P2C2: Collaborative Research: Defining the paleoclimate-fire relationship in CA across temporal scales through integrated monitoring, stalagmite studies, and proxy system modeling

P2C2：协作研究：通过综合监测、石笋研究和代理系统建模，定义 CA 跨时间尺度的古气候与火灾关系

• 批准号: 2202881
• 负责人: Michael Hren
• 金额: $ 55.26万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2202881&HistoricalAwards=false
• 关键词: P2C2; Collaborative; Research; Defining; paleoclimate

Despite observable increases in the frequency and intensity of wildfires, the relationship between fire, warming, and rainfall variability in California (CA) remains poorly understood. This project will define the relationship between past climate change and wildfire behavior in CA over the last 70,000 years. This will be accomplished by monitoring caves in CA and by assessing evidence of climate change and of wildfires preserved in cave mineral deposits. These deposits, called stalagmites, are capable of documenting past environmental changes continuously over 1000s to 10s of thousands of years. An environmental model that links climate, cave, and wildfire processes will be developed that will advance the understanding of how the climate and fire signals are archived in stalagmites. The model will also be used to build robust reconstructions of the climate-fire relationship at individual cave sites and for transects of caves across CA. Collectively, this research will contribute to building a cohesive picture of how climate in this region responds to global climate change, including warming, and how these changes influence wildfire behavior. Additional deliverables include an open-access, standardized database of all stalagmite records and community accessible software. A cohort of diverse early career scientists and undergraduate and graduate students will be trained through the project using a vertically and laterally integrated training and mentoring program, ‘C3 —Climate Change in California’.This project will test three hypotheses linked by the primary goal of investigating the relationship between regional hydroclimate conditions and wildfire in the fire-prone region of CA, over a variety of timescales and background climate states including periods with no or minimal anthropogenic influence. This will be accomplished by addressing four research objectives. First, a process-based, ‘surface-to-stalagmite’ understanding of the evolution of a suite of hydroclimate and fire tracers will be developed through monitoring of three karst systems representative of different climate conditions in CA. This component will further calibrate promising new proxies (delta-44Ca, 87Sr/86Sr, and a suite of biomarkers) that to date have been applied to few karst systems. Second, a next-generation, multi-proxy karst system model will be built that leverages existing proxy system models and links hydroclimate and fire proxies mechanistically to their suite of environmental and ecologic drivers. Third, a comparable set of calcite, inclusion-fluid, and biomarker proxy records, including novel hydrologic and fire proxies, will be developed for ten stalagmites that define latitudinal and coastal-to-Sierra Nevada transects in CA. Fourth, site-specific and regional proxy-model comparisons will be carried out using Bayesian inversion to produce data-driven quantitative reconstructions of the hydroclimate and fire activity in CA over the past 70 ka. Collectively, this research will provide the basis for future climate modeling efforts focused on constraining the drivers of hydroclimate change and fire activity in the western U.S.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.

尽管野火的频率和强度明显增加，但人们对加利福尼亚州 (CA) 的火灾、变暖和降雨变化之间的关系仍然知之甚少。该项目将确定过去 7 万年里加利福尼亚州过去的气候变化与野火行为之间的关系。这将通过监测加利福尼亚州的洞穴并评估洞穴矿藏中保存的气候变化和野火的证据来实现。这些沉积物（称为石笋）能够持续记录过去的环境变化。将开发一个将气候、洞穴和野火过程联系起来的数千年到数十年的环境模型，这将促进人们对石笋中气候和火灾信号如何存档的理解。该模型还将用于建立稳健的重建。总体而言，这项研究将有助于建立该地区气候如何响应全球气候变化（包括变暖）的整体图景。其他可交付成果包括所有石笋记录的开放式标准化数据库和社区可访问的软件，将通过该项目使用垂直和横向整合的方式对一批不同的早期职业科学家以及本科生和研究生进行培训。培训和指导计划“C3——加利福尼亚州的气候变化”。该项目将测试三个假设，这些假设的主要目标是在不同的时间尺度上调查加利福尼亚州火灾易发地区的区域水文气候条件与野火之间的关系这将通过解决四个研究目标来实现：首先，对一套水文气候和火灾示踪剂的演变进行基于过程的“从地表到石笋”的了解。该组件将通过监测代表加利福尼亚州不同气候条件的三个喀斯特系统来开发，该组件将进一步校准迄今为止已开发的有前景的新代理（delta-44Ca、87Sr/86Sr 和一套生物标记物）。其次，将建立下一代多代理喀斯特系统模型，该模型利用现有的代理系统模型，并将水文气候和火灾代理与其环境和生态驱动因素机械地联系起来。将为十个石笋开发方解石、包裹体流体和生物标记代理记录，包括新的水文和火代理记录，这些石笋定义了内华达山脉的纬度和沿海横断面。第四，将使用贝叶斯反演进行特定地点和区域代理模型比较，以对过去 70 ka 的水文气候和火灾活动进行数据驱动的定量重建。未来气候建模工作的重点是限制美国西部水文气候变化和火灾活动的驱动因素。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。