P2C2: Collaborative Research:Spatiotemporal Variability of Northwestern North American Temperatures in Response to Climatic Forcing

一般而言，该奖项旨在将一种新的分析技术应用于从现有和新获得的样本档案中获取的千年尺度树轮数据，以重建与太平洋年代际涛动等气候强迫的主要模式密切相关的过去温度变率。研究人员瞄准了三个气候敏感地区，在这些地区，阿拉斯加南部的阿拉斯加湾、阿拉斯加北部的苏卡帕克和加拿大西北部(不列颠哥伦比亚省育空、艾伯塔省)的现有样本档案中都有这种长度的树轮宽度(RW)记录。最终的气候重建将与气候模型输出进行比较，以检查响应气候强迫(特别是火山)的时空模式，识别不确定性，并测试关于内部和强迫变化模式的假设。该奖项将使用蓝色强度(BI)参数为这些地点生成一套新颖的最大晚材密度(MXD)年表，该年表的成本和劳动力密集度大大低于传统的MXD技术，但保留了传统MXD技术的准确性和分辨率。在这个广阔的区域，目前存在的亚千年至千年尺度的MXD年表很少。研究人员认为，基于活的和亚化石的木材材料产生的BI年表将产生关于过去极端气候、过去温度的趋势和变化、内部太平洋变异性的时空表达以及过去1000年北美西北部外部气候强迫的细节的可靠记录。该研究项目在四个关键方面产生了广泛影响，即：第一，该项目将综合北美西北部对气候敏感的树轮记录网络，对过去的气候变化从季节内、十年到百年时间尺度进行高分辨率、高度校准的重建。随着野外温度重建的发展，这些树枝气候重建将主要使用现有的数据，这些数据将被处理，以利用新的BI技术提取新的信息。树轮数据将与模型输出和其他代理记录进行比较，并提供给建模社区。第二，该项目的科学成果将通过国家地球物理数据中心(NGDC)和国际树轮数据库(ITRDB)存档并提供给科学界。第三，研究人员将酌情与阿拉斯加的原住民群体进行接触。过去，私人投资机构通过让土著人民参与研究，与北部社区进行了广泛的互动，并计划为这个项目继续这样做。潜在的研究成果可能与当地居民相关，数据和解释将提供给相关社区(例如北极边疆生态知识合作社、http://www.taiga.net/coop/index.html).Fourth，)。该项目将支持本科生和研究生，作为伍兹霍尔海洋研究所本科生研究体验计划和伍斯特学院学生计划的一部分。本科生的支持将使他们有更早的研究经验。

Generally, this award aims to apply a novel analytical technique to a millennial-scale tree-ring data from existing and newly-obtained sample archives to yield reconstructions of past temperature variability closely linked to dominant modes of climatic forcing, such as the Pacific Decadal Oscillation (PDO). The researchers are targeting three climatically-sensitive regions where tree-ring width (RW) records of this length are available in existing sample archives from the Gulf of Alaska in southern Alaska, Sukakpak in northern Alaska, and northwestern Canada (Yukon, British Columbia, Alberta). The resulting climate reconstructions will be compared with climate model outputs to examine spatiotemporal patterns in response to climate forcing (particularly volcanoes), identify uncertainties, and test hypotheses regarding internal and forced modes of variability.This award will generate a suite of novel, maximum latewood density (MXD) chronologies for these sites using the Blue Intensity (BI) parameter, which is substantially less costly and labor intensive yet retains the accuracy and resolution of traditional MXD techniques. There are few sub-millennial to millennial scale MXD-based chronologies currently existing for this vast region. The researchers argue that the resulting BI chronologies, based on living and subfossil wood material, will yield robust records of past climatic extremes, trends and shifts in past temperature, spatiotemporal expressions of internal Pacific variability, as well as details regarding the external climate forcing over northwestern North America for the past millennium. The research project has broad impact in four key aspects, namely:First, this project will synthesize a network of climatically-sensitive tree-ring records from across northwestern North America to yield high-resolution, strongly calibrated reconstructions on past climate variability from intra-seasonal to Decadal to Centennial time scales. These dendroclimatic reconstructions will mainly be developed using existing data that will be processed to extract new information using the new BI technique, along with the development of field temperature reconstructions. Tree-ring data will be compared to model output and other proxy records and made available to the modeling community. This research will help advance a broader understanding of the long-term variability of climate over the past millennium for one of the most rapidly changing regions of the globe.Second, scientific results from the project will be archived and provided to the scientific community through the National Geophysical Data Center (NGDC) and International Tree-Ring Data Bank (ITRDB). Third, as appropriate, the researchers will engage with native groups in Alaska. In the past, the PIs have interacted extensively with northern communities by involving native peoples in research and plan to continue to do so for this project. The potential research outcomes could have relevance to native populations and the data and interpretations will be available to relevant communities (community groups, e.g. Arctic Borderlands Ecological Knowledge Cooperative, http://www.taiga.net/coop/index.html).Fourth, the project will support undergraduate and graduate students as part of the Woods Hole Oceanographic Institution Research Experience for Undergraduates (REU) program and the student program at The College of Wooster. The support of undergraduate students would allow for an early experience in research.