Maximizing the scientific application of Pandora column observations of HCHO and NO 2

作者：Prajjwal Rawat, J. H. Crawford, Katherine R. Travis, Laura Judd, Mary Angelique G. Demetillo, Lukas C. Valin, J. Szykman, Andrew Whitehill, Eric Baumann, T. F. Hanisco · 发表于：Atmospheric measurement techniques · 年份：2025 · DOI：10.5194/amt-18-2899-2025 · 被引用次数：12 · 研究领域：Atmospheric Ozone and Climate、Atmospheric and Environmental Gas Dynamics、Spectroscopy and Laser Applications

Abstract. As part of the Pandonia Global Network (PGN), Pandora spectrometers are widely deployed around the world. These ground-based remote-sensing instruments are federated such that they employ a common algorithm and data protocol for reporting on trace gas column densities and lower-atmospheric profiles using two modes based on direct-sun and sky-scan observations. To aid users in the analysis of Pandora observations, the PGN standard quality flagging procedure assigns flags to the data indicating high, medium, and low quality. This work assesses the suitability of these data quality flags for filtering data in the scientific analysis of formaldehyde (HCHO) and nitrogen dioxide (NO2), two critical precursors controlling tropospheric ozone production. Pandora data flagged as high quality assure scientifically valid data and are often more abundant for direct-sun NO2 columns. For direct-sun HCHO and for sky-scan observations of both molecules, large amounts of data flagged as low quality also appear to be valid. Upon closer inspection of the data, independent uncertainty is shown to be a better indicator of data quality than the standard quality flags. After applying a filter to independent uncertainty, Pandora data flagged as medium or low quality in both modes can be demonstrated to be scientifically useful. The utility of this filtering method is demonstrated by correlating contemporaneous but independent direct-sun and sky-scan observations. When evaluated across 15 Pa...