极地海洋边界层活性卤氧自由基时空分布遥测和源汇机制研究

Reactive halogen oxides radicals are known to play key roles in the troposphere oxidation capacity and circulation of materials and energy especially in polar regions. Researches on the crucial photochemical processes of reactive halogen oxides are the advancing front and core of understanding the atmospheric chemistry and global climate change. However, because of the active chemical property and low background concentration with short lifespan, as well as complex influences, it is hard to revert the process by off-line detecting methods. So there are many crucial mechanisms which are still unclear. Here we plan to carry out the high resolution optical remote sensing observations on troposphere reactive halogen oxides in polar marine boundary layer based on multi-platform. From these measurements, continues and real time variation of reactive halogen oxides column densities and distributions will be derived. Combining with the environment factors, the storage form and influence factors will be analyzed by modeling analysis. The source, sink and the release mechanisms will be discussed, and the environment influence on troposphere oxidation capacity and ecosystem will be evaluated. Finally, this project will help to understand the chemical process of reactive halogens in polar marine boundary layer and complete the key parameters of the modeling calculation, as well as establish the foundation of recognizing the mechanisms of atmospheric oxidation capacity in polar boundary layer.

活性卤氧自由基是影响极地对流层大气氧化性和物质能量循环的关键物质，对其关键化学过程的研究是认识极地乃至全球大气化学和气候环境变化的重要前沿和核心内容。然而，由于活性卤氧自由基具有活性强、浓度低、寿命短等特点，并且影响因素复杂，无法通过离线检测的方法还原其光化学过程，因此该过程中的一些关键机制仍然存在许多问题尚不明晰。本项目针对极地海洋边界层活性卤氧自由基的产生机制和化学过程中的关键科学问题，拟通过多平台高分辨的光学遥测技术更加清晰地描述极地地区对流层卤素氧化物的浓度水平和时空分布；结合环境要素，通过模型计算分析卤素物质的储库形式并揭示其反应机制，阐明影响极地边界层卤氧自由基产生的控制因素,评估活性卤素物质对极地对流层大气氧化性和生态环境的潜在影响。项目的开展将深化对极地边界层活性卤素物质化学过程的认识，完善模式模型的关键参数，为揭示极地边界层大气氧化性的变化过程提供依据。

本项目针对极地边界层活性卤素氧化物的时空分布和源汇机制问题，构建了紫外-可见双通道差分吸收光谱系统，并在西南极菲尔德斯半岛和北极新奥尔松地区开展了长期的高分辨探测。获得了极地边界层BrO、IO和气溶胶等的垂直分布，结合气团轨迹和大气化学模型分析了春季典型卤素氧化物爆发过程中卤素氧化物、臭氧和气态汞浓度的同步变化机制，评估了不同来源的海盐气溶胶释放的溴对春季大气氧化性的影响。同时，为评价气候变化的影响，本项目针对近年来春季平流层臭氧的变化情况进行了研究，反演了2017-2020年西南极半岛和北极新奥尔松地区臭氧柱浓度的变化，分析了极地温度垂直梯度和极地涡旋对臭氧损耗的影响。相关结果为进一步评估气候变化和环境影响提供了依据。