Laboratory Studies of Halogen Heterogeneous Chemistry on Aerosols

A9302348本研究的目的是调查平流层二氧化氮(NO2)对臭氧化学和丰度的影响。研究人员将使用430-450 nm波长范围内的暮光吸收光谱测量北半球两个高纬度地点的NO2柱密度，其中NO2具有明显的吸收特征。其中一个地点(挪威斯瓦尔巴群岛，北纬78度)预计比另一个(阿拉斯加费尔班克斯，北纬65度)更频繁地进入极地涡旋。测量将在连续的基础上进行，为在扰动和未扰动的平流层条件下的NO2丰度提供基线。这套测量将使这些研究人员能够研究两个地点之间NO2气候学的差异，并将NO2的丰度与平流层臭氧含量、温度和环流联系起来。将使用辐射传输模拟，包括球面几何形状和在云层和气溶胶存在时的折射的影响，来构建合成光谱，使它们能够研究所反演的NO2丰度对云和气溶胶效应的敏感性，以及反演NO2垂直剖面的可行性。

A9302348 Knut The aim of this research is to investigate the role of stratospheric nitrogen dioxide (NO2) on the ozone chemistry and abundance. The researchers will measure NO2 column densities at two high-latitude sites in the northern hemisphere using twilight absorption spectroscopy in the wavelength range 430-450 nm where NO2 has appreciable absorption features. One of these sites (Svalbard, Norway, 78 degrees N) is expected to be inside the polar vortex more frequently than the other (Fairbanks, Alaska, 65 degrees N). The measurements will be conducted on a continuous basis providing a baseline for NO2 abundance under perturbed as well as unperturbed stratospheric conditions. This set of measurements will allow these researchers to study differences in NO2 climatology between the two sites and relate the NO2 abundance to stratospheric ozone content, temperature, and circulation. Radiative transfer modeling including the effects of spherical geometry and refraction in the presence of cloud and aerosol layers will be used to construct synthetic spectra that will allow them to study the sensitivity of the retrieved NO2 abundance to cloud and aerosol effects as well as the feasibility of retrieving NO2 vertical profiles.