Poles apart: why has Antarctic sea ice increased, and why can't coupled climate models reproduce observations?

两极分化：为什么南极海冰增加，为什么耦合气候模型不能重现观测结果？

基本信息

批准号：
NE/K011561/1
负责人：
Yevgeny Aksenov
金额：
$ 8.61万
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：
2014
资助国家：
英国
起止时间：
2014 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FK011561%2F1
关键词：
Poles apart why Antarctic sea

项目摘要

Due to its pale colour, sea ice reflects much of the incoming solar radiation back into space, keeping local temperatures relatively cold. However, if warming occurs and sea ice melts, it is replaced by darker ocean. This absorbs more solar energy, causing warming, and so the cycle, the so-called 'ice-albedo feedback' loop, continues. Sea ice also modifies the regional surface energy balance by capping the upper layer of the ocean, reducing its loss of heat to the atmosphere. In addition, sea ice is important because it plays a role in the exchange of carbon dioxide between the atmosphere and ocean, thereby affecting how much of this greenhouse gas is in the atmosphere and contributing to global warming. Moreover, sea ice formation is an important element in driving the global thermohaline circulation of heat and salt through the world's oceans. One component of this circulation is the North Atlantic Drift current that carries warm tropical water across the Atlantic and keeps the UK's winter temperatures much warmer than they would be otherwise.The Intergovernmental Panel on Climate Change (IPCC) assessment reports are an important tool in drivng government policy around the world. However, the present generation of climate models, which are used to predict the future climate scenarios described in these reports, are unable to consistently reproduce the recent increase in Antarctic sea ice. As a result considerable uncertainty must be attached to their predictions of future climate.This proposal aims to both advance our understanding of the Earth's climate and facilitate improved predictions of its future change to aid policy makers. This will be achieved through the following objectives: 1. To explain the key climate processes involved in the recent Antarctic sea ice increase. We know from observations that changes in the near-surface wind around Antarctica are predominantly responsible for the observed increase in sea ice but we don't know exactly how the wind and the ice interact. Using a state-of-the-art computer model of sea ice and the ocean forced by the latest atmospheric data we will establish the key processes through which changes in the wind are causing the ice to increase.2. To establish the ultimate driver of the sea ice increase. Policymakers need to know whether we can attribute the observed changes in Antarctic sea ice to human activity. This might happen through changes in the near-surface winds around Antarctica caused by the 'ozone hole' or greenhouse gas increases for example. Alternatively, it may be simply due to natural variations in the Antarctic climate system. If the former is true, we must determine which human activities are responsible. If the latter is correct, we must try to understand connections between the key processes and wider aspects of the climate system.3. To understand why current climate models fail to simulate the growth in Antarctic sea ice. We will examine the current UK climate model in detail to diagnose which components are to blame and, with our Met Office partner, we will design a development programme to ensure that our findings are transferred into future model improvements in time for the next IPCC report. To help other climate model developers around the world, we will also analyse whether the failings are common to the other models used in the IPCC reports.

由于其浅色，海冰反映了许多传入的太阳辐射回到太空，使局部温度相对较冷。但是，如果发生变暖并融化了海冰，它将被较暗的海洋所取代。这吸收了更多的太阳能，导致变暖，因此循环（所谓的“冰 - 反馈”环路）继续进行。海冰还通过限制海洋上层来修饰区域表面能量平衡，从而减少了其热量损失到大气中。此外，海冰很重要，因为它在大气和海洋之间的二氧化碳交换中发挥作用，从而影响了这种温室气体中有多少大气中的气体并有助于全球变暖。此外，海冰形成是驱动全球热 - 盐热和盐通过世界海洋的重要因素。该循环的一个组成部分是北大西洋漂移电流，该电流在大西洋横跨大西洋，并保持英国的冬季温度比以其他方式温暖得多。政府间气候变化（IPCC）评估报告是Drivng的重要工具。全世界的政府政策。但是，现代的气候模型用于预测这些报告中描述的未来气候场景，无法始终重现南极海冰的最新增加。结果，必须将相当大的不确定性与他们对未来气候的预测有关。该提案旨在促进我们对地球气候的理解，并促进对其未来变化对援助政策制定者的预测。这将通过以下目标来实现：1。解释最近南极海冰增加的关键气候过程。从观察结果中，我们知道，南极周围近地面风的变化主要负责观察到的海冰增加，但我们不知道风和冰是如何相互作用的。使用最新的海冰计算机模型和最新大气数据强迫的海洋模型，我们将建立关键过程，通过这些过程导致冰的变化会增加。2。建立海冰增加的最终驱动力。决策者需要知道我们是否可以将观察到的南极海冰变化归因于人类活动。例如，由于“臭氧孔”或温室气体增加，这可能会发生通过近地面风的变化。另外，这可能仅仅是由于南极气候系统的自然变化。如果前者是正确的，我们必须确定哪些人类活动是负责的。如果后者是正确的，我们必须尝试了解气候系统的关键过程和更广泛方面之间的连接3。要了解为什么当前的气候模型无法模拟南极海冰的生长。我们将详细检查当前的英国气候模型，以诊断应归咎于哪些组件，并且与我们的大都会办公室合作伙伴一起，我们将设计一项开发计划，以确保我们的发现被转移到下一份IPCC报告的未来模型改进中。为了帮助世界各地的其他气候模型开发人员，我们还将分析IPCC报告中其他模型的失败是否共有。

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）

Model sensitivity of the Weddell and Ross seas, Antarctica, to vertical mixing and freshwater forcing

DOI：
10.1016/j.ocemod.2015.08.003
发表时间：
2015-10
期刊：
Ocean Modelling
影响因子：
3.2
作者：
J. Kjellsson;P. Holland;G. Marshall;P. Mathiot;Y. Aksenov;A. Coward;S. Bacon;A. Megann;J. Ridley
通讯作者：
J. Kjellsson;P. Holland;G. Marshall;P. Mathiot;Y. Aksenov;A. Coward;S. Bacon;A. Megann;J. Ridley

Waves, Ice and Ocean in future projections of the Arctic and Southern Ocean.

北冰洋和南大洋未来预测中的波浪、冰和海洋。

DOI：
发表时间：
2018
期刊：
影响因子：
0
作者：
Aksenov, Y.
通讯作者：
Aksenov, Y.

GO5.0: The joint NERC-Met Office NEMO global ocean model for use in coupled and forced applications

DOI：
10.5194/gmd-7-1069-2014
发表时间：
2013-11
期刊：
Geoscientific Model Development
影响因子：
5.1
作者：
A. Megann;D. Storkey;Y. Aksenov;S. Alderson;D. Calvert;T. Graham;P. Hyder;J. Siddorn;B. Sinha-B.-S
通讯作者：
A. Megann;D. Storkey;Y. Aksenov;S. Alderson;D. Calvert;T. Graham;P. Hyder;J. Siddorn;B. Sinha-B.-S

The effects of tides on the water mass mixing and sea ice in the Arctic Ocean