Reconstructing Late Holocene Volcanic Aerosol Fluxes from Greenland Ice Cores Collected by the PARCA Project

摘要莫斯利-汤普森俄亥俄州立大学OPP-03- 52527知识价值：主要研究人员将在NASA-NSF的支持下，沿着自1995年以来在格陵兰岛收集的五个多世纪冰芯的整个长度，以亚年度分辨率分析主要阴离子和阳离子。PARCA（北极区域气候评估计划）项目。少数格陵兰冰芯已连续分析，在亚年度分辨率的离子色谱法（IC），专门量化的历史火山衍生硫酸盐沉积。大多数格陵兰火山的历史是基于电导测量，作为替代，但不是直接测量，过量硫酸盐（EXS）。PARCA核心提供了一个无与伦比的机会，使EXS的年度解析格陵兰冰芯历史数量增加近一倍，这些冰芯历史揭示了过去两到八个世纪火山气溶胶向大气中的零星注入。特别令人感兴趣的是洪堡和图努核心，将提供第一个每年解决的EXS历史确定的IC从西北格陵兰岛（~812年的记录）和东北格陵兰岛（~500年的记录），分别。来自格陵兰冰芯的EXS历史主要反映了来自北方半球和热带火山爆发的输入，对于估计以下情况至关重要：1）平流层中火山气溶胶的零星注入，创造了自然气候强迫机制; 2）化石燃料燃烧产生的硫酸盐气溶胶背景浓度缓慢上升（即，煤炭），创造一个人为的气候强迫机制。目前正在进行的研究试图区分自然强迫机制的作用和人类活动的作用，需要了解平流层硫酸盐气溶胶负荷的历史以及由此造成的大气光学厚度的变化。极地冰盖提供了这方面信息的最佳档案，但基于连续化学分析的年代久远的记录是有限的。EXS通量的历史，首席调查员将从五个格陵兰PARCA核心提取将补充现有的记录，并提高质量和细节的冰芯指数的北方半球平流层硫酸盐负荷在过去800 years.Broader Impacts：改进的“冰芯派生”火山气溶胶记录将是有价值的，探索爆发性火山活动和气候变化之间的关系。分析将由博士进行。学生和结果将构成学生的博士论文的基础。研究结果将广泛传播给那些寻求替代气候历史的人。科学家以及决策者和利益攸关方继续使用冰芯分析结果以及冰川面积和体积测量结果。主要研究人员的冰芯得出的气候历史和冰川退缩的结果被列入第107届国会的第二次会议，2002年4月，全球变暖的讨论，以2002年的能源立法。冰核研究小组包括博士后研究员，研究生和本科生，他们定期参加他们的实地项目和实验室分析。这个团体积极从事教育工作。2002年，媒体宣传包括在与国家科学基金会资助的基利曼哈罗项目有关的100多篇报纸文章中突出介绍冰芯研究。这种接触已经延伸到电视（CNN，国家地理学会）和广播（BBC世界服务等）。受众描述的细节证实，俄亥俄州国家古气候冰芯研究小组是坚定地致力于并积极参与推进发现和理解，同时促进各级教学，培训和学习。

ABSTRACTMoseley-ThompsonOhio State UniversityOPP-03-52527Intellectual merit: The Principal Investigators will analyze the major anions and cations at sub-annual resolution along the entire lengths of five multi-century ice cores collected since 1995 in Greenland under the auspices of the NASA-NSF PARCA (Program for Arctic Regional Climate Assessment) Project. Few Greenland ice cores have been analyzed continuously at sub-annual resolution by ion chromatography (IC) specifically to quantify the history of volcanically-derived sulfate deposition. Most Greenland volcanic histories are based on conductance measurements that serve as a proxy for, but not a direct measure of, excess sulfate (EXS). The PARCA cores offer an unparalleled opportunity to nearly double the number of annually-resolved Greenland ice core histories of EXS that reveal the sporadic injection of volcanic aerosols into the atmosphere over the last two to eight centuries. Of particular interest are the Humboldt and Tunu cores that will provide the first annually resolved EXS histories determined by IC from northwest Greenland (~812-year record) and northeast Greenland (~500 year record), respectively. The EXS histories from Greenland ice cores, reflecting primarily the input from Northern Hemisphere and tropical eruptions are critical for estimating: 1) the sporadic injection of volcanic aerosols in the stratosphere, creating a natural climate forcing mechanism and 2) the slowly rising background concentrations of sulfate aerosols from the combustion of fossil fuels (i.e., coal), creating an anthropogenic climate forcing mechanism. Ongoing studies that seek to differentiate the contributions of natural forcing mechanisms from those attributable to human activities require knowledge of the history of stratospheric sulfate aerosol loading and the resulting changes in atmospheric optical depth. The polar ice sheets provide the best archive of this information, but well-dated records based upon continuous chemical analyses at sub-annual resolution are limited. The EXS flux histories that the Principal Investigators will extract from the five Greenland PARCA cores will complement existing records and improve the quality and detail of the ice core index of Northern Hemisphere stratospheric sulfate loading over the last 800 years.Broader Impacts: The improved 'ice core-derived' volcanic aerosol records will be valuable to those exploring the relationship between explosive volcanism and climate variability. The analyses will be conducted by a Ph.D. student and the results will constitute the basis for the student's doctoral dissertation. The results will be disseminated broadly to those seeking proxy climate histories. The results from the ice core analyses, as well as the glacier area and volume measurements, continue to be used, by scientists as well as policy makers and stakeholders. The Principal Investigators' ice core-derived climate histories and glacier retreat results were included in the 107th Congress' second session, April, 2002, for global warming discussions to the 2002 energy legislation. The ice core research group includes postdoctoral fellows, graduate students and undergraduates who regularly participate in both their field programs and the laboratory analyses. This group is actively engaged in education. In 2002, media outreach included highlights of the ice core research in more than 100 newspaper articles associated with the NSF-funded Kilimanjaro project. This exposure has extended to television (CNN, National Geographic Society) and radio (BBC World Service, etc.) audiences. The details described confirm that the Ohio State paleoclimate ice core research group is strongly committed to and actively engaged in advancing discovery and understanding while promoting teaching, training and learning at all levels.