OCE-PRF Unraveling Southern Hemisphere westerly wind variability through the last ~150 ky using Tasman Sea sediments

OCE-PRF 利用塔斯曼海沉积物揭示了过去约 150 ky 的南半球西风变化

• 批准号: 2126500
• 负责人: Jordan Abell
• 金额: $ 28.07万
• 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: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2126500&HistoricalAwards=false
• 关键词: OCE; PRF; Unraveling; Southern; Hemisphere

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).The Southern Hemisphere westerly winds, commonly referred to as the “westerlies”, play a crucial role in regional and global climate. Modern observations suggest that these winds are moving towards Antarctica and becoming stronger in response to anthropogenic warming. Shifts in the position and intensity of these winds can potentially impact ocean circulation, the distribution of natural and anthropogenic aerosols, and the carbon cycle. As such, developing a better understanding of how the westerly winds change when conditions on Earth were different from today is critical to enhancing our constraints on their future variability. The research proposed here seeks to reconstruct the characteristics of the Southern Hemisphere westerlies during climate states both colder and warmer than today over the last 150,000 years. To accomplish this, PI Abell will develop records of dust fluxes, sea-surface temperatures, and Australian vegetation regimes utilizing marine sediments from several cores in the Tasman Sea. It is the combination of these independent proxies related to the westerly winds, along with sampling multiple cores that cover an ~10° north-south transect, that will allow for information on both the position and strength of the Southern Hemisphere westerlies to be ascertained. As an NSF Postdoctoral Fellow, PI Abell will mentor high school and undergraduate students through several programs. One of these is the Southern Arizona Research, Science, and Engineering Foundation S.T.A.R Labs Program, where he will guide a local high school student through developing and executing a research project related to this proposed research. Additionally, PI Abell will work with a University of Arizona undergraduate student to prepare them for graduate school through the Ronald E. McNair Achievement Program. The proposed project will focus on reconstructing the characteristics of the Southern Hemisphere westerly winds during various climate states over the last ~150 ky. PI Abell will utilize samples from three marine sediment cores spanning ~10° latitude in the Tasman Sea, along with four independent (organic and inorganic) geochemical methods, to investigate shifts in the position and intensity of the westerlies. Specifically, PI Abell will 1) produce constant flux proxy-derived dust flux records based on inorganic dust proxies, 2) use n-alkanes as a dust proxy to develop additional records of dust fluxes that are not influenced by volcanic inputs, 3) generate records of plant-wax carbon isotopes to gain information on C3/C4 vegetation boundaries, and in turn precipitation seasonality, in Australia, and 4) reconstruct shifts in the Subtropical and Tasman Fronts by utilizing the alkenone UK’37 SST proxy. Combined, information from these various proxies will allow for the reconstruction of both the position and intensity of the Southern Hemisphere westerlies during key climatic intervals such as the Holocene, the Last Glacial Maximum, and the last interglacial period. These datasets will be useful to the climate modeling community, as they will provide constraints on the natural variability of the westerlies to changes in potential driving mechanisms such as ice volume and atmospheric temperature gradients, thus aiding essential modeling of future changes in the westerly winds. Interpretations and conclusions drawn from this work will be brought to the public via non-technical settings such as public talks and presentations/activities at The Science Center at the Tucson Festival of Books.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.

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。南半球西风，通常被称为“西风带”，在区域和全球气候中起着至关重要的作用。现代观测表明，这些风正在向南极洲移动，并因人为变暖而变得更强。这些风的位置和强度的变化可能会影响海洋环流、自然和人为气溶胶的分布以及碳循环。因此，更好地了解当地球上的条件与今天不同时西风如何变化，对于加强我们对其未来变化的限制至关重要。这里提出的研究旨在重建过去15万年来比今天更冷和更暖的气候状态下南半球西风带的特征。为了实现这一目标，PI阿贝尔将开发记录的灰尘通量，海面温度，澳大利亚植被状况利用海洋沉积物从几个核心在塔斯曼海。正是这些与西风相关的独立代理的组合，沿着覆盖~10°南北样带的采样多个核心，将允许确定关于南半球西风的位置和强度的信息。作为NSF博士后研究员，PI阿贝尔将通过几个项目指导高中和本科生。其中之一是南亚利桑那州的研究，科学和工程基金会S.T.A.R实验室计划，在那里他将指导当地高中学生通过开发和执行与这项研究有关的研究项目。此外，PI阿贝尔将与亚利桑那大学的本科生，通过罗纳德E准备他们的研究生院。麦克奈尔成就计划该项目的重点是重建南半球西风在过去~150 ky的各种气候状态的特征。PI阿贝尔将利用从塔斯曼海纬度约10°的三个海洋沉积物岩心中采集的样本，沿着四种独立的（有机和无机）地球化学方法，调查西风带位置和强度的变化。具体来说，PI阿贝尔将1）根据无机尘埃代用品产生恒定通量代用品衍生的尘埃通量记录，2）使用正构烷烃作为尘埃代用品，以开发不受火山输入影响的尘埃通量的额外记录，3）生成植物蜡碳同位素记录，以获得关于C3/C4植被边界的信息，进而获得澳大利亚降水季节性，4）利用kenone UK'37 SST代用品重建副热带锋和塔斯曼锋的移动。结合这些不同的代理信息，将允许重建的位置和强度的南半球西风在关键的气候间隔，如全新世，末次冰期最大，末次间冰期。这些数据集将对气候建模界有用，因为它们将为西风带的自然变率提供约束，以限制冰量和大气温度梯度等潜在驱动机制的变化，从而有助于对西风带未来变化进行基本建模。从这项工作中得出的解释和结论将通过非技术性的设置，如图森图书节科学中心的公开讲座和演示/活动，向公众展示。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

项目成果

Evaluating the Drivers of Quaternary Dust Fluxes to the Western North Pacific: East Asian Dustiness and Northern Hemisphere Gustiness

• DOI: 10.1029/2022pa004571
• 发表时间: 2023-08
• 期刊: Paleoceanography and Paleoclimatology
• 影响因子: 3.5
• 作者: J. Abell;G. Winckler;A. Pullen;C. Kinsley;P. Kapp;J. Middleton;F. Pavia;D. McGee;H. Ford;M. Raymo

From Desiccation to Re‐Integration of the Yellow River Since the Last Glaciation

• DOI: 10.1029/2023gl103632
• 发表时间: 2023-08
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Yuqi Zhao;Niannian Fan;J. Nie;J. Abell;Yu An;Zhangdong Jin;Chengshan Wang;Jia-Fu Zhang;Xing-nian Liu;Ruihua Nie

Climate Evolution Through the Onset and Intensification of Northern Hemisphere Glaciation

• DOI: 10.1029/2022rg000793
• 发表时间: 2023-07
• 期刊: Reviews of Geophysics
• 影响因子: 25.2
• 作者: E. McClymont;S. L. Ho;H. L. Ford;I. Bailey;M. Berke;C. Bolton;S. Schepper;G. Grant;J. Groeneveld;G. Inglis;C. Karas;M. O. Patterson;G. Swann;K. Thirumalai;S. M. White;M. Alonso-García;P. Anand;B. Hoogakker;K. Littler;B. Petrick;B. Risebrobakken;J. Abell;A. J. Crocker;F. D. Graaf;S. Feakins;J. C. Hargreaves;C. L. Jones;M. Markowska;A. S. Ratnayake;C. Stepanek;D. Tangunan

A middle Pleistocene to Holocene perspective on sediment sources for the Tengger Desert, China

• DOI: 10.1016/j.catena.2023.107119
• 发表时间: 2023-07
• 期刊: CATENA
• 影响因子: 6.2
• 作者: Maotong Li;J. Nie;Zaijun Li;A. Pullen;J. Abell;Haobo Zhang;Cody A. McMechen;B. Pan

Long‐Term Variability in Pliocene North Pacific Ocean Export Production and Its Implications for Ocean Circulation in a Warmer World

• DOI: 10.1029/2022av000853
• 发表时间: 2023-08
• 期刊: AGU Advances
• 影响因子: 8.4
• 作者: J. Abell;G. Winckler