Collaborative Research: P2C2: Re-assessing Pliocene and Miocene warm climates and identifying the 'missing physics' to explain them

合作研究：P2C2：重新评估上新世和中新世温暖气候并确定“缺失的物理学”来解释它们

基本信息

批准号：
1602557
负责人：
Pincelli Hull
金额：
$ 30万
依托单位：
Yale University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-15 至 2019-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602557&HistoricalAwards=false
关键词：
Collaborative Research P2C2 Re assessing

项目摘要

Many of the long-term trends and transitions in climate over the past 65 million years are correlated with major changes in atmospheric carbon dioxide concentrations. But not all. Periods lasting hundreds of thousands or millions of years, for example during the Miocene and Pliocene, are loosely correlated with CO2 changes that are too small-- at least according to climate models-- to generate the large climate changes evidenced in proxy records. The purpose of this study is to investigate Miocene and Pliocene climate, with an emphasis on understanding the mechanisms responsible for widespread warmth, reduced temperature gradients, and apparently high climate sensitivity. Climate models have been unable previously to reproduce these features, raising concerns regarding their ability to correctly predict future warming. This study is novel and significant because a multi-disciplinary team combining expertise in paleoclimate data, models, and theory will generate geographically widespread, multiproxy past climate records. This data will be compared with new and advanced modeling approaches. A benefit of this approach is that climate models will be improved by this comparison with past data and the lessons learned will lead eventually to improved predictions of future climate change. Specifically, although significant progress has been achieved in understanding of Miocene and Pliocene climates, explanations are lacking for some their basic elements, such as: weakened meridional temperature gradients, weakened zonal temperature gradients across the Pacific, and preferential warming in polar regions, in upwelling regions, and in continental interiors. This study's goals are to better quantify these enigmatic features by developing new geochemical records and compare this data with state-of-the art climate modeling that will enable better prediction of the Earth system to greenhouse gas and non-greenhouse gas forcing. To accomplish this, the project will: (1) Enhance understanding of the signal being recorded by various paleoclimate proxies for sea surface temperature (SST) and generate a suite of new TEX86 and Uk37 paleo-SST records, complemented by existing records, to provide a comprehensive view of evolving surface ocean conditions from the mid Miocene through the Pliocene. (2) Conduct simulations of mid-Miocene and mid-Pliocene climate using the Community Earth System Model (CESM), with a new atmospheric component, CAM5, that includes more sophisticated treatment of cloud-aerosol interactions than previous models. Sensitivity studies to cloud microphysical properties and parameterization, including mixed-phase cloud properties and aerosol (sulfate and dust) emissions will be conducted to constrain previously unexplored interactions between cloud microphysics, aerosols and past climates. (3) Simulate Miocene and Pliocene climates using the "Super-parameterized" (SP) version of the CESM. SP-CESM incorporates a cloud-resolving model in each grid cell to represent convection and clouds more explicitly rather than parameterize them, allowing a more accurate representation of convection and cloud effects on the large-scale atmospheric circulation. In addition to the research objectives, the project has education and engagement components. It will fund two graduate students and a female early career research scientist in STEM disciplines. Three public engagement efforts will be conducted, including public lectures, a website for a broad audience, and an afterschool program for high school students.

过去 6500 万年来气候的许多长期趋势和转变都与大气二氧化碳浓度的重大变化相关。但并非全部。持续数十万或数百万年的时期，例如中新世和上新世，与二氧化碳的变化松散相关，这些变化太小——至少根据气候模型——不足以产生代理记录中证明的大规模气候变化。本研究的目的是调查中新世和上新世气候，重点是了解造成广泛变暖、温度梯度减小和明显高气候敏感性的机制。气候模型以前无法重现这些特征，引发了人们对其正确预测未来变暖能力的担忧。这项研究新颖且意义重大，因为一个多学科团队结合了古气候数据、模型和理论的专业知识，将产生地理上广泛的、多代理的过去气候记录。该数据将与新的先进建模方法进行比较。这种方法的一个好处是，通过与过去的数据进行比较，可以改进气候模型，并且吸取的教训最终将改进对未来气候变化的预测。具体而言，尽管对中新世和上新世气候的认识取得了重大进展，但对其一些基本要素仍缺乏解释，例如：经向温度梯度减弱、太平洋地区纬向温度梯度减弱、极地优先变暖、上升流等。地区和大陆内陆地区。这项研究的目标是通过开发新的地球化学记录来更好地量化这些神秘特征，并将这些数据与最先进的气候模型进行比较，从而更好地预测地球系统对温室气体和非温室气体强迫的影响。为了实现这一目标，该项目将：(1) 加强对各种古气候代理记录的海面温度 (SST) 信号的理解，并生成一套新的 TEX86 和 Uk37 古海温记录，并辅以现有记录，以提供从中新世中期到上新世的表面海洋状况演变的综合视图。 (2) 使用社区地球系统模型 (CESM) 进行中新世中期和上新世中期气候的模拟，其中包含新的大气成分 CAM5，其中包括比以前的模型更复杂的云-气溶胶相互作用处理。将进行对云微物理特性和参数化的敏感性研究，包括混合相云特性和气溶胶（硫酸盐和灰尘）排放，以限制云微物理、气溶胶和过去气候之间先前未探索的相互作用。 (3) 使用 CESM 的“超参数化”(SP) 版本模拟中新世和上新世气候。 SP-CESM在每个网格单元中结合了云解析模型，以更明确地表示对流和云，而不是参数化它们，从而可以更准确地表示对流和云对大规模大气环流的影响。除了研究目标外，该项目还具有教育和参与部分。它将资助 STEM 学科的两名研究生和一名女性早期职业研究科学家。将开展三项公众参与工作，包括公开讲座、面向广大受众的网站以及针对高中生的课外活动。

项目成果

期刊论文数量（2）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Pliocene decoupling of equatorial Pacific temperature and pH gradients

上新世赤道太平洋温度和 pH 梯度的解耦

DOI：
10.1038/s41586-021-03884-7
发表时间：
2021-10-01
期刊：
Nature
影响因子：
64.8
作者：
M. Shankle;N. Burls;A. Fedorov;M. Thomas;Wei Liu;D. Penman;H. Ford;Peter H Jacobs;N. Planavsky
通讯作者：
N. Planavsky

The latitudinal temperature gradient and its climate dependence as inferred from foraminiferal δ 18 O over the past 95 million years

根据过去9500万年有孔虫Î´ 18 O推断的纬度温度梯度及其气候依赖性