An analysis is presented for both ground- and satellite-based retrievals of total column ozone and nitrogen dioxide levels from the Washington, D.C., and Baltimore, Maryland, metropolitan area during the NASA-sponsored July 2011 campaign of Deriving Information on Surface COnditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ). Satellite retrievals of total column ozone and nitrogen dioxide from the Ozone Monitoring Instrument (OMI) on the Aura satellite are used, while Pandora spectrometers provide total column ozone and nitrogen dioxide amounts from the ground. We found that OMI and Pandora agree well (residuals within ±25 % for nitrogen dioxide, and ±4.5 % for ozone) for a majority of coincident observations during July 2011. Comparisons with surface nitrogen dioxide from a Teledyne API 200 EU NOx Analyzer showed nitrogen dioxide diurnal variability that was consistent with measurements by Pandora. However, the wide OMI field of view, clouds, and aerosols affected retrievals on certain days, resulting in differences between Pandora and OMI of up to ±65 % for total column nitrogen dioxide, and ±23 % for total column ozone. As expected, significant cloud cover (cloud fraction >0.2) was the most important parameter affecting comparisons of ozone retrievals; however, small, passing cumulus clouds that do not coincide with a high (>0.2) cloud fraction, or low aerosol layers which cause significant backscatter near the ground affected the comparisons of total column nitrogen dioxide retrievals. Our results will impact post-processing satellite retrieval algorithms and quality control procedures.

中文翻译：

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2011 年 DISCOVER-AQ 期间当地气象和气溶胶对美国马里兰州 OMI 和潘多拉光谱仪的臭氧和二氧化氮反演的影响

在美国宇航局赞助的 2011 年 7 月从柱子获取表面条件信息的活动期间，对华盛顿特区和马里兰州巴尔的摩大都市区的地面和卫星总柱臭氧和二氧化氮水平反演进行了分析与空气质量相关的垂直解析观测 (DISCOVER-AQ)。使用来自 Aura 卫星上的臭氧监测仪器 (OMI) 的卫星检索总柱状臭氧和二氧化氮，而潘多拉光谱仪提供来自地面的总柱状臭氧和二氧化氮量。我们发现 OMI 和 Pandora 在 2011 年 7 月期间的大多数重合观测中非常一致（二氧化氮的残差在 ±25% 以内，臭氧的残差在 ±4.5% 以内）。与来自 Teledyne API 200 EU 氮氧化物分析仪的表面二氧化氮的比较显示二氧化氮的昼夜变化与 Pandora 的测量结果一致。然而，宽 OMI 视野、云层和气溶胶在某些日子影响了检索，导致 Pandora 和 OMI 之间的差异高达柱状二氧化氮的 ±65% 和柱状臭氧的 ±23%。正如预期的那样，显着的云量覆盖（云量 >0.2）是影响臭氧反演比较的最重要参数；然而，与高 (>0.2) 云比例不一致的小积云或低气溶胶层会在地面附近引起显着的反向散射，影响了总柱状二氧化氮回收的比较。