Assessing simulations of Southern Hemisphere tropospheric jet, meridional overturning circulation of the Southern Ocean and carbon uptake

评估南半球对流层急流、南大洋经向翻转环流和碳吸收的模拟

基本信息

批准号：
NE/J005339/1
负责人：
Emily Shuckburgh
金额：
$ 11.64万
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：
2011
资助国家：
英国
起止时间：
2011 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ005339%2F1
关键词：
Assessing simulations Southern Hemisphere tropospheric

项目摘要

Of the carbon dioxide emissions human activities generate each year, only about half stay in the atmosphere. The rest are taken up by the land and the oceans, in approximately equal measure. At present the Southern Ocean that encircles Antarctica accounts for just under half of the total ocean uptake. Were it not to do so, carbon dioxide levels in the atmosphere would increase at a significantly faster rate than we currently observe. The world's oceans are connected by a vast, slow circulation system with water sinking in the North Atlantic, travelling southward, and then rising to the surface in the Southern Ocean. When it reaches the surface, this water is able to exchange carbon dioxide with the atmosphere, before the circulation dips below the surface again, locking the carbon dioxide in the ocean, and returns north. If that circulation were to change, the carbon uptake of the Southern Ocean would change. So a key question to scientists to answer is, will climate change invoke changes to the overturning circulation of the Southern Ocean? If the answer is yes, then this could change the amount of carbon dioxide in the atmosphere and act as a strong feedback on climate change. Concern has been raised recently because some observations have indicated that indeed the Southern Ocean is taking up less carbon dioxide than we would have historically expected given the current atmospheric carbon dioxide concentrations.So how might climate change be impacting the Southern Ocean overturning circulation? Strong winds blow around Antarctic over the Southern Ocean. The winds directly drive a circulation that is directed northward at the surface. They also indirectly drive a circulation in the opposite direction, i.e. southward at the surface, via their influence on the generation of ocean storms, known as "eddies". The resultant circulation, which is directed northward at the surface, is a subtle balance of these opposing circulations. The winds have been observed to increase in recent decades. Two changes to the atmosphere are thought to have instigated the change in the winds, both of which have human cause: the increase in greenhouse gases in the atmosphere and the decrease in ozone in the stratosphere. It is reasonable to ask therefore whether the carbon uptake of the Southern Ocean might be influenced in the future by changes to the atmospheric concentration of greenhouse gases and by the recovery of the ozone layer. Computer models used to project future climate can only address this question if they are able to properly represent the different physical processes in the atmosphere and ocean that link the atmospheric composition to ocean carbon uptake via the Southern Ocean winds. This project aims to evaluate the representation of these processes in the latest generation of models that will be used as a basis for the next IPCC report.

人类活动每年都会产生二氧化碳排放量，只有一半留在大气中。其余的人被土地和海洋占据，大致相等。目前，环绕南极洲的南大洋占总海洋吸收的一半。如果不这样做，大气中的二氧化碳水平将比我们目前观察到的速度明显更快。世界的海洋通过一个巨大，缓慢的循环系统连接，北大西洋下水道，向南行驶，然后升至南大洋的地面。当它到达表面时，这种水能够将二氧化碳与大气交换，然后循环再次下降到地面以下，将二氧化碳锁定在海洋中，然后向北返回。如果要改变这种循环，南大洋的碳吸收将会改变。因此，对于科学家来说，一个关键的问题是，气候变化会引起南大洋倾覆的循环的变化吗？如果答案是肯定的，那么这可能会改变大气中二氧化碳的量，并充当对气候变化的强烈反馈。最近引起了人们的关注，因为一些观察结果表明，鉴于当前大气二氧化碳的浓度，南大洋的二氧化碳占二氧化碳的占二氧化碳的含量少。那么，气候变化将如何影响南方海洋的循环？强风在南大洋上绕着南极吹来。风直接驱动循环，该循环在表面向北驱动。它们还通过影响着海洋风暴的影响（称为“涡流”）的影响，间接地朝相反的方向驱动循环，即在地面向南。所得的循环是在地表向北的，是这些相反循环的微妙平衡。近几十年来，已经观察到风增加。人们认为对大气的两种变化都煽动了风的变化，这两种变化都有人类原因：大气中的温室气体的增加以及平流层中臭氧的减少。因此，可以合理地询问南大洋的碳吸收是否会因变化温室气体的大气浓度以及臭氧层的回收而影响。用于投影未来气候的计算机模型只有能够正确地代表大气和海洋中的不同物理过程，这些过程将大气成分与海洋碳吸收通过南部的海风连接起来。该项目旨在评估最新一代模型中这些过程的表示，这些模型将用作下一个IPCC报告的基础。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Assessment of Southern Ocean water mass circulation and characteristics in CMIP5 models: Historical bias and forcing response

DOI：
10.1002/jgrc.20135
发表时间：
2013-04
期刊：
Journal of Geophysical Research
影响因子：
0
作者：
J. Sallée;E. Shuckburgh;N. Bruneau;A. Meijers;T. Bracegirdle;Zhaomin Wang;T. Roy
通讯作者：
J. Sallée;E. Shuckburgh;N. Bruneau;A. Meijers;T. Bracegirdle;Zhaomin Wang;T. Roy

Assessment of Southern Ocean mixed-layer depths in CMIP5 models: Historical bias and forcing response