Influence of air mass transport directions on the seasonal variations of concentrations of minor gas atmospheric components in Europe

Abstract

The integrated assessment of the influence of air mass transport directions on the average long-term seasonal variations of concentrations of minor gas components (MGC: ozone, CO, NO 2 ) of the atmosphere is carried out according to the data of a number of European stations. Distributions of nitrogen dioxide and carbon monoxide concentrations according to transport directions are similar to each other and differ considerably from the distribution of ozone concentrations. It is demonstrated that the relationships of levels of spring and summer ozone concentrations maxima differ considerably at all examined stations in different regions of Europe depending on different transport directions: the summer maximum is stronger pronounced according to the data for the southern and eastern directions than according to the data for the northern and western directions. The change of air transport directions may account for from 10% (Moscow region) to 30-40% (the northwest of continental Europe and Ireland) variations of MGC concentration. The obtained results point out the perspective of their use in statistical models of the forecast of MGC concentrations.In view of the urgent problem of investigation of the air quality, the important problem is the revelation of variability of concentration of the surface ozone and a number of its predecessors: nitrogen oxide (NO x = = NO + NO 2 ) and carbon monoxide (CO). The ozone predecessors in the boundary layer of atmosphere are mainly of the anthropogenic origin and are the primary pollutants, and the ozone is the secondary one (i.e., its high concentrations are generated during the photochemical reactions with the participation of primary pollutants and volatile organic compounds), especially in populous regions. The natural sources also contribute to the generation of observed concentrations of CO (biomass combustion) and NO x (lightnings), however, this contribution is considerably smaller than the anthropogenic activity. Variations in concentrations of the above atmospheric components are determined to a considerable degree by meteorological factors, first of all, by the temperature regime and processes, influencing the inflow and scattering of admixtures, among which the important role belongs to the processes of air mass transport. Generally, the transport characteristics are used to account for certain peculiarities of ozone concentration variations [6,[8][9][10][11]13] but they can be used in models for ozone concentration forecasting [4,5,7]. The reasons causing high ozone concentrations, in particular, those associated with the emission and transport of atmospheric pollutants, are actively studied in Europe in view of frequently repeated episodes of reaching the dangerous concentrations and observed global increase in the ozone concentration [8,10,11]. In this work, the integrated assessment of the influence of air mass transport directions on average long-term seasonal variations of concentrations of minor gas components (MGC: ozone, CO, NO 2 ) of atmosphere for the purpo...

Anomalies of trace gases in the air of the European part of Russia and Ukraine in summer 2010

“…A blocking anticyclone set in above the ETR became the reason for an atypical air mass transfer in the Moscow region: southeasters, causing increased surface ozone concentrations, prevailed instead of northwesters, usual for summer ( Fig. 1) [16].…”

Trends of surface ozone concentrations in germany and their connections with changes in meteorological variables

“…The selection of meteorological variables is determined by their significant influence on ozone concentration [1,2,7,17]. The possibility to take into account the wind speed was also tried, but the coefficient of correlation of residue series of ozone and wind speed over the entire period of observations was not higher than 0.20-0.26, and the influence of changes in the wind speed on the ozone trends turned out to be statistically insignificant at all stations.…”

“…The ozone concentration substantially depends on a great number of factors (meteorological variables, atmospheric composition, solar radiation) [1,2,6,10,12], whose trends can significantly influence the ozone trend. The influence of meteorological variables on the ozone trend can be taken into account using instead of formula (2) the following relation [6]: …”

“…The model quality generally significantly increases (approximately to 0.6), when the relation between ozone concentration and influencing factors is taken into account [2]. The time series of differences of the O 3j (t) norms for the jth direction of the air mass transport and O 3 (t) norms for all air mass transport directions is used as a deviation of meteorological variables for the jth direction of the transport [1].…”

“…Therefore, in the USA, for the maximally possible detection of climate changes, several basic observatories were organized in the mid-1970s; they are located in different regions of the world, between the South Pole and the northern Alaskan coast, where highly-precise measurements of the surface ozone (hereafter ozone) are carried out [14]. Long-term changes in ozone concentration at these observatories are not unidirectional and their interpretation is ambiguous [1,14]. Based on the most probable scenarios on changes in the troposphere gas composition and different photochemical models, numerous forecasts of changes in the ozone content in the current century on the global scale [13,16,18] were published, however, they are not yet confirmed by the observation data, in particular, from the American stations [14].…”