Collaborative Research: P2C2--2000 Years of Variability in the Southern Annular Mode from Tree Rings and Ice

合作研究：P2C2--2000年树木年轮和冰的南环模态变化

• 批准号: 1803946
• 负责人: Kevin Anchukaitis
• 金额: $ 14.99万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1803946&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; 2000; Years

This project aims to use new data from King Billy pine trees (Athrotaxis selaginella) located on subalpine ridges in southern Tasmania, Australia, in combination with two high-resolution East Antarctic ice cores, to reconstruct the behavior of the Southern Annular Mode (SAM) over the last 2,000 years. This is important because the SAM influences not only Southern Hemisphere climate but also carbon and heat uptake and Antarctic ice melt.The SAM is the leading mode of climate variability in the middle to high latitudes of the Southern Hemisphere, where it affects the strength and position of the westerly winds and, therefore, precipitation and temperature anomalies across oceans and continents. The SAM controls the strength and position of the Southern Hemisphere westerlies, and therefore links large-scale climate anomalies across multiple continents and oceans. These subpolar winds also modulate the uptake of heat and carbon by the Southern Ocean and affect the cryosphere.While investigations of Northern Hemisphere climate dynamics have benefitted from a robust network of annually resolved climate proxies, the Southern Hemisphere has far more limited paleoclimate data during the Common Era, particularly in the Indian Ocean sector, the most climate data-sparse region globally. The recently discovered sub-fossil wood from King Billy pine trees provides a new opportunity for generating multi-millennial reconstructions of regional temperature and sea level pressure - key indicators of the SAM at mid-latitudes. This network of tree sites builds on and complements another emerging network of high-resolution climate records from east Antarctic ice. A new environmental reconstruction, centered on the Indian Ocean sector of the Southern Hemisphere, will help address significant uncertainties in existing SAM reconstructions from the Pacific sector and allow an assessment of the role of internal dynamics and natural forcing of Southern Hemisphere climate prior to human modifications of the atmosphere. Further, new data and reconstructions help make possible identification and quantification of uncertainty related to proxy type, location, and seasonality, and the influence of these on inferences about the timing and emergence of trends in the SAM. New environmental and climatological reconstructions also help explore what drives variability in this dynamical feature. These new reconstructions may extend existing reconstructions of SAM from the Antarctic Peninsula by at least 1,000 years. Greater understanding of the long-term variability of SAM and its links to Indian Ocean and ENSO dynamics, as well as to external forcing mechanisms (e.g ozone depletion, greenhouse gases) using data-model comparison techniques is possible. This project strengthens international collaborations between American and Australian scientists as well as across paleoclimate disciplines (tree rings and ice cores).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目旨在使用位于澳大利亚塔斯马尼亚塔斯马尼亚南部亚高山山脊的国王比利·松树（Athrotaxis selaginella）的新数据，并结合了过去2,000年的两种高分辨率东南极冰芯，以重建南方环形模式（SAM）的行为。这很重要，因为SAM不仅会影响南半球气候，而且会影响碳和热吸收和南极冰融化。SAM是南半球中部到高纬度地区气候变化的领先模式，在那里它影响了海洋风的强度和位置，因此，气风风和跨海和温度的海洋和温度，海洋和温度越来越多。 SAM控制着南半球西风的强度和位置，因此将各大洲和海洋的大规模气候异常联系起来。这些亚极风还调节了南海洋的热量和碳的吸收，并影响冰冻圈。北半球气候动态的调查受益于每年稳健的气候代理网络，而南半球的稳健网络是在印度海洋地区的普通时代，尤其是在印度海洋地区，最有限的古气候数据，尤其是最有限的古气候数据。 最近发现的来自国王比利松树的亚化石木为产生区域温度和海平面压力的多千年重建提供了一个新的机会 - 中纬度中SAM的关键指标。该树地点网络建立在并补充了来自东南极冰的另一个高分辨率气候记录的新兴网络。以南半球印度洋部门为中心的一项新的环境重建将有助于解决太平洋部门现有的SAM重建中的重大不确定性，并允许评估内部动力学和自然强迫南半球气候的作用，然后再进行人类大气改造。 此外，新的数据和重建有助于对与代理类型，位置和季节性相关的不确定性进行识别和量化，以及这些对SAM趋势的时机和出现的推论的影响。 新的环境和气候重建还有助于探索这一动力学功能的变异性的原因。这些新的重建可能会将来自南极半岛的SAM现有重建延长至少1000年。 可以通过数据模型比较技术对SAM及其与印度洋和ENSO动力学的长期变化及其与外部强迫机制（例如臭氧耗竭，温室气体）的联系更深入了解。该项目加强了美国和澳大利亚科学家之间的国际合作以及整个古气候学科（树环和冰核）。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估来评估值得支持的。

项目成果

A data assimilation approach to last millennium temperature field reconstruction using a limited high-sensitivity proxy network

使用有限高灵敏度代理网络重建上千年温度场的数据同化方法

• DOI: 10.1175/jcli-d-20-0661.1
• 发表时间: 2021
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: King, Jonathan M.;Anchukaitis, Kevin J.;Tierney, Jessica E.;Hakim, Gregory J.;Emile-Geay, Julien;Zhu, Feng;Wilson, Rob
• 通讯作者: Wilson, Rob

Investigating the potential for Southern Hemisphere climate reconstruction using stable isotopes in Tasmanian tree rings

研究利用塔斯马尼亚树木年轮中的稳定同位素重建南半球气候的潜力

• DOI: 10.1016/j.dendro.2022.126016
• 发表时间: 2022
• 期刊: Dendrochronologia
• 影响因子: 3
• 作者: Grzywacz, Zachary;Hessl, Amy;Anchukaitis, Kevin;Sharma, Shikha;Evans, Michael N.;Nichols, Scott
• 通讯作者: Nichols, Scott

Relationship Between Weather Regimes and Atmospheric Rivers in East Antarctica

• DOI: 10.1029/2021jd035294
• 发表时间: 2021-12
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: B. Pohl;V. Favier;J. Wille;Danielle G. Udy;T. Vance;J. Pergaud;Niels Dutrievoz;J. Blanchet;C. Kittel;C. Amory;G. Krinner;Francis Codron

High Resolution Radiocarbon Spike Confirms Tree Ring Dating with Low Sample Depth

• DOI: 10.1016/j.dendro.2022.126048
• 发表时间: 2022-12
• 期刊: Dendrochronologia
• 影响因子: 3
• 作者: Meagan Walker;Alexis Mueller;K. Allen;Pavla Fenwick;V. Agrawal;K. Anchukaitis;A. Hessl