Flade Isblink Ice Core Chemistry Measurements

The role of aerosols in climate forcing is significant but poorly understood. The primary goals of this project are to (1) develop unique high-time-resolution, millennial-scale records of biomass burning, dust, volcanic, industrial pollution, and sea salt aerosols for two ice core sites inside the Arctic polar dome and (2) use new and leveraged general circulation models (GCM) and other modeling to interpret these and similar ice core records from outside the polar dome to better understand source regions and transport pathways of aerosols to different regions of the Arctic and their climatic and environmental impacts. Measurements of >35 elemental and chemical components of these aerosols will be made at high depth resolution (>50 measurements per year) in archived ice cores from two lower elevation sites on opposite sides of the Arctic: a 430 m core collected by the University of Copenhagen in 2006 from Flade Isblink ice cap in far northeastern Greenland and a 724 m core collected by the Alfred Wegener Institute (AWI) in 1999 to 2001 from Akademii Nauk ice cap in the Russian Arctic. The measurements build on recently published findings from similar analyses in shallower ice cores. Flade Isblink will provide a >3500 year record of aerosols in the lower troposphere in the North Atlantic sector of the Arctic Ocean ? a region particularly sensitive to changes in Arctic sea ice ? while Akademii Nauk will provide a > 3000 year record of past aerosols in northern Eurasia, as well as dust and pollutants from eastern Asia. By extending instrumental records to recent centuries and millennia, this new generation of ice core records, coupled with model simulations, will transform understanding of recent and late Holocene changes in hemispheric atmospheric circulation, aerosol transport across the polar front, and feedbacks between climate and aerosols.

气溶胶（aerosols）在气候强迫（climate forcing）中的作用举足轻重，但目前仍缺乏充分的科学认知。本项目的核心目标有二：其一，为北极极地穹顶（Arctic polar dome）内的两处冰芯（ice core）站点，建立兼具高时间分辨率与千年尺度的生物质燃烧（biomass burning）、粉尘（dust）、火山气溶胶（volcanic）、工业污染（industrial pollution）及海盐气溶胶（sea salt aerosols）记录；其二，依托新开发与已整合的通用环流模式（General Circulation Models, GCM）及其他模拟手段，解读上述冰芯记录与极地穹顶外的同类冰芯数据，以厘清气溶胶的源区、向北极不同区域的传输路径，及其对气候与环境的影响。研究团队将以高深度分辨率（每年完成超50次测量），对北极两侧两处低海拔站点的归档冰芯中气溶胶的35余种元素与化学成分开展检测。这两处站点分别为：哥本哈根大学（University of Copenhagen）于2006年在格陵兰极东北部弗拉德冰盖（Flade Isblink）采集的430米冰芯，以及阿尔弗雷德·魏格纳研究所（Alfred Wegener Institute, AWI）于1999至2001年在俄罗斯北极地区科学院冰盖（Akademii Nauk ice cap）采集的724米冰芯。本项测量工作基于此前针对浅层冰芯开展类似分析所发表的最新研究成果。弗拉德冰盖将提供北冰洋北大西洋扇区低层大气中逾3500年的气溶胶记录——该区域对北极海冰（Arctic sea ice）变化尤为敏感——而科学院冰盖则将提供北欧亚大陆过去3000余年的气溶胶记录，以及源自东亚的粉尘与污染物。通过将仪器观测记录延伸至近百年乃至数千年尺度，这批全新的冰芯记录结合模式模拟结果，将革新学界对半球尺度大气环流、跨极锋（polar front）气溶胶传输，以及气候与气溶胶间反馈机制的近期和全新世（Holocene）晚期变化的认知。