Inter-Hemispheric Climate Teleconnections in response to Massive Iceberg Discharge in the North Atlantic

世界某一地区的气候变化往往与世界另一地区的气候变化有关。例如，在数百年的时间尺度上，粗尺度代用品表明，全球北大西洋地区的温度可能发生变化，而南大西洋地区的温度则以相反的符号变化。这种“两极跷跷板”的模型唤起了信息通过大气或海洋的远距离传输（远距连接）。拟议中的工作将利用格陵兰岛和南极洲的冰芯记录，调查在所谓的“海因里希事件”期间，海洋和大气远距连接在两个半球耦合中的相对作用。“海因里希事件”是指在上一个冰河时期反复发生的大量冰山向北大西洋排放。这项工作将帮助气候科学家了解发生在时间尺度上的动态变化，而时间尺度要比气象站的观测记录长得多。该项目还将有助于STEM劳动力的发展。它将为早期职业科学家在其职业生涯的形成阶段提供支持。它将为一名或多名本科实验室技术人员提供支持，并通过其他来源支持本科生参与研究。它将包括对当地中学生的STEM推广和教师培训计划。这将导致维基百科上出现一系列关于古气候的条目。作为附带的好处，它将改进待研究的格陵兰冰芯的年代学。这将使两极之间的古气候记录更加同步，并促进对过去气候的研究取得进展。该工作将生成格陵兰岛（GISP2）冰芯甲烷、15N/14N分子氮比和空气含量在14-51 ka之前的高分辨率、高精度记录，以研究一系列重要的古气候问题，并特别关注海因里希冰川。提出的工作有四个总体目标：(1)探测海因里希事件对格陵兰气候的影响，并利用这些事件相对于已观测到的南极快速变暖的时间来研究这些事件期间半球间气候耦合模式是通过大气还是海洋遥相关；(2)以前所未有的百年尺度实现GISP2和WAIS分裂冰芯的极间甲烷同步，并应用于研究半球间气候遥相关和冰芯测年；(3)将氮同位素数据与甲烷同步的独立三角洲年龄估算相结合，提供迄今为止最精确的格陵兰岛温度重建；(4)提高对空气含量作为冰盖海拔的代用物的认识，并研究Dansgaard-Oeschger事件期间千年尺度空气含量变化的起源，这些变化在以前的文献中没有描述过。该项目利用最近厘米尺度的WAIS分裂甲烷记录所产生的独特科学可能性，以加强对格陵兰冰芯和极地间气候连通性的解释

Changes in the climate of one part of the world can often be associated with changes in another part of the world. For example, on time scales of hundreds of years, coarse scale proxies indicate that the temperature of the North Atlantic region of the globe may change while the temperature of the South Atlantic region changes with the opposite sign. Models of this "bipolar seesaw" invoke the long-distance transmission (teleconnection) of information through the atmosphere or the ocean. The proposed work will use ice core records from Greenland and Antarctica to investigate the relative roles of oceanic and atmospheric teleconnections in coupling both hemispheres during so-called "Heinrich events" - massive discharges of icebergs into the North Atlantic that happed repeatedly during the last ice age. The work will help climate scientists understand dynamical changes that occur on times scales that are much longer than observational records from weather stations. The project will also contribute to development of the STEM workforce. It will provide support for an early-career scientist during the formative years of his career. It will provide support for one or more undergraduate laboratory technicians and entrain undergraduates, supported through other sources, into the research. It will include STEM outreach to local middle school students and a teacher training program. It will result in a series of Wikipedia entries concerning paleoclimate. As an ancillary benefit, it will improve the chronology of the Greenland ice core to be studied. This will allow greater synchronization of paleoclimate records between the two poles and facilitate progress in the study of past climates.The proposed work will generate high-resolution, high-precision records of Greenland (GISP2) ice core methane, 15N/14N ratio of molecular nitrogen, and air content for the period of 14-51 ka before present, to investigate a number of important paleoclimatic questions with a special focus on Heinrich stadials. The proposed work is organized under four overarching goals: (1) to detect the impact of Heinrich events on Greenland climate, and use the timing of these events relative to observed rapid Antarctic warming to investigate whether the mode of interhemispheric climate coupling during these events is via an atmospheric or an oceanic teleconnection; (2) to achieve interpolar methane synchronization of the GISP2 and WAIS Divide ice cores at unprecedented centennial-scale resolution, with applications in studying interhemispheric climate teleconnections and ice core dating.; (3) to provide the most accurate Greenland temperature reconstruction to date by combining nitrogen isotope data with independent delta-age estimates derived from the methane synchronization; and (4) to improve understanding of air content as a proxy for ice sheet elevation, and investigate origin of millennial-scale air content variations during Dansgaard-Oeschger events not previously described in the literature. This project exploits the unique scientific possibilities arising from the recent centimeter-scale WAIS Divide methane record to enhance the interpretation of Greenland ice cores and inter-polar climate connectivity