NSFGEO-NERC: Understanding Trans-Hemispheric Modes of Climate Variability: A Novel Tree-Ring Data Transect spanning the Himalaya to the Southern Ocean

NSFGEO-NERC：了解气候变化的跨半球模式：跨越喜马拉雅山到南大洋的新型树轮数据样带

• 批准号: NE/W007223/1
• 负责人: Robert Wilson
• 金额: $ 32万
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW007223%2F1
• 关键词: NSFGEO; NERC; Understanding; Trans; Hemispheric

The mechanisms that govern trans-hemispheric climate linkages and those between the tropics and higher latitudes are not well understood, especially before the Anthropogenic period. Hence there are gaps in knowledge that limit our understanding of broader-scale climate teleconnections on interannual to decadal and longer time scales. Unlike the western Americas, where symmetries and common oscillatory modes are observed due to geographic similarities between the two hemispheres, the western Pacific lacks such symmetry, and data coverage of high resolution, well-dated paleorecords is limited over much of the region. We propose to repurpose an existing tree-ring data transect spanning from the Himalaya to the Southern Ocean, based on wood samples from our archives collected from broader monsoon Asia down to southern middle latitudes. By creating a new data network that focuses on earlywood (EW) and latewood (LW) width and maximum and minimum Blue Intensity (BI), these data will be used to enhance prior climate analyses based almost entirely on the single total ring-width (RW) parameter. BI is an indirect proxy of relative wood density and has been shown to be potentially more responsive to temperature and hydroclimate than TRW alone at low cost and effort. This expanded data transect will be used to model and reconstruct key modes of atmosphere-ocean variability between the northern and southern hemispheres (NH and SH).The NSF-NERC project PIs have jointly pioneered BI and EW-LW research in the tropics and SH mid-latitudes. Proof of concept data show that BI, EW and LW parameters for several Himalayan, tropical and mid-latitude SH conifers are robustly reflective of climate variability, placing our research team in a unique position to expand our knowledge of temperature and hydroclimate variability across the region. This new suite of data will provide the opportunity to model and reconstruct key indicators of atmosphere-ocean circulation dynamics across this transect, the tropical Indo-Pacific is a key region of interest, where the El Niño-Southern Oscillation (ENSO), Intertropical Convergence Zone (ITCZ), and Indian Ocean Dipole are dominant sources of climate variability with global impact. Volcanism perturbs climate across both hemispheres, while the Southern Annular Mode or Antarctic Oscillation impacts climate towards the SH mid latitudes at the southern end of our transect. The new data coverage, parameters, analyses and reconstructions will allow us to address several outstanding research questions, including: 1. What are the climatic impacts of volcanic events in the tropics and Southern Hemisphere? 2. How have the ITCZ and ENSO varied of the past 500-1000 years as expressed across our study region? And 3. How has the Southern Annular Mode varied over the past millennium, and is it driven by tropical forcing? To understand the global response to climate requires robust, high-resolution paleoclimate data from the tropics and SH, which our proposed transect will provide.This project will lead to an improved understanding of past variability in climate-sensitive, yet data-sparse regions of the Eastern Hemisphere transect proposed herein, some of the most climatically vulnerable regions of the globe. These data will be disseminated to the broader community via the International Tree-Ring Data Bank and other venues and will be included in a future iteration of the Monsoon Asia Drought Atlas. Education will be an important component of this project as well. Data from this project will be used for instructional purposes in a Masters level class taught at Columbia University (CU) by the lead PI and an undergraduate level course at Rider University (RU) by the RU PI. RU students will participate in this project and travel between RU and CU for educational activities. Regular virtual student exchanges will take place between students from RU, CU and foreign partners.

支配跨半球气候联系的机制以及热带和高纬度地区之间的气候联系还没有得到很好的理解，特别是在人类活动时期之前。因此，知识上的差距限制了我们对年际到十年和更长时间尺度上更大尺度气候遥相关的理解。与美洲西部不同，由于两个半球之间的地理相似性，观察到对称性和共同的振荡模式，西太平洋缺乏这种对称性，高分辨率的数据覆盖面，以及过时的古记录在该地区的大部分地区是有限的。我们建议重新利用现有的树木年轮数据样带，从喜马拉雅山到南大洋，从我们的档案收集更广泛的季风亚洲到南中纬度地区的木材样本的基础上。通过创建一个新的数据网络，重点关注早材（EW）和晚材（LW）宽度以及最大和最小蓝色强度（BI），这些数据将用于增强几乎完全基于单一总环宽（RW）参数的先前气候分析。BI是相对木材密度的间接代理，并且已经被证明比TRW单独低成本和低努力对温度和水文气候的响应更快。这一扩大的数据样带将用于模拟和重建北方和南半球（北半球和南半球）之间大气-海洋变化的关键模式。NSF-NERC项目PI共同开创了热带和南半球中纬度地区的BI和EW-LW研究。概念验证数据表明，几种喜马拉雅，热带和中纬度SH针叶树的BI，EW和LW参数强烈反映了气候变化，使我们的研究团队处于独特的位置，以扩大我们对整个地区温度和水文气候变化的了解。这套新的数据将为模拟和重建该样带的大气-海洋环流动力学的关键指标提供机会，热带印度洋-太平洋是一个关键的感兴趣区域，厄尔尼诺-南方涛动（ENSO），热带辐合带（ITCZ）和印度洋偶极子是具有全球影响的气候变率的主要来源。火山活动扰动了两个半球的气候，而南半球环形模式或南极涛动影响了我们样带南端南半球中纬度地区的气候。新的数据覆盖范围，参数，分析和重建将使我们能够解决几个突出的研究问题，包括：1。热带和南半球的火山活动对气候有什么影响？2. ITCZ和ENSO在过去的500-1000年中是如何变化的？和3.在过去的一千年里，南部环形模态是如何变化的，它是由热带强迫驱动的吗？为了了解全球对气候的响应，需要强大的，高分辨率的古气候数据从热带和SH，我们建议的样带将provided.This项目将导致过去的气候敏感，但数据稀疏的地区，本文提出的东半球样带，一些气候最脆弱的地区的地球仪的变化的理解。这些数据将通过国际树轮数据库和其他渠道向更广泛的社区传播，并将纳入《亚洲季风干旱地图集》的未来版本。教育也将是该项目的重要组成部分。本项目的数据将用于指导哥伦比亚大学（CU）由首席PI教授的硕士课程和Rider大学（RU）由RU PI教授的本科课程。RU学生将参加这个项目，并在RU和CU之间旅行的教育活动。定期的虚拟学生交流将在RU，CU和外国合作伙伴的学生之间进行。

项目成果

Evaluating the dendroclimatological potential of blue intensity on multiple conifer species from Australasia

评估澳大利亚多种针叶树物种蓝色强度的树木气候潜力

• DOI: 10.5194/bg-2021-119
• 发表时间: 2021
• 作者: Wilson R

Evaluating the dendroclimatological potential of blue intensity on multiple conifer species from Tasmania and New Zealand

评估塔斯马尼亚和新西兰多种针叶树物种蓝色强度的树木气候潜力

• DOI: 10.5194/bg-18-6393-2021
• 发表时间: 2021
• 期刊: Biogeosciences
• 影响因子: 4.9
• 作者: Wilson R

Experiments of the efficacy of tree ring blue intensity as a climate proxy in central and western China

树木年轮蓝色强度作为中西部地区气候代理的有效性试验

• DOI: 10.5194/egusphere-2023-135
• 发表时间: 2023
• 作者: Zheng Y