Nitrogen Oxides in the Arctic Marine Boundary Layer during the Polar Sunrise Experiment-2000

北极春季大气中卤素化合物的光化学反应导致边界层臭氧耗竭、汞向北极生态系统的沉积以及卤素介导的有机化合物分解。然而，这些过程的关键方面还没有得到充分的了解。极地日出实验-2000 （PSE-2000）旨在提高对春季边界层卤素化学和地表雪作为光化学活性化合物来源和汇的作用的理解。作为PSE-2000项目的一部分，这里建议测量和分析氮氧化物混合比。NO， NO2和NOy将在加拿大Nunavut Alert附近的PSE-2000站点进行测定，使用NOx的梯度测量和N02光解速率常数和光谱光化通量的辅助测量。提议的二氧化氮测量将与溴化物和其他化合物的测量一起使用，由合作研究人员研究这些反应对臭氧耗竭化学的重要性。对NO-NO2光稳定态的分析将进一步揭示BrO + NO2 = BrONO2反应和其他NOx-sink反应的重要性。测量NOx的垂直梯度和分析日出后NOx和NOy的预期日循环将用于研究雪表面作为光化学活性氮氧化物化合物的源和汇的作用。

Honrath abstract Photochemical reactions of halogen compounds in the Arctic springtime atmosphere cause depletion of boundary-layer ozone, deposition of mercury to the arctic ecosystem, and halogen-mediated decomposition of organic compounds. However, key aspects of these processes are inadequately understood. The Polar Sunrise Experiment-2000 (PSE-2000) is designed to improve understanding of springtime boundary layer halogen chemistry and the role of surface snow as a source and sink of photochemically active compounds. Measurements and analyses of nitrogen oxides mixing ratios are proposed here as part of the PSE-2000 project. NO, NO2, and NOy will be determined at the PSE-2000 site near Alert, Nunavut, Canada, with gradient measurements of NOx and ancillary measurements of the N02 photodissociation rate constant and spectral actinic flux. The proposed N02 measurements will be used with measurements of BrO and other compounds by collaborating researchers to investigate the importance of these reactions to O3-depletion chemistry. Analyses of the NO-NO2 photostationary state will provide further insight into the importance of the BrO + NO2 = BrONO2 reaction and other NOx-sink reactions. Measurements of the vertical gradient of NOx and analysis of expected post-sunrise diurnal cycles in NOx and NOy will be used to investigate the role of the snow surface as a source and sink for photochemically active nitrogen oxide compounds.