Collaborative Research: Sensitivity of Walker circulation to CO2 forcing during the late Pliocene as an analogue for future climate change

合作研究：上新世晚期沃克环流对二氧化碳强迫的敏感性作为未来气候变化的类比

• 批准号: 2103015
• 负责人: Tripti Bhattacharya
• 金额: $ 20.09万
• 依托单位: Syracuse University
• 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: 2021-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103015&HistoricalAwards=false
• 关键词: Collaborative; Research; Sensitivity; Walker; circulation

The proposed study will produce new measurements and simulations of the late-Pliocene (3.3 – 2.58 million years ago) to determine how the Pacific Walker Circulation responds to a warmer climate. The Pacific Walker Circulation is a key feature of the climate system; it impacts temperature and rainfall worldwide, with important socioeconomic consequences. The late Pliocene is an attractive target for understanding sensitivity of Pacific Walker Circulation to changes in atmospheric carbon dioxide concentrations because it features biome distributions, geography, and topography that are similar to the present-day. Carbon dioxide concentration decreased from roughly today’s level during the mid-Piacenzian (3.3 – 3.0 million years ago) to around the preindustrial level during the early-Pleistocene (2.58 million years ago), coincident with (and perhaps driving) the expansion of Northern Hemisphere ice sheets. The study will produce new geochemical data (sedimentary leaf wax isotope data from both western and eastern sides of the tropical Pacific) and will develop water isotopologue tracking enabled Earth System Model simulations to investigate Pacific Walker Circulation sensitivity to late-Pliocene changes in carbon dioxide concentrations and ice sheets. The products will contribute to the existing archives of Pliocene Earth System simulations and observations, providing a community resource for future research and education. A collection of educational activities at high school, undergraduate, and graduate level are also planned to train next generation climate scientists. Strengthening of the Pacific Walker Circulation in response to carbon dioxide increase is a common prediction from atmosphere-ocean coupled Earth System Models. Yet, confidence in this prediction is low due to the short duration of instrumental records, which only chronicle a narrow range of transient climate responses to carbon dioxide increase. This project aims to test model predictions of changes in Pacific Walker Circulation during the late-Pliocene with measurements of deuterium concentrations of sedimentary leaf wax from both western and eastern sides of the tropical Pacific. The team will develop a series of water isotopologue tracking enabled Earth System Model simulations and leaf wax records to understand 1) whether a weaker Pacific Walker Circulation existed during the mid-Piacenzian; 2) what is the sensitivity of Pacific Walker Circulation to carbon dioxide decline during the late-Pliocene; and 3) if the early-Pleistocene glacial expansion strengthened the Pacific Walker Circulation.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.

这项拟议中的研究将对上新世晚期（330万至258万年前）进行新的测量和模拟，以确定太平洋沃克环流如何对气候变暖做出反应。太平洋沃克环流是气候系统的一个关键特征；它影响全球的温度和降雨，并产生重要的社会经济后果。上新世晚期是了解太平洋沃克环流对大气二氧化碳浓度变化敏感性的一个有吸引力的目标，因为它具有与当今相似的生物群落分布、地理和地形特征。二氧化碳浓度从皮亚琴世中期（330万- 300万年前）的大致今天的水平下降到早更新世（258万年前）的工业化前水平，与北半球冰盖的扩张相一致（也可能推动了）。该研究将产生新的地球化学数据（来自热带太平洋西部和东部的沉积叶蜡同位素数据），并将开发水同位素跟踪地球系统模型模拟，以研究太平洋沃克环流对上新世晚期二氧化碳浓度和冰盖变化的敏感性。这些产品将有助于现有的上新世地球系统模拟和观测档案，为未来的研究和教育提供社区资源。还计划在高中、本科和研究生阶段开展一系列教育活动，以培养下一代气候科学家。太平洋沃克环流因二氧化碳增加而增强是大气-海洋耦合地球系统模式的常见预测。然而，由于仪器记录的持续时间较短，这种预测的可信度较低，这些记录只记录了二氧化碳增加对短暂气候反应的一个狭窄范围。该项目旨在测试上新世晚期太平洋沃克环流变化的模型预测，方法是测量热带太平洋东西两侧沉积叶蜡的氘浓度。该团队将开发一系列的水同位素跟踪地球系统模型模拟和叶蜡记录，以了解1)在皮亚琴世中期是否存在较弱的太平洋沃克环流；2)上新世晚期太平洋Walker环流对co2下降的敏感性；3)早更新世冰川扩张是否加强了太平洋沃克环流。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

项目成果

Expansion and Intensification of the North American Monsoon During the Pliocene

• DOI: 10.1029/2022av000757
• 发表时间: 2022-11
• 期刊: AGU Advances
• 影响因子: 8.4
• 作者: Tripti Bhattacharya;R. Feng;J. Tierney;Claire B. Rubbelke;N. Burls;Scott Knapp;M. Fu

Biomarker Approaches for Reconstructing Terrestrial Environmental Change

重建陆地环境变化的生物标记方法

• DOI: 10.1146/annurev-earth-032320-095943
• 发表时间: 2022
• 期刊: Annual Review of Earth and Planetary Sciences
• 影响因子: 14.9
• 作者: Inglis, Gordon N.;Bhattacharya, Tripti;Hemingway, Jordon D.;Hollingsworth, Emily H.;Feakins, Sarah J.;Tierney, Jessica E.
• 通讯作者: Tierney, Jessica E.

Patterns and Mechanisms of Northeast Pacific Temperature Response to Pliocene Boundary Conditions

• DOI: 10.1029/2021pa004370
• 发表时间: 2022-06
• 期刊: Paleoceanography and Paleoclimatology
• 影响因子: 3.5
• 作者: P. Brennan;Tripti Bhattacharya;R. Feng;J. Tierney;E. Jorgensen