Experimentelle Studien der reaktiven Halogenchemie in der polaren Troposphäre

拟议研究活动的目的是，根据多轴差分光学吸收光谱法对卤素自由基的测量，对反应性卤素化合物在极地边界层和自由对流层化学中的作用进行实验研究。近年来，越来越多的证据表明，卤素的光化学可能在全球范围内的对流层中发挥重要作用。对流层中存在活性卤素的后果包括臭氧的破坏、重要化学族平衡的变化、有毒化合物沉积的增加以及对全球气候的潜在影响。然而，对流层中卤素的测量仍然非常稀少。因此，进一步了解反应性卤素参与的过程对于更好地理解对流层光化学是至关重要的。将通过在各种平台上对对流层卤素化合物进行MAX-DOAS测量来研究这些过程：在极地沿海地区和北极海漂流浮标上进行的陆基长期测量将提供关于活性卤素的日变化和季节变化及其在两个极地半球的源和汇的独特信息。将参加在南极洲活性卤素潜在来源地区的实地活动，以调查导致这些卤素释放到大气中的机制。分析这些数据的目的是促进更好地了解活性卤素对大气系统的影响。

The objective of the proposed research activity is the experimental investigation of the role of reactive halogen compounds in the chemistry of the polar boundary layer and the free troposphere based on measurements of halogen radicals by Multi-Axis Differential Optical Absorption Spectroscopy (MAXDOAS). Growing evidence has emerged in recent years that the photochemistry of halogens might play an important role in the troposphere on a global scale. The consequences of the presence of reactive halogens in the troposphere are ranging from the destruction of ozone over changes in the balance of important chemical families and the increased deposition of toxic compounds to a potential impact on global climate. However, measurements of halogens in the troposphere are still very sparse. It is therefore of vital importance for a better understanding of tropospheric photochemistry to obtain further insight into the processes reactive halogens are involved in. These processes will be studied by performing MAX-DOAS measurements of tropospheric halogen compounds on various platforms: Ground-based long-term measurements in polar coastal areas and on drifting buoys in the Arctic sea will provide unique information on the diurnal and seasonal variability of reactive halogens and on their sources and sinks in both polar hemispheres. The participation in a field campaign at potential source regions of reactive halogens in Antarctica will be performed to investigate the mechanisms leading to their release into the atmosphere. The analysis of these data has the aim of contributing to a better understanding of the impact of reactive halogens on the atmospheric system.