Comparison of Data of OMI Long-Term Measurements of NO2 Contents in the Stratosphere and Troposphere with the Results of Ground-Based Measurements

The results of measuring the NO2 content in vertical columns of the stratosphere and troposphere using the Ozone Monitoring Instrument (OMI) on board the EOS Aura satellite in 2004-2020 are compared with the results of ground-based measurements at stations of the Network for the Detection of Atmospheric Composition Change (NDACC), first and foremost, with the results of measurements at the Zvenigorod Scientific Station (ZSS) of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The comparison between the satellite data and the ZSS data is performed using the two products of satellite measurements: the NO2 contents in stratospheric and tropospheric columns. When comparing the OMI data with ground-based measurements at other stations, satellite values of the NO2 content in the stratospheric column are compared to values of the total content (TC) of NO2 obtained from ground-based measurements. The correspondence between the results of satellite and ground-based measurements is characterized by the magnitude of difference between them, the linear correlation coefficients, and regression coefficients. The difference has a noticeable seasonal variation. The correlation and regression coefficients depend significantly on the season. Characteristic patterns of correlation coefficient changes with latitude, as well as specific features of correlation between satellite and ground-based data in the polar and middle latitudes of the Southern Hemisphere in spring, have been revealed. For some stations, the dependence of quantitative characteristics of the correspondence between the results of satellite and ground-based measurements on cloudiness has been found. Under cloudless conditions at the ZSS, a weakening of the correlation between the satellite and ground-based values of the stratospheric NO2 content and an increase in the correlation between the values of the tropospheric NO2 content is observed. The dependence of the correspondence characteristics between the data of satellite and ground-based measurements on the level of pollution of the lower troposphere by nitrogen oxides is revealed. The correlation between the values of the tropospheric NO2 content in the vicinity of ZSS under strong pollution increases, while the correlation between the values of the stratospheric NO2 content decreases. Based on the results of the comparison of satellite and ground-based data, estimates of the upper threshold values of the tropospheric NO2 content at different stations are found. The lowest values are obtained for polar stations, and the highest value are obtained for the ZSS, which is most susceptible to anthropogenic pollution due to its proximity to the Moscow megapolis.