Variations of Total Nitrogen Oxide Content in the Atmosphere over the North Caucasus

The data are presented on total nitrogen dioxide (NO₂) content in the atmosphere from 1979 to 2009 at the high-mountain scientific station located in the unpolluted area in the North Caucasus at the height of 2070 m above the sea level (43.7° N, 42.7° E). The total content of NO₂ was measured on the basis of attenuation of direct solar radiation over slope pathways after the sunrise and before the sunset. Characteristics features are analyzed of temporal variability of total NO₂ content in the atmosphere related to its diurnal and seasonal variations, 11-year solar activity, volcanic eruptions, quasi-biennial oscillations of tropical circulation, and the El Niño effect.     

Long-Term Observations of Stratospheric Species at the A. M. Obukhov Institute of Atmospheric Physics,Russian Academy of Sciences: Analysis of Trends and Interannual Variations in the Total Contents of O3 and NO2

Izvestiya, Atmospheric and Oceanic Physics - 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...     

Winter–spring anomalies in stratospheric O<Subscript>3</Subscript> and NO<Subscript>2</Subscript> contents over the Moscow region in 2010 and 2011

Using results of ground-based spectrometric measurements, we analyze the anomalies in the stratospheric contents of O₃ and NO₂ in the Moscow region related to the sudden stratospheric warming and associated distortion of the stratospheric circumpolar vortex in early February 2010 and to the latitudinal displacement of the vortex towards the European sector in late March 2011 before the final spring warming. In the former case, the O₃ concentration increased up to 85% and the stratospheric column NO₂ content increased twice; in the latter case, the O₃ concentration decreased by a quarter and the NO₂ content decreased twice in comparison with average values for the time periods preceding the onsets of the anomalies. Estimates of the statistical correlationship of the stratospheric O₃ and NO₂ contents with potential vorticity and geopotential have been obtained.     

Increase in the Stratospheric NO2 Content Derived from Results of Ground-Based Observations after the October 2003 Solar Proton Event

Doklady Earth Sciences - This paper reports on the first experimental evidence of the impact of a solar proton event on the stratospheric NO2 content derived from ground-based spectrometric...     

Changes in Vertical Distribution and Column Content of NO<Subscript>2</Subscript> under the Influence of Sudden Stratospheric Warmings

Characteristic features of changes in the vertical distribution and column content of NO₂, total ozone, and stratospheric temperature have been revealed as a result of major sudden stratospheric warmings (SSWs). Strong negative anomalies of column NO₂, total ozone and stratospheric temperature are caused by the displacement of the stratospheric circumpolar vortex aside from the pole. Strong positive anomalies of column NO₂ and total ozone are observed more frequently under SSWs accompanied by splitting of the stratospheric circumpolar vortex and are caused by the transport of stratospheric air from the low latitudes. Major SSWs can lead to significant changes in the vertical profile of NO₂. The changes in different stratospheric layers can be opposite to each other when the edge of the polar vortex is over a site of ground-based observations.     

Changes in the Column Content and Vertical Distribution of NO2 According to the Results of 30-Year Measurements at the Zvenigorod Scientific Station of the A. M. Obukhov Institute of Atmospheric Physics,Russian Academy of Sciences

Izvestiya, Atmospheric and Oceanic Physics - The results of an analysis of variations and linear trends in the column content and vertical distribution of NO2 are presented based on 30-year...     

Gaseous admixtures in the atmosphere over Moscow during the 2010 summer

In the summer of 2010, the Moscow megacity during two months was within the zone of action of a blocking anticyclone. The accumulation of pollutants in a closed air mass sharply changed the surface air quality. At the end of July-the first half of August, the extreme situation became even more complicated, because the air from regions of turf and grass fires came into Moscow. According to measurement data of the Moscow IAP RAS station, the maximal hourly mean concentrations of chemically active gases NO, NO₂, CO, O₃, and SO₂ were 175.9, 217.4, 15.8, 134.2, and 15.2 ppb, respectively. For NO₂ and CO, these values are largest over the entire decadal period of observations at the station and many times exceed the MPC level (see table). The concentrations of greenhouse gases CO₂, CH₄, and nonmethane hydrocarbons also sharply increased. Analysis of the variability of gas contents in the surface air and in the atmospheric boundary layer showed a close relation between extreme changes in the atmospheric composition and its vertical stratification.     

Sudden stratospheric warmings: statistical characteristics and influence on NO<Subscript>2</Subscript> and O<Subscript>3</Subscript> total contents

Statistical characteristics of major and minor sudden stratospheric warmings (SSWs) in the Northern Hemisphere (NH) for 1958–2015 are analyzed using data of NCEP-NCAR, ERA 40, and ERA-Interim reanalyses. Dependencies of the number of major SSWs with the displacement of the circumpolar stratospheric vortex and the number of minor SSWs on the phase of the quasi-biennial oscillation (QBO) of the equatorial stratospheric wind and on the level of solar activity (SA) in the 11-year solar cycle have been revealed. Major SSWs accompanied by a displacement of the polar vortex occur more often at a high level of SA and at the easterly phase of the QBO in the 50–40 hPa layer, while minor SSWs occur more often at a low SA level and at the westerly phase of the QBO. An analysis of spatiotemporal dynamics of the stratospheric polar vortex at major SSWs is performed. The most probable directions of vortex displacement caused by SSWs have been revealed. Influences of the major SSWs on the total contents of NO₂ and ozone, as well as on stratosphere temperature, are analyzed.