Record of Atmospheric Photochemistry in Firn at South Pole

约瑟夫·麦康奈尔这项拟议的工作涉及通过测量和解释南极站雪和雪中的过氧化氢、甲醛和硝酸浓度，来发展大约200年来大气氧化能力的历史。主要目标是建立过去大气光化学的记录，次要目标是评估解决过去200年这些物种浓度在统计上的重大变化所需的空间或时间平均程度。拟议的方法包括全年对空气和近地表积雪进行采样，夏季对雪坑和降雪核心进行采样和分析，并对空气-雪化学进行模拟，以解释降雪中观测到的浓度。南极站是这项工作的理想之选，因为极端寒冷使化学成分相对简单，NOAA气候模拟和诊断实验室提供了高质量的气象和化学数据，并且站的常年占用使全年采样成为可能。南半球夏季将在积雪桩田周围的两个雪坑中进行密集采样(用于堆积观测)。为了保持对地层和化学层位和标志物的时间控制，靠近桩油田是很重要的。该模拟计划将在首席调查员在南极和格陵兰中部早期工作期间开发和测试的过氧化氢的空气-雪地交换物理模型的框架上进行扩展。

9903744Joseph McConnellThis proposed work concerns the development of a history of the oxidation capacity of the atmosphere over approximately the past two hundred years by measuring and interpreting the hydrogen peroxide, formaldehyde, and nitric acid concentrations in the snow and firn at South Pole station. The primary goal is to develop a record of past atmospheric photochemistry, with a secondary goal of evaluating the degree of spatial or temporal averaging necessary to resolve statistically significant changes in the concentration of these species over the past 200 years. The proposed approach involves year-round sampling of air and near-surface snow, summer sampling and analysis of snow pits and firn cores, and modeling the air-snow chemistry in order to interpret the observed concentrations in the firn. South Pole station is ideal for this work because the extreme cold makes the chemistry relatively simple, the NOAA Climate Modeling and Diagnostics Laboratory provides a context of high quality meteorological and chemical data, and the year-round occupation of the station makes year-round sampling possible.Intensive sampling during the austral summer will be done in two snow pits around the perimeter of the snow stake field (for accumulation observations). Proximity to the stake field is important in order to maintain time control for stratigraphic and chemical horizons and markers. The modeling program will expand on the framework of physically based models of the air-snow exchange of hydrogen peroxide developed and tested by the principal investigator during earlier work at South Pole and in central Greenland.***