A. V. Fofonov

Vertical distribution of greenhouse gases above Western Siberia by the long-term measurement data

By the results of long-term (1997–2007) airborne sounding, the vertical distribution of three greenhouse gases such as CO2, CH4, and N2O above the south of Western Siberia is investigated. The average monthly profiles of the distribution of these components in height and the long-term change in gas concentration at different heights are presented. The climatic characteristics of the vertical distribution of these gases are determined.

Spatial and temporal variability of CO2 and CH4 concentrations in the surface atmospheric layer over West Siberia

The diurnal and annual variation of the CO2 and CH4 concentrations and their spatial distribution over a network of sites developed over the territory of West Siberia are investigated. The CO2 concentration gradient between the northern and southern regions of the territory is retained during the entire year. The diurnal behavior of the methane concentration remains neutral for much of the year, so that it is only at the end of the springtime and at the beginning of the summer that it exhibits a significant amplitude. The annual variation of CO2 has a maximum in the month of December, the concentration starts to decrease in March, and reaches a minimum in July in August. In the central region of the territory, the annual variation of methane has two maxima (in July and in December and January); the greatest interyear methane concentration variability is recorded during the periods of the basic and secondary maxima.

The Blocking Role of the Ural Mountains in the Transborder Transfer of Impurities from Europe to Asia

Distribution of impurities over the region abutting the Ural Mountains is analyzed with the purpose of searching for traces of western European emissions over the territory of Siberia. It is shown that transborder transfer of impurities from Europe to Asia along direct trajectories (along a circle of latitude) from west to east is possible only in the free troposphere, in a layer higher than 2 km. Within the limits of the atmospheric boundary layer, the transfer of impurities from Europe to Siberia is probable only along trajectories rounding the Urals from north or south.

The scale of ozone destruction in clouds

Changes in the concentration of tropospheric ozone in clouds were investigated based on aircraft sensing data. Three ozonometers were used for the measurements—one chemiluminescent 3-02P and two UV 49C (Thermo Environment Inc., United States). The following types of clouds were studied: Cu, Cu med., St, Sc, As, and Ac. The thickness of the cloud layers was 1.5 km on average and varied from 0.4 to 4.5 km. The ozone destruction in clouds was 11–15 ppb on average and ranged from 3 to 34 ppb; it changed nearly twofold depending on the cloud type. The estimation of the annual runoff of ozone in clouds has shown that it is close to the annual ozone balance in the troposphere.

Comparison between satellite spectrometric and aircraft measurements of the gaseous composition of the troposphere over Siberia during the forest fires of 2012

The vertical profiles of the O3, CO, CO2 and CH4 concentrations measured onboard the Optik Tu-134 aircraft laboratory and retrieved from data obtained with an IASI Fourier transform spectrometer operating aboard a MetOp satellite (European Space Agency) have been compared. This comparison shows that absolute differences between aircraft satellite ozone concentrations may vary from 55 to 15 ppb at the land surface and within the lower boundary layer and from 30 to −15 ppb at a height of 7000 m. Their relative differences range within 60 to 30% at a height of 500 m and 30 to −35% at a height of 7000 m. Absolute differences between aircraft and satellite carbon-monoxide concentrations may vary from 80 to 2300 ppb, while their relative differences range within −140 to 98%. For methane, the mean difference is maximal within the atmospheric boundary layer (90 ppb). According to the data on all profiles, the maximum and minimum differences reach 220 and 8 ppb, respectively, within the atmospheric boundary layer. Minimum differences range from zero at the land surface to −100 ppb in the upper troposphere. For carbon dioxide, the mean difference between the results of aircraft and satellite measurements ranges from −2 to −9 ppm. In the free troposphere, at a height of more than 3000 m, this difference is almost constant and amounts to −6 ppm. Over all flights, the maximum and minimum differences between aircraft and satellite CO2 concentrations range from 14 to −4 ppm and from −7 to −16 ppm, respectively, within the atmospheric boundary layer. In this case, the maximum and minimum relative deviations over all flights amount to 3.4 and −4.2%, respectively, within the atmospheric boundary layer. These differences are significantly larger than those found earlier for the background conditions. It is necessary to improve the vertical gas distribution models used in the algorithms of satellite-data processing.

Ozone vertical distribution in the troposphere over south regions of Western Siberia

Dynamics of the tropospheric ozone vertical distribution over one of the Siberian regions is considered based on the data of long-term atmospheric sensing onboard the “Optik-E”. AN-30 aircraft laboratory with the use of a 3-02P chemiluminescence lidar. Two modes are clearly distinguished in the annual variation of ozone vertical distribution: autumn-winter and spring-summer. The change from the autumn-winter mode to the spring-summer one begins near the Earth’s surface in the end of February and ends in the upper troposphere in the end of April; the change back begins in the upper troposphere in the beginning of September and ends in the midtroposphere in the middle of October. Three clearly pronounced maxima and two minima were fixed in the free troposphere during the period under consideration (1997–2009). Not all of them were reflected in the ground layer, as zones of increased ozone concentrations do not reach the upper troposphere. It is most probable that ozone was generated from compounds transported from other regions, due to changes in circulation processes. Peculiarities of ozone distribution in the ground layer are also considered.

Comparative Estimation of Geochemical Activity of the Atmosphere according to the Ratio of Compositions of Different Near-Ground Aerosol Fractions at the Fonovaya Observatory in Autumn 2016

For the background region of Tom–Ob interfluve, we performed the comparative analysis of the chemical composition of water- and acid-soluble aerosol fractions in dry deposits, coupled with an estimation of the ratio of submicron and coarse fractions in near-ground aerosol in this background region, and a study of their mineral and material composition using scanning electron microscopy. Differences in the ratios of metals between the water- and acid-soluble fractions are revealed. It is reasonably hypothesized that water- (acid-) soluble compounds are mainly contained in the submicron (coarse) fraction.

Vertical Distributions of Gaseous and Aerosol Admixtures in Air over the Russian Arctic

Data on the vertical distribution of gaseous and aerosol composition of air, measured onboard the Tu-134 Optic airborne laboratory in October 2014 over the Kara Sea and coastal areas of the Russian Arctic, are presented. We revealed the specific features of the altitude distributions of CO2 and aerosol over the Kara Sea as compared to continental conditions. No significant deviations from continental distributions are found for CH4, CO, and O3.

Complex experiment on the study of microphysical, chemical, and optical properties of aerosol particles and estimation of atmospheric aerosol contribution in the Earth radiation budget

The main aim of the work was complex experimental measurements of microphysical, chemical, and optical parameters of aerosol particles in the surface air layer and free atmosphere. From the measurement data, the entire set of aerosol optical parameters was retrieved, required for radiation calculations. Three measurement runs were carried out in 2013 within the experiment: in spring, when the aerosol generation maximum is observed, in summer (July), when the altitude of the atmospheric boundary layer is the highest, and in the late summer – early autumn, when the second nucleation period is recorded. The following instruments were used in the experiment: diffusion aerosol spectrometers (DAS), GRIMM photoelectric counters, angle-scattering nephelometers, aethalometer, SP-9/6 sun photometer, СЕ 318 Sun-Sky radiometer (AERONET), MS-53 pyrheliometer, MS-802 pyranometer, ASP aureole photometer, SSP scanning photometer, TU-134 Optik flying laboratory, Siberian lidar station, stationary multiwave lidar complex LOZA-M, spectrophotometric complex for measuring total ozone and NO2, multivariable instrument for measuring atmospheric parameters, METEO-2 USM, 2.4 AEHP-2.4m station for satellite data receive. Results of numerical calculations of solar down-fluxes on the Earth’s surface were compared with the values measured in clear air in the summer periods in 2010—2012 in a background region of Siberian boreal zone. It was shown that the relative differences between model and experimental values of direct and total radiation do not exceed 1% and 3%, respectively, with accounting for instrumental errors and measurement error of atmospheric parameters. Thus, independent data on optical, meteorological, and microphysical atmospheric parameters allow mutual intercalibration and supplement and, hence, provide for qualitatively new data, which can explain physical nature of processes that form the vertical structure of the aerosol filed.