The TOPAS (Tikhonov regularised Ozone Profile retrievAl with SCIATRAN) algorithm to retrieve vertical profiles of ozone from space-borne observations in nadir-viewing geometry has been developed at the Institute of Environmental Physics (IUP) of the University of Bremen and applied to the TROPOspheric Monitoring Instrument (TROPOMI) L1B spectral data version 2. Spectral data between 270 and 329 nm are used for the retrieval. A recalibration of the measured radiances is done using ozone profiles from MLS/Aura. Studies with synthetic spectra show that individual profiles in the stratosphere can be retrieved with an uncertainty of about 10 %. In the troposphere, the retrieval errors are larger depending on the a priori profile used. The vertical resolution above 18 km is about 6–10 km, and it degrades to 15–25 km below. The vertical resolution in the troposphere is strongly dependent on the solar zenith angle (SZA). The ozone profiles retrieved from TROPOMI with the TOPAS algorithm were validated using data from ozonesondes and stratospheric ozone lidars. Above 18 km, the comparison with sondes shows excellent agreement within less than ±5 % for all latitudes. The standard deviation of mean differences is about 10 %. Below 18 km, the relative mean deviation in the tropics and northern latitudes is still quite good, remaining within ±20 %. At southern latitudes, larger differences of up to +40 % occur between 10 and 15 km. The standard deviation is about 50 % between 7–18 km and about 25 % below 7 km. The validation of stratospheric ozone profiles with ground-based lidar measurements also shows very good agreement. The relative mean deviation is below ±5 % between 18–45 km, with a standard deviation of 10 %. TOPAS retrieval results for 1 d of TROPOMI observations were compared to ozone profiles from the Microwave Limb Sounder (MLS) on the Aura satellite and the Ozone Mapping and Profiler Suite Limb Profiler (OMPS-LP). The relative mean difference was found to be largely below ±5 % between 20–50 km, except at very high latitudes.

中文翻译：

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从紫外线范围内的最低点 TROPOMI 测量中检索臭氧剖面

不来梅大学环境物理研究所 (IUP) 开发了 TOPAS（Tikhonov 使用 SCIATRAN 正则化臭氧剖面检索）算法，用于从天底观测几何中的星载观测中检索臭氧的垂直剖面，并应用于对流层监测仪器 (TROPOMI) L1B 光谱数据版本 2。270 和 329 nm 之间的光谱数据用于检索。使用 MLS/Aura 的臭氧剖面对测量的辐射进行重新校准。对合成光谱的研究表明，可以在大约 10% 的不确定性下检索平流层中的单个剖面。在对流层，根据使用的先验剖面，反演误差更大。18 公里以上的垂直分辨率约为 6 至 10 公里，低于 15 至 25 公里。对流层的垂直分辨率很大程度上取决于太阳天顶角 (SZA)。使用来自臭氧探空仪和平流层臭氧激光雷达的数据验证了使用 TOPAS 算法从 TROPOMI 检索的臭氧剖面。超过 18 公里，与探空仪的比较在不到±5  % 适用于所有纬度。平均差异的标准偏差约为 10%。在18公里以下，热带和北纬的相对平均偏差仍然很好，保持在±20  %以内。在南纬地区， 在 10 到 15 公里之间出现高达+40 % 的更大差异。标准偏差在 7-18 公里之间约为 50%，在 7 公里以下约为 25%。使用地面激光雷达测量对平流层臭氧剖面的验证也显示出非常好的一致性。相对平均偏差低于±5 % 介于 18-45 公里之间，标准偏差为 10 %。将 1 天 TROPOMI 观测的 TOPAS 检索结果与来自 Aura 卫星上的微波肢体探测仪 (MLS) 以及臭氧测绘和剖面仪套件肢体剖面仪 (OMPS-LP) 的臭氧剖面进行比较。发现相对平均差异 在 20-50 公里之间大大低于±5 %，除了在非常高的纬度。