热量被称为“传送带”。这种洋流是由北极及其周围的极端寒冷导致的地表水下沉所驱动的。它在大西洋深处向南返回。科学家们认为，“传送带”可能会减速或停止，如果是这样的话，英国将会变得更冷。我们知道地球在上个世纪或更长时间里一直在变暖，我们认为这是由于温室效应造成的。燃烧化石燃料会将大量二氧化碳排放到大气中，从而阻止热量离开地球，就像温室里的玻璃一样。在一个变暖的世界里，冰融化得更快，地球上有很多冰：格陵兰岛和南极洲的冰盖，北极和南极海洋的海冰，高山上的冰川。这导致额外的淡水流入海洋。现在，这些淡水可以影响传送带，就像一个盖子的水太轻，下沉，所以传送带停止。这种情况发生的几率有多大？我们不知道，因为我们对北冰洋的运作方式有很多不了解。你需要一艘强大的破冰船才能进入北冰洋，而这只有在夏天才有可能，因为在冬天，海冰会变厚，天气也很糟糕。全世界的科学家都认为北冰洋很重要，因为它含有大量的淡水，这就是为什么尽管很难在北极进行测量，但他们决定在国际极地年期间共同努力。北冰洋的淡水要么是（几乎）以海冰形式存在的纯净淡水，要么是海洋顶部200米（大约）被稀释的海水。北极的海水被稀释了，因为有许多大河流入。在俄罗斯，最大的三条河流是叶尼塞河、勒拿河和鄂河；阿拉斯加的麦肯齐河；还有许多小河。淡水也从其他来源进入北冰洋：更稀释的海水流经俄罗斯和阿拉斯加之间的白令海峡；在夏天，冰盖融化一点，一些融化的水流入海洋；一些海冰直接融进了海洋；（当然）下雪了。我们计划在许多国际合作伙伴的帮助下，在北冰洋周围进行一系列测量。我们想知道现在北冰洋有多少淡水。我们将利用破冰船进入北冰洋，对水的性质进行测量。我们还将在冰盖上部署仪器，一旦我们离开，这些仪器将提供数据，并将分析卫星图像。所有这些数据将帮助我们了解北冰洋的现状，我们将使用海洋、冰盖和大气的数学模型来预测航行之前、期间和之后的情况。通过测量溶解在海水中的少量化学物质，我们可以推算出海水的来源。我们想知道这些淡水是如何从北冰洋向南流入大西洋的。它可能走哪条路线？海洋是如何对大气、河流和海冰做出反应的？我们的目标是回答这些问题，以便其他试图预测未来几年和几十年地球气候的科学家知道如何在他们的预测模型中代表北冰洋。有了良好的预测，我们就可以为未来做计划。