Collaborative Research: P2C2: Reconstructing Holocene Climate Change in the Southern Hemisphere from Southern Alps Mountain Glaciers and Tree Rings

合作研究：P2C2：从南阿尔卑斯山冰川和树木年轮重建南半球全新世气候变化

• 批准号: 1903175
• 负责人: Joellen Russell
• 金额: $ 4.72万
• 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: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903175&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Reconstructing; Holocene

A major objective of climate science is to evaluate ongoing planetary warming within the context of past natural variations of the climate system, such as the well-known Little Ice Age and Dark Ages cold periods, and Medieval and Roman warm periods, as well as warmer-than-present conditions in some regions registered during the early Holocene, about 8,000 to 10,000 years ago. These past climatic anomalies are best documented from the Northern Hemisphere; thus, it is not clear whether they constituted global fluctuations in the atmospheric heat budget or if they were regional in nature. This question has fundamental implications for understanding the underlying drivers of natural climate variability, and for determining whether industrial-age warming has yet exceeded the envelope of climate variability registered over the past 10,000 years. This project establishes the record of Holocene climate variations, based on glaciers and temperature-sensitive trees, in the Southern Alps of New Zealand - on the opposite side of the planet from the North Atlantic region. Mountain glaciers are among Earth's most sensitive climate recorders on timescales of decades and longer. Worldwide recession of mountain glaciers is an iconic illustration of global warming. Glacial landforms afford physical evidence of past glacier extent, and this effort will employ state-of-the-art cosmogenic dating techniques on those landforms to establish precise and accurate chronologies of glacier changes during and prior to the period of recorded observations. This work incorporates tree-ring chronologies of temperature-sensitive South Island species that afford continuous records of climatic fluctuations on annual timescales. Altogether, chronologies of glacier extent and tree growth will be used to develop a comprehensive record of past temperature variation in the Southern Alps for comparison to equivalent records in the Northern Hemisphere. The resultant temperature reconstruction will also provide a key metric for evaluating a suite of global climate and earth-system models developed by the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory, some of which are now being used for weather forecasting by the National Weather Service. This effort will afford field-based educational experiences for the next generation of scientists and science journalists. A goal of paleoclimate research is to understand patterns and drivers of natural climate variations during the Holocene. Documentation of natural climate variability on orbital, centennial, and shorter frequencies provides a contextual framework for modeling ongoing and future warming due to the effects of increasing atmospheric CO2. The most recent major natural climatic variations in the North Atlantic regime prior to the ongoing warming were those of the Roman Warm Period (~250 B.C. to ~A.D. 400), Dark Ages Cold Period (~A.D. 450 to ~A.D. 950), Medieval Warm Period (~A.D. 950 to ~A.D. 1150) and the Little Ice Age (~A.D. 1150 to ~A.D. 1850). These late-Holocene temperature variations are documented by highly resolved records of glacier-length variation in the European Alps, as well as independent, annually resolved tree-ring-based regional summer temperature reconstructions. In addition, European glaciers monitored a period of reduced ice extent during the early Holocene at the same time as tree-line altitudes were higher. Both observations signify summers that were warmer than those of today. But it is not yet clear whether these climate signatures were global or regional in scope; thus, the underlying mechanisms remain uncertain. This work will address this problem by developing a precise 10Be surface-exposure chronology of moraines constructed by glaciers during the Holocene in the Southern Alps of New Zealand - on the opposite side of the planet from the European Alps. The researchers will also develop chronology of Holocene ice retraction by 14C dating recently deglaciated organic remains. Investigators employ a well-calibrated glaciological model to convert these moraine chronologies into a glacier-derived record of temperature over the past two millennia. The proposed glacier chronology will be synthesized with an independent and complementary record of regional summer temperatures for the past 2000 years derived from South Island silver pine ring widths. The glacier and tree-ring records will be used as benchmarks to investigate results from the GFDL ESM2M preindustrial climate simulations. On the basis of this glacier, dendro, and modeling approach, the goal of this work is to determine whether Holocene climate variations were global or not, and therefore improve understanding of underlying drivers and the scope of natural climate variability in light of ongoing planetary warming.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.

气候科学的一个主要目标是在过去气候系统自然变化的背景下，如众所周知的小冰期和黑暗时代冷期、中世纪和罗马暖期，以及大约8 000至10 000年前全新世早期记录的一些区域比现在更暖的情况，来评估正在进行的全球变暖。这些过去的气候异常最好是从北半球记录下来的；因此，尚不清楚它们是构成了大气热量收支的全球波动，还是具有区域性性质。这个问题对于理解自然气候变异性的根本驱动因素，以及确定工业时代的变暖是否已经超过了过去10,000年来记录的气候变异性的范围，具有根本的意义。该项目建立了新西兰南阿尔卑斯山全新世气候变化的记录，该记录基于冰川和对温度敏感的树木，位于地球与北大西洋地区的另一边。山地冰川是地球上最敏感的气候记录器之一，其时间尺度为几十年或更长时间。全球范围内山地冰川的衰退是全球变暖的标志性例证。冰川地貌提供了过去冰川范围的实物证据，这项工作将在这些地貌上采用最先进的宇宙学测年技术，以建立有记录的观测期间和之前冰川变化的精确和准确的年表。这项工作纳入了对温度敏感的南岛物种的树轮年表，这些年表提供了年度时间尺度上气候波动的连续记录。总之，冰川范围和树木生长的年表将被用来建立南阿尔卑斯山过去温度变化的全面记录，以便与北半球的同等记录进行比较。由此产生的温度重建还将为评估由美国国家海洋和大气管理局地球物理流体动力学实验室开发的一套全球气候和地球系统模型提供一个关键指标，其中一些模型目前正被国家气象局用于天气预报。这一努力将为下一代科学家和科学记者提供实地教育体验。古气候研究的一个目标是了解全新世期间自然气候变化的模式和驱动因素。关于轨道、百年和更短频率的自然气候变异性的记录为模拟由于大气二氧化碳增加的影响而持续和未来的变暖提供了一个背景框架。在持续变暖之前，北大西洋地区最新的主要自然气候变化是罗马暖期(公元前250年至公元400年)、黑暗时代冷期(公元450年至公元950年)、中世纪暖期(公元950年至公元1150年)和小冰期(公元1150年至1850年)。欧洲阿尔卑斯山冰川长度变化的高分辨率记录，以及独立的、基于树轮的区域夏季温度重建，记录了这些全新世晚期的温度变化。此外，在全新世早期，欧洲冰川监测到了一段冰范围缩小的时期，同时林线高度较高。这两个观测结果都表明，夏天比今天的夏天要暖和。但目前尚不清楚这些气候信号是全球性的还是区域性的；因此，潜在的机制仍然不确定。这项工作将通过开发一份精确的10Be冰雹地表暴露年表来解决这一问题，该年表是新西兰南阿尔卑斯山全新世冰川建造的，位于地球与欧洲阿尔卑斯山的另一边。研究人员还将通过对最近冰川消融的有机遗骸进行14C测年，建立全新世冰川退缩的年表。研究人员使用了一个校准良好的冰川学模型，将这些冰川年表转换为过去两千年来冰川衍生的温度记录。拟议的冰川年表将与根据南岛银松年轮宽度得出的过去2000年区域夏季温度的独立和补充记录相结合。冰川和树木年轮记录将被用作基准，以调查GFDL ESM2M工业化前气候模拟的结果。在冰川、树枝和模型方法的基础上，这项工作的目标是确定全新世气候变化是否是全球性的，从而根据持续的全球变暖改善对潜在驱动因素和自然气候变化范围的理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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

Heinrich summers

海因里希·萨默斯

• DOI: 10.1016/j.quascirev.2022.107750
• 发表时间: 2022
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: Denton, George H.;Toucanne, Samuel;Putnam, Aaron E.;Barrell, David J.A.;Russell, Joellen L.
• 通讯作者: Russell, Joellen L.

Correspondence Among Mid‐Latitude Glacier Equilibrium Line Altitudes, Atmospheric Temperatures, and Westerly Wind Fields

中纬度冰川平衡线高度、大气温度和西风场的对应关系

• DOI: 10.1029/2022gl099897
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Audet, Alexander C.;Putnam, Aaron E.;Russell, Joellen L.;Lorrey, Andrew;Mackintosh, Andrew;Anderson, Brian;Denton, George H.
• 通讯作者: Denton, George H.

Representation of Southern Ocean Properties across Coupled Model Intercomparison Project Generations: CMIP3 to CMIP6

• DOI: 10.1175/jcli-d-19-0970.1
• 发表时间: 2020-08-01
• 期刊: JOURNAL OF CLIMATE
• 影响因子: 4.9
• 作者: Beadling, R. L.;Russell, J. L.;Pandde, Amarjiit
• 通讯作者: Pandde, Amarjiit

The Zealandia Switch: Ice age climate shifts viewed from Southern Hemisphere moraines

• DOI: 10.1016/j.quascirev.2020.106771
• 发表时间: 2021-03-12
• 期刊: QUATERNARY SCIENCE REVIEWS
• 影响因子: 4
• 作者: Denton, George H.;Putnam, Aaron E.;Strand, Peter D.
• 通讯作者: Strand, Peter D.