The response of forest ecosystems to changing climate conditions is studied by many researchers. In this work, the relationships between variations in the residual gas content in discs of coniferous and deciduous trees growing in and around Tomsk (southeast of Western Siberia) and the North Atlantic Oscillation (NAO) are analyzed. We have found (1) a significant correlation between the air temperature in Tomsk region and the NAO index; (2) coherent fluctuations in the chronologies of gas components of deciduous tree discs and in the air temperature during the growing season around a 4-year cycle; (3) the correlation coefficients of the NAO index with the chronologies of CO2 (CO2 + H2O) and the ring width of the six (of eight) tree discs. A conclusion is drawn that the North Atlantic Oscillation can affect the life activity of some Siberian tree species (on a 4-year time scale). The results can be used in studies of biospheric and atmospheric processes with the aim of considering the effects of remote sources of air pressure variations on forest ecosystems.

Сопоставление данных спутниковых измерений с результатами измерений с помощью других средств – важнейшая и необходимая составляющая валидации спутниковых данных. В настоящей работе сопоставлены результаты спектрометрических измерений содержания NO2в атмосфере с помощью спутникового прибора OMI(Ozone Monitoring Instrument) в 2004–2020 гг. с данными наземных сумеречных зенитных измерений на 14 станциях сети по обнаружению изменений состава атмосферы (Network for the Detection of Atmospheric Composition Change– NDACC). Получены широтные распределения содержания NO2 и характеристик сопоставления: разности содержаний, коэффициентов корреляции и линейной регрессии между спутниковыми и наземными данными. Предложены критерии поверки межгодовых и долговременных изменений содержания NO2по данным OMIна основе результатов наземных измерений. Выявлены широтные – полушарные и региональные – особенности соответствия между спутниковыми и наземными данными. Получена существенно новая информация о зависимости характеристик сопоставления от уровня загрязнения нижней тропосферы окислами азота, а также временного масштаба вариаций NO2: межсуточного, сезонного и межгодового. Результаты будут полезны при анализе изменчивости NO2по данным OMI. Comparison of results of satellite measurements by results of independent measurements is an esencial and necessary component of validation of satellite data, justifying their use for scientific and practical tasks. The work compares the results of spectrometric measurements of the NO2content in the atmosphere by the Ozone Monitoring Instrument (OMI) in 2004–2020 with the results of ground-based twilight zenith measurements at 14 stations of the Network for the Detection of Atmospheric Composition Change (NDACC). Latitudinal distributions of quantitative characteristics of the comparison have been obtained, including the NO2contents, their differences, and correlation and linear regression coefficients between the satellite and ground-based data. Criteria for validation of interannual and long-term changes in NO2derived from the OMI data with the help of ground-based measurements are proposed. The latitudinal – hemispheric and regional – features of the correspondence between the satellite and ground-based data have been revealed. Significantly new results have been obtained on the dependence of the comparison characteristics on the level of pollution of the lower troposphere with nitrogen oxides and on the time scale of NO2variations: day-to-day, seasonal and interannual. The results will be useful in analysis of NO2variability based on OMI data. The continuation of this work may be a comparison of the results of the analysis of interannual variations and long-term NO2trends obtained on the basis of the OMI and ground-based measurement data.

— Gases desorbed by the vacuum method from the tree rings of discs of deciduous trees are measured. The content of residual gases vacuum-desorbed from tree rings is analyzed with an optoacoustic gas analyzer with a tunable CO 2 laser. The chronologies of residual CO 2 and (CO 2 + H 2 O) of some deciduous trees growing near the city of Tomsk (Western Siberia) have been derived. All the chronologies are cyclic with pronounced 2–4-year cycles. A correlation was found between the content of gases and summer temperatures and precipitation. We believe that the annual distribution of residual gases in the discs reflects the pattern of annual release of the gases from the stems of the deciduous trees into the atmosphere.

The results of an analysis of long-term trends and interannual variations of the NO2 content in the atmosphere according to measurements with the Ozone Monitoring Instrument (OMI) aboard the EOS Aura satellite in 2004–2020 are compared to the results of a similar analysis of the NO2 content derived from independent spectrometric twilight NO2 measurements by zenith-scattered solar radiation at stations of the Network for the Detection of Atmospheric Composition Change (NDACC). According to both data, seasonally dependent estimates of linear NO2 trends and variations of the NO2 content under the influence of an 11-year cycle of solar activity and large-scale circulation factors such as the Arctic and Antarctic Oscillations, variations in ocean surface temperature in the Niño 3.4 zone, and the quasi-biennial oscillation in zonal wind in the equatorial stratosphere have been obtained. In general, a good qualitative and, in some cases, quantitative correspondence between estimates of interannual variations of NO2 has been obtained. For interannual variations of stratospheric NO2, the correspondence between estimates based on satellite and ground-based data on average for all stations is not bad, but the correspondence between trend estimates is noticeably worse. The best correspondence between the analysis results has been obtained for the Zvenigorod station. For stratospheric NO2, it was noted in 80–90

The paper presents analysis of intra-centennial (inter-decadal and multidecadal) variations of the length of day (LOD) and some oceanic parameters such as sea surface temperature (SST) and sea level (SL). Methods of multivariate regression analysis and correlation analysis are used. Results of the regression analysis show a spatially coherent response of SST to LOD variations on the multidecadal time scale. The earlier response is peculiar to the north and tropical Atlantic where the multidecadal SST variations are approximately opposite to the LOD variations. In the most remaining parts of the oceans, except especially in the Nino 3.4 region of the equatorial east Pacific, the multidecadal SST variations are generally lagged relative to the antiphase variations of the LOD. Smoothing of SST averaged over different areas and of the global mean SL shows that the intra-annual variations include inter-decadal, 20–30-year, multidecadal, 60–70-year, components that correspond to similar oscillation components in the LOD. The most striking correspondence of the two components is observed between the LOD and SST averaged over the Nino 3.4 region. Generally, there are significant correlations of the intra-centennial variations on the averaged and smoothed SST series and global mean SL with the LOD variations. We propose that angular momentum exchange processes involving oceanic circulation and interactions between the Earth’s core and the mantle play probably a part in the observed relationships of intra-centennial variations in oceanic parameters with variations in the LOD.

The results of measuring the NO 2 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 NO 2 contents in stratospheric and tropospheric columns. When comparing the OMI data with ground-based measurements at other stations, satellite values of the NO 2 content in the stratospheric column are compared to values of the total content (TC) of NO 2 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 NO 2 content and an increase in the correlation between the values of the tropospheric NO 2 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 NO 2 content in the vicinity of ZSS under strong pollution increases, while the correlation between the values of the stratospheric NO 2 content decreases. Based on the results of the comparison of satellite and ground-based data, estimates of the upper threshold values of the tropospheric NO 2 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.

Measurements of gases desorbed by the vacuum method from the disc ring wood of deciduous trees were carried out. The analysis of gases was performed using a photoacoustic gas-analyzer with a tunable CO2 laser. The chronologies of residual CO2 and (CO2+H2O) gases of some trees that grew in and around Tomsk (West Siberia) have been obtained. Correlation coefficients of chronologies with temperatures and precipitations for the vegetation period are determined. All the chronologies have cycles with period of 2-4 years. We suppose that the distribution of the residual gases in the discs reflects the annual release of the gases from the stems of the deciduous trees into the atmosphere.

We present the most significant results of Russian scientists in the field of atmospheric ozone research for 2019–2022 and examine observations of tropospheric ozone, its distribution and variability on the territory of the Russian Federation, its relation with atmospheric parameters, modeling of formation processes, and its impact on public health. The state of stratospheric ozone over Russia, modeling of processes in the ozonosphere, and methods and instruments being developed are also analyzed. The review is a part of Russia’s national report on meteorology and atmospheric sciences, which was prepared for the International Association of Meteorology and Atmospheric Sciences (IAMAS). It has been reviewed and approved at the 28th General Assembly of the International Union of Geodesy and Geophysics (IUGG).

Results of measurements of NO2 contents in vertical columns of the stratosphere and troposphere using the Ozone Monitoring Instrument aboard the EOS–Aura satellite in 2004–2020 are compared to results of ground-based measurements at stations of the Network for the Detection of Atmospheric Composition Change (NDACC), first of all, to results of measurements at the Zvenigorod Scientific Station (ZSS) of the A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences. The comparison of satellite data to the ZSS data is done using the both products of satellite measurements—the stratospheric and tropospheric column NO2 contents. When comparing the data of OMI and ground-based measurements at other stations, satellite values of the NO2 content in the stratospheric column are compared to values of the total column NO2 content obtained in ground-based measurements. Correspondence between the results of satellite and ground-based measurements is characterized by the magnitude of the difference between them, linear correlation coefficients and regression coefficients. The difference has a noticeable seasonal variation. Correlation and regression coefficients depend significantly on the season. Characteristic patterns of correlation coefficient changes with latitude as well as 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 the quantitative characteristics of the correspondence between the results of satellite and ground-based measurements on cloudiness has been revealed. Under cloudless conditions at the ZSS, a weakening of the correlation between 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 noted. The dependence of the correspondence characteristics between the data of satellite and ground-based measurements on the level of pollution of the lower troposphere with nitrogen oxides has been revealed. The correlation between the values of the tropospheric NO2 content in the vicinity of the 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 is obtained. The lowest values have been obtained for polar stations, and the highest value has been obtained for the ZSS which is most susceptible to anthropogenic pollution due to its proximity to the Moscow megapolis.

The review contains the most significant results of the work of Russian scientists in the field of atmospheric ozone research performed in 2019–2022. It considers observations of tropospheric ozone, its distribution and variability in the territory of the Russian Federation, the relationship with atmospheric parameters, modeling of education processes and the impact on public health. The state of stratospheric ozone over the region, modeling of processes in the ozonosphere, developed methods and instruments were also analyzed. The review is part of Russia’s national report on meteorology and atmospheric sciences, which was prepared for the International Association for Meteorology and Atmospheric Sciences (IAMAS). The report was reviewed and approved at the XXVIII General Assembly of the International Geodetic and Geophysical Union (IUGG).

Results of measurements of the tropospheric and stratospheric NO2 columns with the TROPOMI (Tropospheric Monitoring Instrument) aboard the Copernicus Sentinel-5P satellite in 2018–2020 are compared with the results of ground-based measurements at the Zvenigorod Scientific Station (ZSS) of A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The correspondence between the satellite and ground-based measurements is characterized by the difference between them, the linear correlation coefficients, and the regression coefficients. The dependences of these parameters on the season, cloud conditions, and the height of the atmospheric boundary layer are derived.

The CO 2 content in tree wood and the radial increment of trees can change under the impact of ground fires. The study of discs of larches survived the fire of 1908 after the explosion of the space body in the Podkamennaya Tunguska region revealed a number of features in the behavior of absorbed CO 2 and (CO 2 + H 2 O) in the larch wood. The photoacoustic analysis of vacuum-desorbed samples from tree rings shows a long-term annual accumulation of CO 2 and (CO 2 + H 2 O) in tree stems after 1908. A change in CO 2 release cycling in the postcatastrophic period is ascertained. A change in variation cycling is also noted in the tree ring chronologies. According to the analysis of the correlation coefficients, the specific behavior of the larch ring width chronologies in this region is most likely due to variations in solar activity.

Results of long-term measurements and an analysis of the temporal variability of the total contents (TC) of O3 and NO2 at the Kislovodsk High-Altitude Scientific Station (KHASS) and the Zvenigorod Scientific Station (ZSS) of the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, are presented. At the KHASS, ozone measurements have been conducted since 1989 by direct and zenith-scattered ultraviolet solar radiation. The total content of NO2 was measured at the KHASS by direct solar radiation in the visible wavelength range in the morning and evening from 1981 to 2008. At the ZSS, NO2 measurements have been conducted since 1990 by zenith-scattered visible solar radiation during morning and evening twilights. The long-term variability of measurement data are analyzed using the multivariate linear regression method. Annual and seasonally dependent estimates of the linear trends of O3 and NO2 have been obtained. A common feature of the long-term trends in the TCs of O3 at the KHASS and NO2 at the ZSS and KHASS is the significant trends in the winter–spring season. The NO2 trends at the two stations are negative, and the trend at the KHASS is stronger than at the ZSS. The O3 trend at the KHASS changes its sign from positive to negative around the 2000s. For both species, estimates have been obtained for variations in their total contents associated with external (solar activity) and circulation factors.

Описываются методы и обсуждаются результаты многолетних измерений общего содержания NO2 и О3 на Звенигородской и Кисловодской высокогорной научных станциях Института физики атмосферы им. А.М. Обухова РАН. Получены годовые и сезонно зависимые оценки долговременных трендов и межгодовых вариаций примесей под действием циркуляционных факторов и колебаний уровня солнечной активности. Выявлены различия и общие особенности временной эволюции NO2 и О3 на станциях. Отмечена важная роль атмосферной циркуляции в многолетних и межгодовых изменениях содержания примесей. Полученные оценки линейных трендов сопоставлены с трендами общего содержания NO2 и О3 в других регионах. Изменения содержания NO2 под действием 11-летнего солнечного цикла сопоставлены с результатами численного моделирования.

Linear trends in the total, tropospheric, and stratospheric column NO2 contents obtained from satellite measurements using the Ozone Monitoring Instrument are compared to NO2 trends obtained from ground-based measurements at NDACC stations. For the Zvenigorod station, where vertical distribution of NO2 is retrieved from the ground-based measurements, a satisfactory correspondence of the trends calculated from satellite data to the trends calculated from measurements at the station has been obtained. For other stations where only the total column NO2 contents are measured, the correspondence of the trends calculated from satellite data and trends obtained from ground-based measurements may generally is less satisfactory.

The paper presents results of measurements and trend analysis of the mass concentration of submicron aerosol and the NO2 content in the atmospheric surface layer at the Zvenigorod Scientific Station of the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The station is located in a rural area of the western Moscow region. Aerosol concentration is determined by directional light scattering in a flow nephelometer. The NO2 content is measured spectrometrically by zenith-scattered solar radiation. Three decades of aerosol and NO2 measurements give a possibility to analyze long-term trends in near-surface aerosol and NO2. Seasonally dependent estimates of the aerosol trends are presented for three periods differing in character of aerosol variability: 1991–2002, 2003–2012, and 2013–2020. The common feature of the trends is a general decrease in the aerosol concentration. There are however significant interdecadal differences in the strength of the trends and in their seasonal dependence. The NO2 content in the near-surface layer undergoes a significant positive trend. The NO2 increase is likely associated with an increase in the population and human activity resulting, in particular, in the increase in motor traffic in the region. Effects of wind direction on aerosol and NO2 anomalies are also studied.

Results of analysis of anomalies and long-term trends in the near-surface aerosol mass concentration measured at the Zvenigorod Scientific Station (ZSS), the A.M. Obukhov Institute of Atmospheric Physics, in 1991–2019 are presented. The analysis is done with taking into account the dependence of the aerosol concentration on wind direction. Three successive periods 1991–2002, 2003–2012, and 2013–2019 that significantly differ in aerosol concentrations and their variability are considered. The second period is characterized by frequent and especially strong anomalies of high aerosol concentrations. Individual wind directions and wind direction sectors that most likely contribute to low and high aerosol concentrations have been determined. Aerosol linear trends estimated for all the three periods differ in value and features of seasonal dependence. Statistically significant seasonal trend estimates have been obtained for the winter and spring of 1991–2002; the winter, spring, and autumn of 2003–2012; and the spring, summer, and autumn of 2013–2019. The annual trend estimates are negative for the all three periods. The mass concentration of near-surface aerosol has generally decreased over the past 30 years, although the decrease is nonuniform.

This paper reports on consolidated ground-based validation results of the atmospheric NO2 data produced operationally since April 2018 by the TROPOspheric Monitoring Instrument (TROPOMI) on board of the ESA/EU Copernicus Sentinel-5 Precursor (S5P) satellite. Tropospheric, stratospheric, and total NO2 column data from S5P are compared to correlative measurements collected from, respectively, 19 Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS), 26 Network for the Detection of Atmospheric Composition Change (NDACC) Zenith-Scattered-Light DOAS (ZSL-DOAS), and 25 Pandonia Global Network (PGN)/Pandora instruments distributed globally. The validation methodology gives special care to minimizing mismatch errors due to imperfect spatiotemporal co-location of the satellite and correlative data, e.g. by using tailored observation operators to account for differences in smoothing and in sampling of atmospheric structures and variability and photochemical modelling to reduce diurnal cycle effects. Compared to the ground-based measurements, S5P data show, on average, (i) a negative bias for the tropospheric column data, of typically −23 % to −37 % in clean to slightly polluted conditions but reaching values as high as −51 % over highly polluted areas; (ii) a slight negative median difference for the stratospheric column data, of about −0.2 Pmolec cm−2, i.e. approx. −2 % in summer to −15 % in winter; and (iii) a bias ranging from zero to−50 % for the total column data, found to depend on the amplitude of the total NO2 column, with small to slightly positive bias values for columns below 6 Pmolec cm−2 and negative values above. The dispersion between S5P and correlative measurements contains mostly random components, which remain within mission requirements for the stratospheric column data (0.5 Pmolec cm−2) but exceed those for the tropospheric column data (0.7 Pmolec cm−2). While a part of the biases and dispersion may be due to representativeness differences such as different area averaging and measurement times, it is known that errors in the S5P tropospheric columns exist due to shortcomings in the (horizontally coarse) a priori profile representation in the TM5-MP chemical transport model used in the S5P retrieval and, to a lesser extent, to the treatment of cloud effects and aerosols. Although considerable differences (up to 2 Pmolec cm−2 and more) are observed at single ground-pixel level, the near-real-time (NRTI) and offline (OFFL) versions of the S5P NO2 operational data processor provide similar NO2 column values and validation results when globally averaged, with the NRTI values being on average 0.79 % larger than the OFFL values.

The data of measurements of the NO2 content in the vertical columns of the stratosphere and troposphere with the Ozone Monitoring Instrument (OMI) aboard the Aura satellite in 2004–2020 are compared to the results of ground-based spectrometric NO2 measurements at the Zvenigorod Scientific Station of the A. M. Obukhov Institute of Atmospheric Physisc, Russian Academy of Sciences, The mean annual and seasonally dependent values of the discrepancy and correlations between the data of the satellite and ground-based measurements are obtained. The dependence of the discrepancy and correlation on the cloud cover and on the level of pollution of the atmospheric boundary layer by nitrogen oxides is revealed.

Results of 31-year remote spectrometric measurements of the NO2 vertical distribution at the Zvenigorod Scientific Station of the A. M. Obukhov Institute of Atmospheric Physics of the Russian Academy of Sciences in the western Moscow region are analyzed. Seasonally dependent estimates of linear trends and interannual variations of the NO2 contents in the stratosphere and troposphere under the influence of various natural factors are obtained.