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.

该赠款将支持博士后研究者开发一个主要的新综合北极气候变异性气候变化的新综合，并将气候重建与气候模型模拟进行比较。该合成将建立在当前正在研究过去8000年记录的研究人员目前正在开发的代理气候记录的基础上。 NCAR社区气候系统模型（CCSM3）以及2012年计划的新模型实验的输出。该项目生成的北极气候重建将从全球范围内集成到全球的类似综合上，该计划由两者设想为IIGBP，该计划是在2012年所产生的北极气候重建，该计划是由两者集成到IIGBP，将从NCAR的社区气候系统模型（CCSM3）以及该项目的新型气候重建中汲取数据模型比较。两千年？还有？syntrace？ projects。智能优点。根据她/他的背景和职业目标，博士后科学家将在以下研究问题中进行选择：（1）从全新世热最大（HTM）到新冰川（5000至3000年前）统一的气候过渡？描述这种主要气候转变的时空模式是为了评估气候变化的程度，是海洋 - 大气循环中温度的动态重新分布的结果，而不是北极气候平均气候的变化。 （2）与世界其他地方相比，北极中的新缝线冷却是否在北极地区放大？为了了解与北极扩增相关的反馈，必须评估北极冷却的大小。 （3）从HTM到新缝线的冷却纬度梯度与由CCSM3模拟在Syntrace实验中模拟的前进强迫驱动的冷却梯度相比如何？量化此梯度为数据模型比较提供了一个直接的目标。 （4）是否从数十年到几个世纪的北极范围内重建气候变化的幅度和模式，与CCSM3 Syntrace Syntrace实验中模拟的可变性一致？为了确定气候变化可以合理地归因于已知的大气 - 海洋循环模式的自然变异性，必须分析代理数据和模型模拟的主要变异性模式。 （5）在环境变化的机理模型中，可用气候系统模拟的输出可以用作边界条件，从而近似驱动代理起诉者的过程？开发新的？逆向模型？为了预测气候变化如何驱动代理指标，例如冰川范围，降水量的氧相同位素值以及北极湖的主要生产力是为了避免基于经典回归基于气候重建方法的主要假设。该项目将有助于了解气候变异性，这是社会面临的关键挑战。结果将为验证气候模型提供基准，并提高其准确模拟非线性变化的能力。改善未来气候预测的模型将有助于气候变化和变化？美国气候变化科学计划的主要计划要素。该提案的全部资金要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气候科学家跨学科团队的一部分接受第一手培训。他/他将了解研究北极和全球气候变化的广泛基于数据和模型的方法。在2011年秋冬期间，PS将在瑞士伯尔尼的国际项目办公室工作，在那里PI安排为客座科学家，在这里他们将很适合与国际集团一起参与代理记录的综合。 PS还将与科罗拉多州博尔德市NCAR的气候建模者一起工作，他/他将学会分析气候模型模拟的输出。在NAU，PS将集成到PI研究计划的完整广度中，该计划包括主动的分析实验室和现场研究计划。还将鼓励PS帮助定期教授本科和研究生课程，以提高其教学能力。