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

世界一个地区的气候变化往往与世界另一个地区的气候变化有关。 例如，在数百年的时间尺度上，粗略尺度的代用指标表明，地球仪的北大西洋区域的温度可能会变化，而南大西洋区域的温度变化的符号则相反。 这种“两极跷跷板”的模型调用了通过大气或海洋的长距离信息传输（遥相关）。 拟议的工作将使用格陵兰岛和南极洲的冰芯记录来调查海洋和大气遥相关在所谓的“海因里希事件”期间耦合两个半球的相对作用-冰山大量排放到北大西洋，在上一个冰河时代反复发生。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，这些时间尺度比气象站的观测记录要长得多。 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期提供支持。 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STEM推广到当地中学生和教师培训计划。 这将导致一系列关于古气候的维基百科条目。 作为一个附带的好处，它将改善格陵兰冰芯的年代学研究。 这将使两极之间的古气候记录更加同步，并促进过去气候研究的进展。拟议的工作将产生格陵兰（GISP 2）冰芯甲烷，分子氮的15 N/14 N比和空气含量的高分辨率，高精度记录，时间为14-51 ka。研究一些重要的古气候问题，特别关注海因里希的天文台。研究工作的总体目标是：（1）探测Heinrich事件对格陵兰气候的影响，并利用这些事件相对于观测到的南极快速变暖的时间来研究这些事件期间的半球间气候耦合模式是通过大气还是海洋遥相关;（2）实现GISP 2和WAIS分水岭冰芯的极间甲烷同步，分辨率达到前所未有的百年尺度，并应用于研究半球间气候遥相关和冰芯测年。(3)通过将氮同位素数据与来自甲烷同步的独立三角洲年龄估计相结合，提供迄今为止最准确的格陵兰温度重建;（4）提高对空气含量作为冰盖高程代理的理解，并调查文献中先前未描述的Dansgaard-Oeschger事件期间千年尺度空气含量变化的起源。该项目利用最近厘米级WAIS Divide甲烷记录产生的独特科学可能性，以增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