N. F. Elansky

Spatial and Temporal Variability of the NO2 Total Content Based on Annual Observation Data

Beginning from 1979 NO2 total content measurements have been taking place on a research station of the Institute of Atmospheric Physics of the USSR Academie of Sciences in North Caucasus (43.7° N, 42,7°E; 2070 m above the sea level). Similar observations were carried out in several 1983-84 aircraft flights. Results of these observations are compared to the measurement data of stratospheric NO2. The analysis of the NO2 total content suggests that the Lover stratosphere contributes greately, often critically, to the NO2 total content variability. This suggestion is confirmed by a characteristic relationship of NO2 and ozone total content variations. Some examples are given to illustrate the strong influence of dynamic processes in the stratospheric region below 20 km on NO2 total content variations.

On contents of trace gases in the atmospheric surface layer over Moscow

The results of the 2002–2012 continuous once-a-minute measurements of the composition of the surface air over Moscow, which were taken at the joint ecological station of the Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, and the Geographic Faculty of Moscow State University, are discussed. It is shown that the annual increase (on the order of 1%) in the content of surface ozone is stable and the decrease in the content of nitric oxide is statistically significant, while the content of nitric dioxide remains almost unchanged. Reliable regularities in both diurnal and annual variations in the contents of the five trace gases O3, NO, NO2, CO, and SO2 have been studied in detail. Statistical relations of the content of sulfur dioxide with the amount of reserve fuel (black oil) used in city heating (this relation is the strongest one), wind velocity in an atmospheric layer up to a height of 200 m, and air temperature have been analyzed. The influence that wind velocity has on the surface contents of trace gases and carbon dioxide has been studied for the first time on the basis of long-term ‘MODOS’ sodar data. It is shown that, with an increase in wind velocity, the contents of nitric and carbon oxides generally decrease, the content of ozone increases, and the content of sulfur dioxide decreases starting from an intermediate value of 1–2 m/s due to the prevalence of high sources of this gas. An additional maximum found in the content of carbon dioxide at high wind velocities may be associated with the long-range transport of CO2.

Estimation of biogenic CH4 and CO2 emissions and dry deposition of O3 using 222Rn measurements in TROICA expeditions

On the basis of simultaneous measurements of surface concentrations of CH4, CO2, O3, and 222Rn during 6 TROICA (TRanscontinental Observations Into the Chemistry of the Atmosphere) expeditions along the Trans-Siberian Railway from Moscow to Vladivostok in 1999–2008, we have estimated the biogenic emissions of CH4 and CO2 from terrestrial ecosystems and the nighttime sink of O3 on the underlying surface from data on the accumulation rate of 222Rn under conditions of near-surface temperature inversion. The regional emissions of CH4 were the highest in summer in the Far East (0.87 ± 0.52 μg m−2 s−1) and in West Siberia (0.77 ± 0.41 μg m−2 s−1), which is associated with significant methane flows from wetlands and moist soils that are typical for these regions. The biogenic emissions of CO2 vary on average from 0.18 ± 0.04 μg m−2 s−1 in West Siberia to 0.89 ± 0.07 μg m−2 s−1 in East Siberia. The nighttime sink of O3 has a seasonal maximum in summer and varies from 0.05 ± 0.01 μg m−2 s−1 in West Siberia to 0.07 ± 0.01 μg m−2 s−1 in Central Siberia; the dry deposition rate of O3 varies from 0.10 ± 0.08 cm s−1 in West Siberia to 0.33 ± 0.21 cm s−1 in East Siberia and the Far East.

Variations in PM2.5 Surface Concentration in Moscow according to Observations at MSU Meteorological Observatory

We considered Moscow-specific features of time variations in PM2.5 mass concentration in the surface air layer as a function of a number of atmospheric parameters such as the concentrations of certain atmospheric trace gases, aerosol optical depth, surface air temperature, humidity, and wind speed. The time series of concentrations of PM2.5 and gaseous pollutants SO2, NH3, NOx, CO, and O3, obtained during continuous observations in 2011–2013, were analyzed. We studied the diurnal and seasonal variations in concentrations of PM2.5 and the trace gases, revealed correlations between them, analyzed variations in PM2.5 concentration as a function of concentration of certain gases participating in the formation of atmospheric aerosols, and as a function of meteorological parameters. Data on PM2.5 surface concentrations are compared with measurements of aerosol optical depth.

Mountain wave-induced variations of ozone and total nitrogen dioxide contents over the Subpolar Urals

Wavy spatial variations in the contents of trace gases are identified using plane measurements of O3 concentrations in the medium troposphere and the total content (TC) of NO2 in the atmospheric column from flights above the Subpolar Urals in April 1984. The results of model calculations allow us to relate these variations to mesoscale atmospheric disturbances above the mountains, which are caused by the influence of dynamic relief on the leaked-in flow.

Aromatic volatile organic compounds and their role in ground-level ozone formation in Russia

This paper reports proton mass spectrometry data on aromatic volatile organic compounds (VOCs) (benzene, toluene, phenol, styrene, xylene, and propylbenzene) obtained in different Russian regions along the Trans-Siberian Railway from Moscow to Vladivostok, based on expedition data retrieved using the TRO-ICA-12 mobile laboratory in the summer of 2008. The contribution of aromatic VOCs to ozone formation in the cities and regions along the measurement route has been estimated quantitatively. The greatest contribution of aromatic VOCs to ozone formation is characteristic of large cities along the Trans-Siberian Railway (up to 7.5 ppbv O3) specified by the highest concentrations of aromatic VOCs (1–1.7 ppbv) and nitrogen oxides (>20 ppbv). The results obtained are indicative of a considerable contribution (30–50%) of anthropogenic emissions of VOCs to photochemical ozone generation in the large cities along the Trans-Siberian Railway in hot and dry weather against the background of a powerful natural factor such as isoprene emissions controlling the regional balance of ground-level ozone in warm seasons.