A Postdoctoral Scientist to Synthesize Proxy Records of Arctic Holocene Climate

博士后科学家合成北极全新世气候的代理记录

• 批准号: 1107869
• 负责人: Darrell Kaufman
• 金额: $ 20.1万
• 依托单位: Northern Arizona University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1107869&HistoricalAwards=false
• 关键词: Postdoctoral; Scientist; Synthesize; Proxy; Records

This grant will support a post-doctoral investigator to develop a major new synthesis of proxy climate records of Holocene climate variability from across the Arctic, and compare the climate reconstruction with climate model simulations. The synthesis will build on proxy climate records currently being developed by teams of researchers looking at the past 8000 years of records. The data-model comparison will draw from newly available transient climate simulations by NCAR?s Community Climate System Model (CCSM3), and from the output of new model experiments planned for 2012. The Arctic climate reconstructions generated by this project will be integrated into similar syntheses from across the globe, as envisioned by two on-going international efforts led by the IGBP-Past Global Changes (PAGES) program ? the ?Two Millennia? and the ?SynTraCE? projects.Intellectual Merit. Depending on her/his background and career goals, the postdoctoral scientist will choose among the following research questions: (1) Was the climate transition from the Holocene thermal maximum (HTM) to the Neoglacial (5000 to 3000 years ago) uniform across the Arctic? Describing the spatial-temporal pattern of this major climate transition is necessary to assess the extent to which the climatic shift was the result of a dynamical redistribution of temperature by ocean-atmosphere circulation versus a shift in the mean state of climate across the Arctic. (2) Was Neoglacial cooling amplified in the Arctic compared with elsewhere around the world? Assessing the magnitude of cooling in the Arctic is necessary to understand the feedbacks associated with arctic amplification. (3) How does the latitudinal gradient of cooling from the HTM to the Neoglacial compare with the gradient of cooling driven by precessional forcing as simulated by CCSM3 in the SynTraCE experiment? Quantifying this gradient provides a straightforward target for a data-model comparison. (4) Are the magnitude and pattern of climate variability that are reconstructed from proxy records on timescales of decades to centuries from across the Arctic consistent with the variability simulated in CCSM3 SynTraCE experiment? Analyzing the principal modes of variability in both the proxy data and the model simulation is necessary to determine the extent to which climatic changes can reasonably be attributed to natural variability of known modes of atmospheric-ocean circulation. (5) In what ways can the output of available climate system simulations be used as boundary conditions in mechanistic models of environmental change that approximate the processes that drive the proxy indictors? Developing new ?inverse-proxy models? to predict how climate change drives proxy indicators such as glacier extent, oxygen-isotope values of precipitation, and primary productivity of Arctic lakes is necessary to avoid major assumptions that underlie classical regression-based approaches to climate reconstructions.Broader Impact. This project will contribute to understanding climatic variability, a key challenge facing society. The results will provide benchmarks for validating climate models and for improving their ability to accurately simulate nonlinear change. Improving models for future climate projections will contribute to the ?Climate Variability and Change? major program element of the US Climate Change Science Program. The entire funding request for this proposal is to support a postdoctoral scientist (PS). This early-career scientist will receive first- hand training as part of an international, interdisciplinary team of climate scientists. S/he will learn about a broad range of both data and model-based approaches to studying Arctic and global climate change. During the fall/winter of 2011, the PS will work at the PAGES International Project Office in Bern Switzerland, where the PI is scheduled as a Guest Scientist and where they will be well situated to engage an international group in a synthesis of proxy records. The PS will also work with climate modelers at NCAR in Boulder, Colorado where s/he will learn to analyze the output of climate model simulations. At NAU, the PS will be integrated into the full breadth of the PI?s research program, which includes an active analytical laboratory and field research program. The PS also will be encouraged to help regularly teach undergraduate and graduate courses to improve his/her teaching skills.

这笔赠款将支持一名博士后研究员开发一个新的主要综合资料，综合整个北极地区全新世气候变化的代用气候记录，并将气候重建与气候模型模拟进行比较。综合将建立在代用气候记录的基础上，这些记录目前正在由研究人员小组研究过去8000年的记录。数据模型的比较将借鉴新提供的瞬态气候模拟NCAR？的社区气候系统模型（CCSM 3），并从2012年计划的新模型实验的输出。由该项目产生的北极气候重建将被整合到来自地球仪的类似综合中，正如IGBP-过去全球变化（PAGES）计划领导的两项正在进行的国际努力所设想的那样。的？两千年？还有SynTraCE？项目。智力优势。根据她/他的背景和职业目标，博士后科学家将选择以下研究问题：（1）从全新世热最大（HTM）到新冰期（5000至3000年前）的气候转变在整个北极是均匀的吗？有必要描述这一重大气候转变的时空模式，以评估气候变化在多大程度上是海洋-大气环流造成的温度动态再分布的结果，而不是整个北极气候平均状态的变化。(2)与世界其他地方相比，北极地区的新冰期冷却是否被放大了？评估北极冷却的程度对于了解与北极放大相关的反馈是必要的。(3)从HTM到新冰期的冷却的纬度梯度与SynTraCE实验中CCSM 3模拟的岁差强迫驱动的冷却梯度相比如何？量化这个梯度为数据模型比较提供了一个直接的目标。(4)从整个北极几十年到几百年的时间尺度上的代用记录重建的气候变率的大小和模式是否与CCSM 3 SynTraCE实验中模拟的变率一致？分析代用数据和模式模拟中的主要变率模式对于确定气候变化在多大程度上可以合理地归因于已知的大气-海洋环流模式的自然变率是必要的。(5)现有气候系统模拟的结果可以何种方式用作环境变化机制模型的边界条件，以近似驱动代用指标的过程？开发新？反向代理模型预测气候变化如何驱动冰川范围、降水的氧同位素值和北极湖泊的初级生产力等代用指标是必要的，以避免基于经典回归方法的气候重建的主要假设。该项目将有助于了解气候变化，这是社会面临的一个关键挑战。这些结果将为验证气候模型和提高其准确模拟非线性变化的能力提供基准。改进未来气候预测模型将有助于？气候变率和变化？这是美国气候变化科学计划的主要项目。该提案的全部资金请求是支持博士后科学家（PS）。这位早期职业科学家将作为国际跨学科气候科学家团队的一员接受第一手培训。S/他将了解广泛的数据和基于模型的方法来研究北极和全球气候变化。在2011年秋/冬期间，PS将在瑞士伯尔尼的PAGES国际项目办公室工作，PI将作为客座科学家在那里工作，他们将很好地参与国际小组对代理记录的综合。PS还将与位于科罗拉多博尔德的NCAR的气候建模人员合作，在那里他/她将学习分析气候模型模拟的输出。在NAU，PS将被整合到PI的全方位？的研究计划，其中包括一个积极的分析实验室和实地研究计划。还将鼓励PS定期帮助教授本科生和研究生课程，以提高他/她的教学技能。