Regional Photochemical Surface-Ozone Sources in Europe and Western Siberia

Surface Ozone Concentration over Russian Territory in the First Half of 2020

“…They showed almost constant photochemical ozone generation in the surface or atmospheric boundary layers. These data also contradict the conclusions [ 36 ] about the 20–30% contribution of sources in European Russia and western Siberia to the photochemical ozone generation. It is difficult to explain this fact.…”

Regional Impact of Ozone Precursor Emissions on NOX and O3 Levels at ZOTTO Tall Tower in Central Siberia

“…(2012) adapted in the GEOS‐Chem model give the domain‐total annual emissions of 0.28–0.36 Tg NO X . This is comparable to the 0.6 Tg of anthropogenic and 0.08–0.18 Tg of wildfire NO X emissions in the region (Moiseenko et al., 2018), thus suggesting an important role of biogenic NO X in the regional ozone photochemistry. The observed difference between the O 3 –temperature slope rates in REI and CB air in summer (2.2 vs. 0.9 ppbv O 3 per °C) then quantifies a direct effect of anthropogenic and fire‐emitted NO X on the net ozone production in addition to the temperature‐controlled NO X emissions from biogenic sources.…”

“…As far as the measured NO X abundance at ZOTTO can be viewed as a proxy for the amount of NO X emitted from upwind sources, the observed increase of daytime ozone with the in situ [NO X ] levels provides observational evidence for photochemical production of ozone within CBL on a regional scale in the warm season. Recent numerical sensitivity experiments conducted with the GEOS‐Chem chemical transport model (Moiseenko et al., 2018) for the region of Siberia showed that a 50% reduction in biogenic volatile organic compounds (BVOCs) emissions results in a 1.6 ppbv decrease in the regional ozone levels in summer, whereas a 50% reduction in anthropogenic NO X emissions results in a 2.7 ppbv decrease in ozone on average. This evidently suggests a NO X ‐sensitive regime of ozone production on a regional scale in a photochemically active season.…”

“…Hence, air pollutant emissions in Siberia provide a net source for ozone in CBL over central North Eurasia for an appreciably longer period of year compared to the similar effect of emissions for the region of Western Europe. The prolonged period of net photochemical ozone production in Siberia can be explained at least partially by substantially weaker anthropogenic NO X emissions in the region compared to those in Western Europe (Moiseenko et al., 2018) and proportionally lower NO X levels in the CBL. During late winter and early spring under low solar radiation, the efficiency of photochemical ozone production through the chemical chain reactions involving NO X is expected to be low under strongly limited tropospheric hydroxyl abundance, so that titration of the ozone by reaction with anthropogenic NO x still contributes to ozone destruction at a rate that is proportional to the regional NO X supply.…”

Passive Sampling as a Low-Cost Method for Monitoring Air Pollutants in the Baikal Region (Eastern Siberia)

“…For a long time, it was believed that the main source of ozone in surface air was an intrusion from the overlying layers of the atmosphere. However, recently, it is found that photochemical generation involving NO x under the action of solar radiation largely contributes to the tropospheric ozone budget [32][33][34], and serves as a secondary pollutant [35,36].…”