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: 1903334
• 负责人: Joerg Schaefer
• 金额: $ 17.2万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903334&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气候系统过去自然变化的背景下评估正在进行的地球变暖，例如众所周知的小冰河时代和黑暗时代寒冷时期，中世纪和罗马温暖时期，以及在全新世早期（大约8，000至10，000年前）记录的某些地区比现在更温暖的条件。这些过去的气候异常最好是从北方半球记录的;因此，尚不清楚它们是否构成大气热量收支的全球波动，或者它们是否具有区域性质。这个问题对于理解自然气候变异性的潜在驱动因素，以及确定工业时代的变暖是否已经超过过去10，000年记录的气候变异性的包络线具有根本性的影响。该项目建立了全新世气候变化的记录，基于冰川和温度敏感的树木，在新西兰的南阿尔卑斯山-在地球的另一边从北大西洋地区。山地冰川是地球上最敏感的气候记录器之一，其时间跨度可达数十年甚至更长。全球范围内的山地冰川衰退是全球变暖的一个标志性例证。冰川地貌提供了过去冰川范围的实物证据，这项工作将对这些地貌采用最先进的宇宙成因测年技术，以确定有记录的观测期间和之前冰川变化的精确年表。这项工作结合了对温度敏感的南岛物种的树木年轮年表，提供了每年时间尺度上气候波动的连续记录。总而言之，冰川范围和树木生长的年表将被用来开发一个全面的记录，过去的温度变化在南阿尔卑斯山的比较，在北方半球的同等记录。由此产生的温度重建还将为评估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。这项工作将为下一代科学家和科学记者提供实地教育经验。古气候研究的一个目标是了解全新世自然气候变化的模式和驱动因素。轨道，百年和更短的频率上的自然气候变率的文件提供了一个上下文框架建模正在进行的和未来的变暖，由于增加大气CO2的影响。在持续变暖之前，北大西洋地区最近的主要自然气候变化是罗马暖期的变化（约公元前250年至公元400年），黑暗时代寒冷时期（~公元450年~公元950年）、中世纪暖期（~公元950年~公元1150年）和小冰期（~公元1150年~公元1850年）。这些晚全新世的温度变化记录在欧洲阿尔卑斯山的冰川长度变化的高分辨率记录，以及独立的，每年解决的树木年轮为基础的区域夏季温度重建。此外，欧洲冰川在全新世早期监测到一段冰量减少的时期，与此同时，树木线海拔较高。这两个观测结果都表明夏天比今天温暖。但目前尚不清楚这些气候特征是全球性的还是区域性的;因此，根本的机制仍然不确定。这项工作将解决这个问题，通过开发一个精确的10 Be表面暴露年代学冰碛建造的冰川在全新世在新西兰南阿尔卑斯山-在地球的另一边从欧洲阿尔卑斯山。研究人员还将通过14 C测定最近冰川消退的有机遗骸来开发全新世冰退缩的年代学。研究人员采用了一个校准良好的冰川学模型，将这些冰碛年表转换为过去两千年来冰川温度的记录。建议的冰川年表将合成一个独立的和互补的记录区域夏季温度在过去的2000年来自南岛银松环宽度。冰川和树木年轮记录将被用作基准，以调查GFDL ESM 2 M工业化前气候模拟的结果。基于这种冰川、树木和模拟方法，这项工作的目标是确定全新世气候变化是否具有全球性，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评估来支持。影响审查标准。

项目成果

Cosmogenic nuclide techniques

宇宙成因核素技术

• DOI: 10.1038/s43586-022-00096-9
• 发表时间: 2022
• 期刊: Nature reviews methods primers
• 作者: Schaefer, J.M.;Codilean, A.T.;Willenbring, J.K.;Lu, Z.-T.;Keisling, B.;Fülöp, R.-H.;Val, P.
• 通讯作者: Val, P.

Glacier response to Holocene warmth inferred from in situ ¹⁰Be and ¹⁴C bedrock analyses in Steingletscher's forefield (central Swiss Alps)

根据 Steingletscher 前场（瑞士阿尔卑斯山中部）的原位 ¹⁰Be 和 ¹⁴C 基岩分析推断冰川对全新世温暖的响应

• DOI: 10.5194/cp-18-23-2022
• 发表时间: 2022
• 期刊: Climate of the Past
• 影响因子: 4.3
• 作者: Schimmelpfennig, Irene;Schaefer, Joerg M.;Lamp, Jennifer;Godard, Vincent;Schwartz, Roseanne;Bard, Edouard;Tuna, Thibaut;Akçar, Naki;Schlüchter, Christian;Zimmerman, Susan
• 通讯作者: Zimmerman, Susan

Early Holocene cold snaps and their expression in the moraine record of the eastern European Alps

• DOI: 10.5194/cp-17-2451-2021
• 发表时间: 2021-12-02
• 期刊: CLIMATE OF THE PAST
• 影响因子: 4.3
• 作者: Braumann, Sandra M.;Schaefer, Joerg M.;Fiebig, Markus
• 通讯作者: Fiebig, Markus