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

莫斯利-汤普森俄亥俄州立大学OPP-03-52527智力优势：首席研究人员将在美国国家航空航天局-美国国家科学基金会北极区域气候评估计划(PARCA)的支持下，分析自1995年以来在格陵兰岛收集的五个多世纪冰芯整个长度上的主要阴离子和阳离子，并以低于年度的分辨率进行分析。很少有格陵兰冰芯被离子色谱学连续分析，特别是用来量化火山来源的硫酸盐沉积历史。大多数格陵兰火山历史都是基于电导测量的，电导测量是过量硫酸盐(EXS)的替代，而不是直接测量。PARCA岩芯提供了一个无与伦比的机会，可以将每年解析的格陵兰冰芯EXS历史的数量增加近一倍，这些历史揭示了过去两八个世纪向大气中零星注入火山气溶胶的情况。特别令人感兴趣的是洪堡和图努岩心，它们将提供由IC分别从格陵兰西北部(~812年记录)和格陵兰东北部(~500年记录)确定的第一批年度分辨EXS历史。格陵兰冰芯的EXS历史主要反映了来自北半球和热带喷发的输入，对于估计：1)火山气溶胶在平流层中的零星注入，造成自然气候强迫机制，以及2)化石燃料(即煤炭)燃烧产生的硫酸盐气溶胶背景浓度缓慢上升，造成人为气候强迫机制。目前正在进行的研究试图区分自然强迫机制和人类活动的贡献，这需要了解平流层硫酸盐气溶胶负荷的历史以及由此引起的大气光学厚度的变化。极地冰盖提供了这种信息的最佳档案，但基于亚年度分辨率的连续化学分析的良好日期记录是有限的。首席调查员将从格陵兰的五个PARCA岩芯提取的EXS通量历史将补充现有的记录，并改进过去800年来北半球平流层硫酸盐负荷的冰芯指数的质量和细节。更广泛的影响：改进的“冰核衍生”火山气溶胶记录将对探索火山爆发和气候变化之间的关系的人有价值。分析将由一名博士生进行，其结果将构成该学生博士论文的基础。这些结果将广泛传播给那些寻求替代气候历史的人。科学家以及政策制定者和利益攸关方继续使用冰芯分析以及冰川面积和体积测量的结果。2002年4月，第107届大会第二次会议就全球变暖问题对2002年能源立法进行了讨论，主要调查人员的冰芯得出的气候历史和冰川消退的结果被纳入其中。ICE核心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考察项目和实验室分析。这个团体积极投身于教育事业。2002年，媒体宣传活动在100多篇与国家科学基金会资助的乞力马扎罗项目有关的报纸文章中重点介绍了冰核研究。这种曝光已经扩展到电视(CNN、国家地理学会)和广播(BBC世界服务等)。观众。所描述的细节证实，俄亥俄州立大学古气候冰核心研究小组坚定地致力于并积极参与促进发现和理解，同时促进各级的教学、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.