Collaborative Research: Spatiotemporal Variability and Drivers of East-west Hydroclimate Anti-phasing in the Midcontinental United States During the Last 2000 Years

合作研究：过去 2000 年美国大陆中部东西向水文气候反阶段的时空变化和驱动因素

• 批准号: 1903628
• 负责人: Broxton Bird
• 金额: $ 22.98万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903628&HistoricalAwards=false
• 关键词: Collaborative; Research; Spatiotemporal; Variability; Drivers

The midcontinental United States (US) is one of the world's largest agricultural centers and home to more than 70 million Americans. In recent decades, hydro-climate events in this region have intensified, with generally more frequent and prolonged flooding in the eastern midcontinental US and more severe and sustained droughts in the west. This east-west pattern of hydro-climate variability may be persistent and long-standing, resulting from natural large-scale ocean-atmosphere circulation regimes, or it may be a more recent manifestation of anthropogenic climate change. Given that instrumental meteorological records typically span no more than ~150 years, investigation of the causes of hydroclimate changes in the Midwest on timescales of hundreds to thousands of years requires analysis of high-resolution paleoclimate records, the development of which is the primary objective of this research. Through geochemical analysis of lake sediment, the researchers will produce a series of records of lake-level and precipitation changes that will span the past 2000 years in order to determine the spatiotemporal patterns and underlying drivers of midcontinental hydro-climate variability. This research will 1) produce a long timescale perspective on hydroclimate that will inform water resource management strategies, and 2) elucidate regional-scale responses of hydro-climate to increasing global temperatures. As part of this project, the investigators will be working with local, state, and federal agencies, including the United States Geological Survey, to incorporate the results of this research into flood model development efforts and fluvial erosion hazard mitigation. The data from this project will additionally inform and benefit research into climate-society interactions, including the impact of abrupt and long-term climate changes on Native American societies that once populated the midcontinental US, but abruptly abandoned much of the region ~600 years ago. Methodologically, there are three specific objectives of this research. 1) The researchers will reconstruct changes in atmospheric circulation and precipitation seasonality in the midcontinental US during the last 2000 years using oxygen isotope (d18O) measurements of carbonate minerals in sediment from two hydrologically open lakes. 2) The researchers will produce records of local hydroclimate conditions (precipitation:evaporation ratios and lake-level variability) using d18O, grain size, carbon:nitrogen, and diatom analysis of sediment from four hydrologically closed lakes. 3) The researchers will statistically evaluate the open and closed lake hydro-climate records in the context of atmosphere-ocean variability known from empirical paleoclimate records and model simulations. Using these approaches, the researchers will quantify the respective influences of atmospheric circulation and precipitation seasonality on regional midcontinental hydro-climate and determine the underlying role(s) of ocean-atmosphere processes. Specifically, the investigators will test three hypotheses. 1) Multi-decadal to centennial hydroclimate variability in the midcontinental US during the last 2000 years was characterized by an east-west hydroclimate dipole with its hinge line located between the Great Plains and Midwest at ~96oW. 2) Hydroclimate dipole variability was driven by atmospheric circulation resembling the Pacific North American mode that altered seasonal precipitation patterns. 3) Midcontinental hydroclimate and atmospheric circulation anomalies were predominantly controlled by Pacific basin atmosphere-ocean processes. A critical component of this research is the education and training of undergraduate and graduate students while actively working to increase diversity in STEM fields by recruiting and supporting women and underrepresented minorities in science. One PhD, 2 MSc, and 4 undergraduate students will be directly supported by this project, while several others supported by other sources will also contribute. Because translation of science to the public is a critical component of any effective research project, the researchers and their institutions will engage in outreach activities including the development of an educational module for 4th to 9th grade students focused on 1) Midwest climate, both paleo and modern, 2) paleoclimate reconstruction techniques, and 3) water resource variability. This module will be developed and implemented by IUPUI's Center for Earth and Environmental Sciences and made publicly available for other educators to use. The researchers will work with the Indiana State Museum to incorporate the projects results into an interactive exhibit on midcontinental Native Americans.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.

美国中部是世界上最大的农业中心之一，拥有7000多万美国人。近几十年来，该地区的水文气候事件加剧，美国中部大陆东部的洪水普遍更加频繁和持久，西部的干旱更加严重和持续。这种东西向的水文气候变化格局可能是持久和长期的，是大规模自然海洋-大气环流机制造成的，也可能是人为气候变化的一种较近期的表现。鉴于仪器气象记录通常跨度不超过150年，在数百至数千年的时间尺度上的中西部水文气候变化的原因调查需要分析高分辨率的古气候记录，其中的发展是本研究的主要目标。通过对湖泊沉积物的地球化学分析，研究人员将产生一系列跨越过去2000年的湖泊水位和降水变化记录，以确定中大陆水文气候变化的时空模式和潜在驱动因素。这项研究将1）产生一个长期的水文气候的角度来看，将告知水资源管理战略，和2）阐明水文气候的区域尺度的全球气温上升的反应。作为该项目的一部分，研究人员将与地方、州和联邦机构（包括美国地质调查局）合作，将这项研究的结果纳入洪水模型开发工作和减轻河流侵蚀危害。该项目的数据还将为气候与社会相互作用的研究提供信息，包括突然和长期的气候变化对曾经居住在美国中部大陆的美洲原住民社会的影响，但在600年前突然放弃了该地区的大部分地区。 从方法论上讲，本研究有三个具体目标。1)研究人员将利用两个水文开放湖泊沉积物中碳酸盐矿物的氧同位素（d18 O）测量，重建过去2000年美国中部大陆大气环流和降水季节性的变化。2)研究人员将使用d18 O，粒度，碳：氮和硅藻分析四个水文封闭湖泊的沉积物来记录当地水文气候条件（降水：蒸发比和湖泊水位变化）。3)研究人员将在从经验古气候记录和模型模拟中已知的大气-海洋变化的背景下，对开放和封闭的湖泊水文气候记录进行统计评估。利用这些方法，研究人员将量化大气环流和降水季节性对区域中部水文气候的各自影响，并确定海洋-大气过程的潜在作用。具体而言，研究人员将测试三个假设。1)在过去的2000年里，美国中部大陆的数十年到百年水文气候变率的特征是东西向的水文气候偶极子，其枢纽线位于大平原和中西部之间，约96 oW。2)水文气候偶极变率是由类似于太平洋北美模式的大气环流驱动的，这种模式改变了季节性降水模式。3)中陆水文气候和大气环流异常主要受太平洋海盆海气过程控制。这项研究的一个关键组成部分是本科生和研究生的教育和培训，同时积极努力通过招募和支持科学领域的女性和代表性不足的少数民族来增加STEM领域的多样性。一名博士，2名硕士和4名本科生将直接得到该项目的支持，而其他来源的其他几个人也将做出贡献。因为科学的翻译给公众是任何有效的研究项目的一个重要组成部分，研究人员和他们的机构将从事外展活动，包括为4至9年级的学生开发一个教育模块，重点是1）中西部气候，古和现代，2）古气候重建技术，和3）水资源的变化。该模块将由IUPUI的地球和环境科学中心开发和实施，并公开提供给其他教育工作者使用。研究人员将与印第安纳州博物馆合作，将项目成果纳入一个关于美国中部土著人的互动展览。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智力价值和更广泛的影响审查标准进行评估来支持。

项目成果

Using sediment accumulation rates in floodplain paleochannel lakes to reconstruct climate-flood relationships on the lower Ohio River

• DOI: 10.1016/j.quascirev.2022.107852
• 发表时间: 2022-12
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: Derek K. Gibson;B. Bird;H. Pollard;Cameron A. Nealy;R. Barr;J. Escobar

Fluvial responses to late Holocene hydroclimate variability in the midcontinental United States

• DOI: 10.1016/j.quascirev.2022.107939
• 发表时间: 2023-02
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: Maxwell N. Wright;B. Bird;Derek K. Gibson;H. Pollard;J. Escobar;R. Barr

Differences in forest composition following two periods of settlement by pre-Columbian Native Americans

前哥伦布时期美洲原住民两个时期定居后森林组成的差异

• DOI: 10.1007/s00334-021-00864-9
• 发表时间: 2022
• 期刊: Vegetation History and Archaeobotany
• 影响因子: 2.5
• 作者: Commerford, Julie L.;Gittens, Gabrielle;Gainforth, Sydney;Wilson, Jeremy J.;Bird, Broxton W.
• 通讯作者: Bird, Broxton W.