Pliocene Gateways ('PlioGate')

上新世网关（“PlioGate”）

• 批准号: NE/J012726/1
• 负责人: Paul Valdes
• 金额: $ 6.35万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FJ012726%2F1
• 关键词: Pliocene; Gateways; PlioGate

In the wake of rising greenhouse gases, such as carbon dioxide (CO2) and methane, how will the climate evolve over the next 100 years? This question is paramount in the minds of scientists and politicians alike. However, despite over 100 years of research into climate sensitivity, the range of projected future warming remains startling wide; 1.5 to 6.1 degrees C for a doubling of atmospheric CO2. The disagreement between projections made by different climate models makes a considerable contribution to this uncertainty.Because a compromise must be reached between the limits of technology and our knowledge of climate processes, climate models are necessarily approximations of reality. As a result, all models differ in terms of the processes they represent and the resolution they run at. This is why climate models produce different results even though they are based on the same mathematical principles. It is also why it is crucial to test the models, to make sure that they really are capable of simulating Earth's climate.As there are no observations for future climate change, we look to the past to evaluate climate models. The instrumental record provides one such test of the model. However, throughout the short duration of our instrumental record, climate change has been small in comparison to projected changes for the next 100 years. This makes the instrumental record an inadequate definitive test of the models and we must test the models in other time periods too.The last time atmospheric CO2 was as high as today was during a period known as the late Pliocene, specifically around 3 million years ago. Obviously there are no direct observations from so long ago, but evidence from fossil-remains of Pliocene fauna and flora show a climate-dependent chemical and biological signal, which we can use to reconstruct the climate conditions that these fauna and flora lived in. The conclusions from this work suggest that climate was 2 to 3 degrees C warmer than the Pre-Industrial era, with particularly large amplitude warming in the N.Atlantic and Greenland-Iceland-Norwegian Sea. Therefore, the parallels between the Pliocene and future scenarios makes the Pliocene an ideal test case for models used to project future climate change.To date, model simulations for this period have been able to simulate the overall warmth of the Pliocene, but fail to reproduce the large amplitude warmth in the N.Atlantic GIN Sea. Recently, under the auspices of the international PlioMIP project, 14 different state-of-the-art climate models have been run for this period, but all have failed to reproduce the N.Atlantic/GIN Sea warming.We suggest that this mismatch is symptomatic of inadequate representation of ocean gateways during the Pliocene, rather than a fundamental error in climate models during warm periods. Recent work at the University of Bristol has showed that changing the way ocean gateways are set-up in a model of modern climate can impact regional climates by 5 degrees C or more. This proposal will investigate the role of two key ocean gateways, namely the Bering and Gibraltar Straits. Nobody has ever investigated whether changes in their exchange could have had an impact on Pliocene climate, despite the fact that there is evidence that the gateways were different and that they can have a big impact on climate. The results from the project will make a considerable contribution to improving our understanding of Pliocene climates and whether climate models work for past warm intervals.

随着二氧化碳（CO2）和甲烷等温室气体的增加，未来100年气候将如何演变？这个问题在科学家和政治家的心目中都是至关重要的。然而，尽管对气候敏感性的研究已经进行了100多年，但预计未来变暖的范围仍然惊人地宽;大气二氧化碳增加一倍的温度为1.5至6.1摄氏度。不同气候模式所作的预测之间的不一致是造成这种不确定性的一个重要因素，因为必须在技术的局限性和我们对气候过程的认识之间达成妥协，气候模式必然是对现实的近似。因此，所有模型在它们表示的过程和它们运行的分辨率方面都不同。这就是为什么气候模型产生不同的结果，即使它们是基于相同的数学原理。这也是为什么对模型进行测试是至关重要的，以确保它们确实能够模拟地球的气候。由于没有对未来气候变化的观测，我们期待过去评估气候模型。仪器记录提供了一个这样的测试模型。然而，在我们的仪器记录的短暂时间内，气候变化与未来100年的预测变化相比是很小的。这使得仪器记录不足以对模型进行确定性测试，我们必须在其他时间段对模型进行测试。上一次大气中的二氧化碳含量达到今天的水平是在上新世晚期，具体来说是在大约300万年前。很明显，没有这么久以前的直接观测，但上新世动物群和植物群化石遗迹的证据显示了一种依赖于气候的化学和生物信号，我们可以用它来重建这些动物群和植物群生活的气候条件。这项工作的结论表明，气候比前工业时代高2至3摄氏度，北大西洋和格陵兰-冰岛-挪威海的变暖幅度特别大。因此，上新世与未来情景之间的相似之处使上新世成为预测未来气候变化的模型的理想测试案例。迄今为止，这一时期的模型模拟已经能够模拟上新世的整体温暖，但未能重现北大西洋GIN海的大幅温暖。最近，在国际PlioMIP项目的主持下，14个不同的国家的最先进的气候模式已经运行了这一时期，但都未能再现北大西洋/GIN海warming.We建议，这种不匹配是症状的海洋网关在上新世的代表性不足，而不是在温暖时期的气候模式的根本错误。布里斯托大学最近的研究表明，在现代气候模型中改变海洋门户的设置方式可以对区域气候产生5摄氏度或更多的影响。这项建议将调查两个主要的海洋门户，即白令海峡和直布罗陀海峡的作用。没有人曾经调查过它们交换的变化是否会对上新世气候产生影响，尽管有证据表明网关是不同的，它们可以对气候产生重大影响。该项目的结果将为提高我们对上新世气候的理解以及气候模型是否适用于过去的温暖时期做出相当大的贡献。

项目成果

On the identification of a Pliocene time slice for data-model comparison.

• DOI: 10.1098/rsta.2012.0515
• 发表时间: 2013-10-28
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Haywood AM;Dolan AM;Pickering SJ;Dowsett HJ;McClymont EL;Prescott CL;Salzmann U;Hill DJ;Hunter SJ;Lunt DJ;Pope JO;Valdes PJ
• 通讯作者: Valdes PJ

Modelling global-scale climate impacts of the late Miocene Messinian Salinity Crisis

• DOI: 10.5194/cp-10-607-2014
• 发表时间: 2014-01-01
• 期刊: CLIMATE OF THE PAST
• 影响因子: 4.3
• 作者: Ivanovic, R. F.;Valdes, P. J.;Gutjahr, M.
• 通讯作者: Gutjahr, M.

Climate model and proxy data constraints on ocean warming across the Paleocene-Eocene Thermal Maximum

• DOI: 10.1016/j.earscirev.2013.07.004
• 发表时间: 2013-10-01
• 期刊: EARTH-SCIENCE REVIEWS
• 影响因子: 12.1
• 作者: Dunkley Jones, Tom;Lunt, Daniel J.;Maslin, Mark
• 通讯作者: Maslin, Mark

Numerical simulations of oceanic oxygen cycling in the FAMOUS Earth-System model: FAMOUS-ES, version 1.0

FAMOUS 地球系统模型中海洋氧循环的数值模拟：FAMOUS-ES，版本 1.0

• DOI: 10.5194/gmd-7-1419-2014
• 发表时间: 2014
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: Williams J

Sensitivity of modern climate to the presence, strength and salinity of Mediterranean-Atlantic exchange in a global general circulation model

• DOI: 10.1007/s00382-013-1680-5
• 发表时间: 2014-02-01
• 期刊: CLIMATE DYNAMICS
• 影响因子: 4.6
• 作者: Ivanovic, Ruza F.;Valdes, Paul J.;Gutjahr, Marcus
• 通讯作者: Gutjahr, Marcus