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: 2103077
• 负责人: Kaustubh Thirumalai
• 金额: $ 41.66万
• 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 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103077&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.

尽管更新世档案提供了对印度季风动态的几种基本见解，但由于样本分辨率不足，由于不足而没有推断季风差异。先前的重建表明，强烈的均值季风对日期和温室气体强度的变化有很强的反应，但是在这些时期内调节子量的可变性的方式尚不清楚。当前的研究工作重点是具有截然不同的温室气体，隔离和冰量条件的时期，以概述季风季节性的敏感性及其对全球气候变化的短期差异。研究人员将采用成像和质谱技术来从印度次大陆的陆地和海洋领域中从先前收集的档案中提取亚地区的氢化气候信号。具体而言，该团队将使用先前收集的印度半岛的洞穴石匠和孟加拉湾的U1446的沉积物，为此，已经产生了古代索的可变性的Corser尺度记录。该研究的目的是帮助确认或反驳以下假设：（1）季节性和间隔性（1）隔离性（1）隔离性（1）快速（即隔开性），即（2）夏季和冬季季风动力学在不同的更新世气候状态下彼此之间彼此不同； （3）核心季风区和半岛印度的季节性降雨受到外部强迫的类似调节。潜在的广泛影响包括将最先进的地球化学技术与古气候动态融为一体，以提高对气候强迫调节方式短期印度季风差异的知识。该项目将支持博士后科学，并将大大扩大其研究组合。该项目还将支持亚利桑那大学代表性不足背景的本科研究人员，并通过SARSEF计划涉及亚利桑那州南部高中生。这项工作将加强美国与印度科学家之间以前建立的合作，这使得成功地以社会负责和互惠互利的方式收集样本。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子和更广泛的影响来评估NSF的法定使命。

项目成果

Solar Irradiance Modulates the Asian Summer Monsoon—ENSO Relationship Over the Last Millennium

• DOI: 10.1029/2023gl105708
• 发表时间: 2023-12
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Xiaojing Du;Sylvia Dee;Jun Hu;K. Thirumalai

When Eastern India Oscillated Between Desert Versus Savannah‐Dominated Vegetation

• DOI: 10.1029/2022gl099417
• 发表时间: 2022-08
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Coralie Zorzi;S. Desprat;C. Clément;Kaustubh Thirumalaï;D. Oliviera;K. Anupama;S. Prasad;P. Martinez

Chasing Interannual Marine Paleovariability

追逐年际海洋古变率

• DOI: 10.1029/2023pa004723
• 发表时间: 2023
• 期刊: Paleoceanography and Paleoclimatology
• 影响因子: 3.5
• 作者: Thirumalai, Kaustubh;Maupin, Christopher R.
• 通讯作者: Maupin, Christopher R.