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

摘要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尽，汞沉积到北极生态系统，以及卤素介导的有机化合物分解。然而，对这些过程的关键方面了解不足。2000年极地日出实验(PSE-2000)旨在增进对春季边界层卤素化学以及地面雪作为光化学活性化合物的源和汇的作用的了解。作为PSE-2000项目的一部分，提出了氮氧化物混合比的测量和分析。NO、NO2和NOY将在加拿大努纳武特Alert附近的PSE-2000站点通过NOx的梯度测量以及N02的光解离速率常数和光谱光化通量的辅助测量来确定。建议的NO2测量将与BrO和其他化合物的测量一起由合作研究人员使用，以调查这些反应对臭氧耗尽化学的重要性。对NO-NO2光稳定状态的分析将进一步深入了解BrO+NO2=BrONO2反应和其他NOx-Sink反应的重要性。将利用对氮氧化物垂直梯度的测量和对日出后氮氧化物和氮氧化物的预期日循环的分析来调查雪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.