Impact of VOCs and NOx on Ozone Formation in Moscow

Abstract

Volatile organic compounds (VOCs), ozone (O3), nitrogen oxides (NOx), carbon monoxide (CO), meteorological parameters, and total non-methane hydrocarbons (NMHC) were analyzed from simultaneous measurements at the MSU-IAP (Moscow State University—Institute of Atmospheric Physics) observational site in Moscow from 2011–2013. Seasonal and diurnal variability of the compounds was studied. The highest O3 concentration in Moscow was observed in the summer daytime periods in anticyclonic meteorological conditions under poor ventilation of the atmospheric boundary layer and high temperatures (up to 105 ppbv or 210 μg/m3). In contrast, NOx, CO, and benzene decreased from 8 a.m. to 5–6 p.m. local time (LT). The high positive correlation of daytime O3 with secondary VOCs affirmed an important role of photochemical O3 production in Moscow during the summers of 2011–2013. The summertime average concentrations of the biogenic VOCs isoprene and monoterpenes were observed to be 0.73 ppbv and 0.53 ppbv, respectively. The principal source of anthropogenic VOCs in Moscow was established to be local vehicle emissions. Yet, only about 5% of the observed isoprene was safely attributed to anthropogenic sources, suggesting significant contribution of biogenic sources into the total levels of ozone precursors. The non-linear O3–NOx dependence shows a decrease in ground-level O3 with an increase in NOx during the summers of 2011–2013, which is typical for the VOC-sensitive photochemical regime of O3 formation. Nevertheless, during the elevated ozone episodes in July 2011, the photochemical regime of ozone production was either transitional or NOx-sensitive. Contribution of various anthropogenic and biogenic VOCs into the measured ozone values was evaluated. The ozone-forming potential (OFP) of total VOCs was 31–67 μg/m3 on average and exceeded 100 μg/m3 in the top 10% of high ozone events, reaching 136 μg/m3. Acetaldehyde, 1.3-butadiene, and isoprene have the highest ozone production potential in Moscow compared to that of other measured VOCs.

The Dynamics Of The Atmospheric Pollutants During The Covid-19 Pandemic 2020 And Their Relationship With Meteorological Conditions In Moscow

“…10 shows the dependence of the O 3 mass concentration on NOx for different lockdown periods and SII ranges. In general, for all conditions we obtained non-linear relationship between O3 and NOx similar to that obtained by Zillman (1999) and Berezina et al (2020).…”

“…One can see that for all SII ranges, O 3 increased more efficiently with an increase in the proportion of organic compounds at the same content of NOx, which is consistent with data analysis shown by Berezina et al (2020). At the same time, in conditions with relatively high SII (i.e.…”

The Seasonality Impact of the BTEX Pollution on the Atmosphere of Arad City, Romania

“…In Jeddah, a coastal city in Saudi Arabia, the BTEX determinations showed seasonal variation during a one-year experiment, with higher concentrations during the spring and lower concentrations during the autumn [ 21 ]. The results obtained after a long-term (2011–2013) determination of volatile organic compounds in Moskow, Russia, revealed that BTEX made a lesser contribution to O 3 formation in the city [ 22 ].…”

Removal of VOCs by Ozone: n-Alkane Oxidation under Mild Conditions

“…[1]. VOCs are considered major air pollutants because of their significant contribution to the formation of photochemical smog, tropospheric O 3 and secondary aerosols [2][3][4][5]. VOCs negatively affect human health because of their toxic, malodorous, mutagenic and carcinogenic nature [6].…”