Collaborative Research: P2C2--Medieval to Modern Climate Variability and Climate Change in the Great Plains

合作研究：P2C2——中世纪到现代的气候变率和大平原的气候变化

• 批准号: 2201653
• 负责人: Edward Cook
• 金额: $ 18万
• 依托单位: Columbia University
• 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: 2022-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2201653&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Medieval; Modern

The general goal of the research is to develop moisture sensitive tree-ring chronologies from old-growth populations of Juniperus, Pinus, and Taxodium trees from within or near the Great Plains for in situ reconstructions of seasonal precipitation and the long-term soil moisture balance that together will constitute the Great Plains Drought Atlas (GPDA). Five gridded reconstructions that span the Great Plains at 0.5 degree resolution will be developed, including the Standardized Precipitation Index (SPI) for the spring and summer seasons, precipitation totals for spring and summer, and the summer Palmer Drought Severity Index (PDSI). The reconstructions will be designed for maximum length, with the goal of extending the moisture estimates into the Medieval Period when the climate appears to have been much warmer and drier. The GPDA will be used to test hypotheses concerning the magnitude of Great Plains drought and pluvial, the anthropogenic imprint on recent moisture trends in the Great Plains, and the possible multi-decadal regimes in the frequency of rapid-onset spring to summer flash drought over the Great Plains during the past 500- to 1000-years.The highest agricultural production in the United States occurs in the Great Plains, a region also subject to frequent drought, including the flash drought of 2012 that resulted in $30 billion in losses. Proxy tree ring and lake sediment data suggest that the instrumental record of precipitation and soil moisture may not be representative of the natural variability of severe droughts and prolonged wet intervals over the past millennium. Anthropogenic climate change may be contributing to wetter conditions in the Northern Plains and increasing dryness over the Southern Plains, a possible expression of the drying symptomatic of the expansion of the Hadley Cell and the weakening of the jet stream predicted by many climate models. These human-induced changes threaten to disrupt agriculture, energy production, and water use, and may be magnified by recurrent decadal moisture extremes witnessed in instrumental and paleoclimate records. Very few exactly dated, annual tree-ring chronologies are available from the mostly treeless Great Plains. The lack of data adds considerable uncertainty to the available reconstructions of moisture anomalies for this region. This project seeks to reduce the uncertainty by developing long tree-ring chronologies within and along the boundaries of the Great Plains to aid reconstruction of past drought and wetness in this critical agricultural region.The potential Broader Impacts (B.I.) include improvement in understanding climate processes involving drought and extreme events in the Great Plains regions that impact the highest agricultural production in the United States. Importantly, the project includes researchers and students from a regional Primarily Undergraduate Institution (PUI) which has strong ties to affected agricultural and tribal communities.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.

这项研究的总体目标是开发水分敏感的年轮年表，从古老的种群的杜松，松，红豆杉树从大平原内或附近的季节性降水和长期的土壤水分平衡，共同构成大平原干旱地图集（GPDA）的原位重建。将开发五个以0.5度分辨率跨越大平原的网格重建，包括春季和夏季的标准化降水指数（SPI），春季和夏季的降水总量以及夏季帕尔默干旱严重程度指数（PDSI）。重建将被设计为最大长度，目的是将湿度估计扩展到中世纪时期，当时气候似乎更加温暖和干燥。GPDA将用于检验有关大平原干旱和多雨的程度、大平原近期湿度趋势的人为印记以及过去500至1000年大平原春季至夏季快速干旱频率的可能数十年制度的假设。美国最高的农业生产发生在大平原，该区域也经常遭受干旱，包括2012年造成300亿美元损失的暴旱。代用树木年轮和湖泊沉积物数据表明，仪器记录的降水量和土壤湿度可能不能代表过去一千年严重干旱和长时间潮湿间隔的自然变异。人为气候变化可能导致北方平原更加湿润，南部平原更加干燥，这可能是许多气候模型预测的哈德利环流扩大和急流减弱的干燥症状的表现。这些人为引起的变化可能会破坏农业，能源生产和水资源利用，并可能被仪器和古气候记录中经常出现的十年期极端湿度放大。很少有确切的日期，每年的树木年轮年表是从大平原上几乎没有树木。数据的缺乏增加了相当大的不确定性，该地区的水分异常的可用重建。该项目旨在通过在大平原内部和沿着大平原的边界建立长期的树木年轮年表来减少不确定性，以帮助重建这一关键农业地区过去的干旱和潮湿。包括更好地理解气候过程，包括大平原地区的干旱和极端事件，这些事件影响了美国最高的农业生产。 重要的是，该项目包括来自一个地区性的初级本科院校（PUI）的研究人员和学生，该院校与受影响的农业和部落社区有着密切的联系。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知识价值和更广泛的影响审查标准进行评估来支持。