Retrieval of NO2 tropospheric column from ground-based FTIR measurements of direct solar radiation
M.V. Makarova1, D.V. Ionov1, H.H. Imkhasin1, A.V. Poberovskii1, A.V. Polyakov1, V.S. Kostsov1, B.K. Makarov1,2, S.C. Foka1
1Saint-Petersburg State University, St. Petersburg, Russia
2Federal state unitary enterprise “Alexandrov Research Institute of Technology”, Sosnovy Bor, Russia
Keywords: nitrogen dioxide, ground-based FTIR measurements, ground-based DOAS measurements, tropospheric column, inverse problems of atmospheric optics
Abstract
Based on the analysis of high-resolution FTIR spectra recorded at the atmospheric monitoring station of St. Petersburg State University during 2009-2022, a possibility of deriving NO2 tropospheric column from ground-based measurements of direct solar radiation in the mid-IR range is studied. The best agreement (correlation coefficient r = 0.68) with simultaneous DOAS measurements of tropospheric NO2 column at the same monitoring station is demonstrated by a retrieval strategy based on the use of the spectral range 2914.30-2914.85 cm-1 in combination with Tikhonov-Phillips regularization. It is shown that FTIR measurements make it possible to detect high levels of tropospheric NO2 at the SPbU monitoring station. Our results can be used at the FTIR stations of the NDACC network for significant expansion of the geography of tropospheric NO2 monitoring.
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