Transfer Function for Photochemically Produced Chemical Species in Greenland Snow, Firn and Ice

主要研究人员将开发过去大气光化学的记录，主要是过氧化氢（H2O2），来自格陵兰岛的雪、雪和冰。这些重建的大气记录将为过去区域和全球羟基自由基（OH）水平的大气光化学模拟提供重要的数据约束，以评估过去几个世纪大气OH的表观变化。氧化能力决定了许多微量化学物质和温室气体在大气中的寿命。首席研究员将评估和验证一个以H2O2为模型化合物的空气-雪交换模型，以及在过去几百年中区分H2O2浓度的统计显著变化所需的时空平均程度。他们的方法包括：1)分析和综合冰芯数据，2)分析先前的大气和地表雪数据，以及3)模拟空气-雪交换过程和大气化学，以解释雪、雪和冰中的浓度。先前对建模的一个限制是缺乏用于模型测试的共同登记的次年分辨率冰芯数据。首席研究人员目前正在对格陵兰北部四个地点120-150米深的岩心进行持续分析，这将为建模提供出色的数据，并将继续对Summit新的100米岩心进行分析。另一个限制因素是缺乏适合推断雪和化学物质沉积和积累模式的全年记录。首脑会议的1997- 1998年冬季上空监测方案应扩展基于物理的模式，并将大气和地表雪浓度与南极数据库联系起来，以便进行模式校准、测试和评估。模拟将继续进行基于物理的空气-雪交换H2O2和大气化学模型的框架，这些模型是主要研究人员利用南极洲两个地点的数据和Summit的初步数据开发和测试的。这个建议是多余的。该报告是在1998年4月1日北极自然科学（ANS）截止日期前提交的。1998财政年度余下的ANS预算用于资助一些ANS标准赠款，并作出了一项行政决定，将4月1日提交的所有提案保留为1999财政年度的资金。此外，大部分建议在1998年8月5日至6日举行的sciex小组会议上进行了讨论。由于美国海军研究办公室（Office of Naval Research， ONR）的同行行程繁忙，我们直到9月23日才开会讨论哪些提案将转移到ONR的资金中。我们当时的首要任务是在1999财年预算的不确定性得到解决之前完成削减。由于联合首席研究员从亚利桑那大学转到沙漠研究所，与此同时，我告诉贝尔斯博士，我建议为该提案提供资金，因此进一步推迟了处理该奖项的时间。

AbstractOPP-98-13311The Principal Investigators will develop a record of past atmospheric photochemistry, primarily hydrogen peroxide (H2O2), from Greenland snow, firn, and ice. These reconstructed atmospheric records will provide an important data constraint for atmospheric photochemical modeling of past regional and global hydroxyl radical (OH) levels to evaluate the apparent change in atmospheric OH over the past few centuries. Oxidation capacity determines the atmospheric lifetime of many trace chemical species and greenhouse gases. The Principal Investigators will evaluate and validate a model of air-snow exchange using H2O2 as a model compound and the degree of spatial and temporal averaging needed to distinguish statistically significant changes in the concentrations of H2O2 over the past few hundred years. Their approach includes: 1) analysis and synthesis of ice-core data, 2) analysis of prior atmospheric and surface snow data, and 3) modeling of air-snow exchange processes and atmospheric chemistry for interpretation of concentrations in snow, firn, and ice. One previous constraint on the modeling was the lack of availability of co-registered, sub-annual resolution ice-core data for model testing. The Principal Investigators are currently doing continuous analysis on 120-150 m deep cores from four sites in northern Greenland, which will provide excellent data for modeling and will continue these analyses on a new 100-m core from Summit. Another constraint was the lack of availability of year-around records suitable for inferring the deposition and accumulation patterns of snow and chemical species. The 1997-98 winter-over monitoring program at Summit should expand the physically-based model and relate atmospheric and surface snow concentrations to the South Pole data base for model calibration, testing and evaluation. Modeling will continue the framework of physically- based models of air-snow exchange of H2O2 and atmospheric chemistry that the Principal Investigators have developed and tested using data from two sites in Antarctica and preliminary data from Summit. DIARY NOTEThis proposal is overage. It was submitted on April 1 for the April 1, 1998 Arctic Natural Sciences (ANS) deadline. The remaining FY1998 ANS budget was committed to funding a few ANS standard grants and an executive decision was made to hold all of the proposals that were submitted for April 1 for FY1999 funds. In addition, most of the proposals were discussed at the SCICEX panel held on August 5-6, 1998. Due to the heavy travel schedule of our Office of Naval Research (ONR) counterpart, we were unable to meet to discuss which proposals would be transferred to ONR funding until September 23. Our highest priority then was to complete the declinations before they became overage while the uncertainties with the FY1999 budget were being addressed. Further delays in processing this award were due to the co-Principal Investigator transferring from the University of Arizona to Desert Research Institute at the same time that I told Dr. Bales that I was recommending funding of this the proposal.