Polyakov, A., Y. Virolainen, G. Nerobelov, Y. Timofeyev, and A. Solomatnikova, Total ozone measurements using IKFS-2 spectrometer aboard MeteorM N2 satellite in 2019–2020, International Journal of Remote Sensing, 42:22, 8709-8733, 2021. doi: 10.1080/01431161.2021.1985741
Ozone is one of the key atmospheric trace gases that protects life on Earth from harmful solar ultraviolet radiation. The importance of ozone and its influence on various atmospheric processes led to the creation of a global ozone monitoring system. Satellite remote sensing methods make a significant contribution to the analysis of spatial distribution and temporal evolution of ozone content and its anomalies. We have presented a global (60° S – 90° N) total ozone column (TOC) data product derived using the IKFS-2 (Infrared Fourier Spectrometer) instrument aboard the Meteor-M N2 satellite in 2019– 2020. The IKFS-2 measures outgoing thermal radiation in 5–15 µm (660–2000 cm−1) spectral range with an un-apodized spectral resolution of 0.4 cm−1.
The retrieval technique is based on the artificial neural network (ANN) algorithm and the method of principal components. For the ANN training, we used the level 2 TOC measurements by the OMI instrument aboard the Aura satellite, thus solving the problem of calibrating the IKFS-2 TOC data product. The uncertainty estimated for IKFS-2 TOC measurements equals 10 DU (~3%). We compared IKFS-2 TOC data with ground-based measurements at 14 observational sites in the Northern Hemisphere equipped with the Dobson and Brewer spectrometers. For spatial mismatch of 70 km and temporal mismatch of 1 h, we observed the mean bias between IKFS-2 and ground-based (direct solar measurements) TOC datasets of −1.46% with a standard deviation of 2.57%.
We demonstrated that global distribution fields of IKFS-2 TOCs are consistent with OMI measurements and ECMWF ERA5 reanalysis data. In general, for seasonal means, IKFS-2 underestimates OMI TOCs by 0.1–1.0%, and ERA5 TOCs by 1.8–3.1%, depending on the season. We analysed IKFS2 TOC retrievals in 2018/2019 versus 2019/2020 Arctic winters. Differences in TOCs resulting from differences in stratospheric dynamic for two winter-spring seasons are well captured by IKFS-2. In 2020 relative to 2019, the averaged (50–90° N) deficit in TOCs comprises 72 DU (17%), 68 DU (16%), 84 DU (20%), and 70 DU (17%) for January, February, March, and April, respectively. Dataset presented is the first data product of continuous TOC measurements derived using publicly available IKFS-2 level 1b data. Further, we plan to obtain, analyze, and validate IKFS-2 TOCs for an extended period of measurements (2015–2020).