Collaborative Research: P2C2--Subdecadal Pleistocene Indian Monsoon Variability: A Dual Archive Perspective

合作研究：P2C2——年代际更新世印度季风变化：双重档案视角

• 批准号: 2103078
• 负责人: Judson Partin
• 金额: $ 8.86万
• 依托单位: University of Texas at Austin
• 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 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103078&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Subdecadal; Pleistocene

The research team seeks to use the Pleistocene record of Indian Monsoon variation to examine how subdecadal rainfall dynamics change under disparate mean-states and global boundary conditions to refine the current understanding of the Indian Monsoon system’s response to climate forcing. Although Pleistocene archives have provided several essential insights into Indian Monsoon dynamics, inferences into subdecadal monsoon variability have been absent due to insufficient sample resolution. Previous reconstructions indicate strong mean-state monsoon responses to variations in insolation and greenhouse gas forcing, but the manner in which subdecadal variability is modulated across these periods is unclear. The current research effort focuses on periods with vastly different greenhouse gas, insolation, and ice-volume conditions to outline the sensitivity of monsoon seasonality and its short-term variability to global climate change. The researchers will apply imaging and mass spectrometric techniques to extract subdecadal hydroclimate signals from previously collected archives from terrestrial and oceanic realms of the Indian subcontinent. Specifically, the team will use previously collected cave stalagmites from peninsular India and sediments from Site U1446 in the Bay of Bengal, for which coarser-scale records of paleomonsoon variability have already been generated.The goal of the research is to help confirm or refute the following hypothesis: (1) seasonality and interannual monsoon variability exhibit a fast (instantaneous) response to gradual insolation forcing; (2) summer and winter monsoon dynamics vary out-of-phase with each other across disparate Pleistocene climate states; and (3) seasonal rainfall in the core monsoon zone and peninsular India is modulated similarly by external forcing.The potential Broader Impacts include integrating state-of-the-art geochemical techniques alongside paleoclimate dynamics to advance knowledge on how climate forcing modulates short-term Indian Monsoon variability and its extremes. The project will support a postdoctoral scholar and will significantly expand her research portfolio. The project will also support undergraduate researchers from underrepresented backgrounds at the University of Arizona and will involve southern Arizona high school students through the SARSEF program. This work will strengthen previously established collaborations between US and Indian scientists, which has enabled successful collection of samples in a societal responsible and mutually beneficial manner.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.

研究小组试图利用印度季风变化的更新世记录来研究在不同的平均状态和全球边界条件下十年间降雨动态如何变化，以完善目前对印度季风系统对气候强迫响应的理解，尽管更新世档案已经提供了一些信息。尽管对印度季风动力学的重要见解，由于之前的重建对变化的平均状态季风响应不足，缺乏对十年以下季风变化的推断。日照和温室气体强迫的影响，但这些时期的年代际变化的调节方式尚不清楚，目前的研究工作重点关注温室气体、日照和冰量条件差异很大的时期，以概述季风季节性和冰量的敏感性。研究人员将应用成像和质谱技术从先前收集的印度陆地和海洋领域的档案中提取十年间的水文气候信号。研究小组将使用之前从印度半岛收集的洞穴石笋和孟加拉湾 U1446 站点的沉积物，这些沉积物已经生成了古季风变化的粗略记录。这项研究的目的是帮助证实或反驳以下假设：（1）季节性和年际季风变化对逐渐日照强迫表现出快速（瞬时）响应；（2）夏季和冬季季风动态变化不同的更新世气候状态彼此不同相；(3) 核心季风区和印度半岛的季节性降雨受到外部强迫的类似调节。潜在的更广泛影响包括整合最先进的地球化学技术该项目将支持一名博士后学者，并显着扩大她的研究范围。这项工作将加强美国和印度科学家之间先前建立的合作，从而以对社会负责和互惠互利的方式成功收集样本。授予 NSF 的法定使命，并通过评估反映使用基金会的智力优点和更广泛的影响审查标准，被认为值得支持。