Analysis of satellite measurements of halogen oxides in the Antarctic: source regions, transport and comparison to model simulations

海冰是南极洲大气海盐的主要来源。这一最新发现引发了对极地冰芯记录的古气候解释范式的改变。此外，从盐冰表面和盐气溶胶中释放的反应性气相卤素对对流层化学具有重要意义。极性对流层中活性溴的存在往往导致边界层臭氧完全耗竭，并导致其他微量物质如汞和生物产生的二甲基硫化物（DMS）的快速氧化。后者的氧化产物甲烷磺酸（MSA）和冰芯记录的海盐浓度已被用作推断过去海冰范围信息的代理。我们建议在一个联合项目中研究海冰表面盐气溶胶的产生、大气盐的运输、卤素的释放以及对对流层成分的影响。本文介绍了该项目的一部分：对流层大气BrO的遥感及源区和输送模式的分析。从遥感数据中分析海冰参数，开发海冰气溶胶模型，从诺伊迈尔站气溶胶过滤器测量结果以及现有冰芯和雪坑记录中研究主要离子，是汉堡大学联合提议的一部分。气溶胶传输和卤素化学的拉格朗日模型是MPI美因茨一个平行提案的一部分。拟议的联合项目包含在国际极地年核心项目“空气-冰-化学相互作用”中。

Sea ice is a major source of atmospheric sea salt in Antarctica. This recent finding triggered a change in paradigm for the paleoclimatic interpretation of polar ice core records. Moreover, the release of reactive gas-phase halogens from the salty ice surface and of salt aerosol is of major importance for the tropospheric chemistry. The presence of reactive bromine in the polar troposphere causes the often complete depletion of ozone in the boundary layer, and a fast oxidation of other trace species such as mercury and the biologically produced dimethyl sulfide (DMS). An oxidation product of the latter, methanesulfonic acid (MSA), and sea salt concentration from ice core records have been used as proxies to infer information about the past sea ice extent. We propose to investigate the processes related to the salt aerosol generation on the sea ice surface, the atmospheric salt transport, the halogen release, and the impact on the tropospheric composition in a joint project. Here we describe one part of this project: the remote sensing of tropospheric BrO and the analysis of source regions and transport patterns. The analysis of the sea ice parameters from remote sensing data, the development of a sea ice aerosol model and the investigation of the major ions from Neumayer station aerosol filter measurements as well as from existing ice core and snow pit records is part of a joint proposal by the University of Hamburg. The lagrangian modeling of aerosol transport and halogen chemistry is part of a parallel proposal from the MPI Mainz. The proposed joint project is embedded in the International Polar Year IPY core project "Air Ice Chemical Interactions (AICI-IPY)".