Influence of convection on the upper-tropospheric O<sub>3</sub> and NO<sub><i>x</i></sub> budget in southeastern China

Abstract

Abstract. Thunderstorms can significantly influence the air composition via strong updraft and lightning nitrogen oxides (LNOx). In this study, the ozonesondes and TROPOMI (TROPOspheric Monitoring Instrument) nitrogen dioxide (NO2) observations for two cases are combined with a model to investigate the effects of typical strong convection on vertical redistribution of air pollutants in Nanjing, southeastern China. The ozonesonde observations show higher O3 and water vapor mixing ratios in the upper troposphere (UT) after convection, indicating the strong updraft transporting lower-level air masses into the UT and the possible downward O3-rich air near the top of UT over the convective period. During the whole convection life cycle, the UT O3 production is driven by the chemistry (5–10 times the magnitude of dynamic contribution) and reduced by the LNOx (−40 %). Sensitivity tests demonstrate that neglecting LNOx in standard TROPOMI NO2 products causes overestimated air mass factors over fresh lightning regions and the opposite for outflow and aged lightning areas. Therefore, a new high-resolution retrieval algorithm is applied to estimate the LNOx production efficiency. Our work shows the demand for high-resolution modeling and satellite observations on LNOx emissions of both active and dissipated convection, especially small-scale storms.

Lightning‐Produced Nitrogen Oxides Per Flash Length Obtained by Using TROPOMI Observations and the Ebro Lightning Mapping Array

“…Recent LNO x estimates based on satellite instruments suggest that the LNO x PE per flash falls at the lower end of the range of estimations reported in literature (100–400 mol NO x per flash) (Beirle et al., 2004; Schumann & Huntrieser, 2007). In particular, LNO x estimates based on TROPOMI NO 2 retrieval, the most modern global air quality satellite in operation, have produced LNO x PE estimates of 175 ± 100 mol and 120 ± 65 mol NO x per flash in the United States of America (USA) (Allen, Pickering, Bucsela, et al., 2021) by using lightning measurements from the Geostationary Lightning Mapper (GLM) and the Earth Networks Global Lightning Network (ENGLN), respectively, 58 ± 44 mol NO x per flash in the Ebro Valley and the Pyrenees (Pérez‐Invernón et al., 2022), and 60 ± 33 mol NO x per flash in southeastern China (Zhang et al., 2022).…”

“…PE estimates of 175 ± 100 mol and 120 ± 65 mol NO x per flash in the United States of America (USA) (Allen, Pickering, Bucsela, et al, 2021) by using lightning measurements from the Geostationary Lightning Mapper (GLM) and the Earth Networks Global Lightning Network (ENGLN), respectively, 58 ± 44 mol NO x per flash in the Ebro Valley and the Pyrenees (Pérez-Invernón et al, 2022), and 60 ± 33 mol NO x per flash in southeastern China (Zhang et al, 2022). Some studies based on laboratory discharges have reported a positive relationship between the flash energy and the production of LNO x (Allen, Pickering, Lamsal, et al, 2021;Stark et al, 1996;Wang et al, 1998).…”

The impact of COVID-19 lockdown on ozone budget and radical chemistry in a typical industrial city of China

“…Therefore, it is essential to distinguish the contributions of meteorological parameters and emission change firstly, and then to figure out the O3 formation mechanisms and sensitivity. Unfavorable meteorological condition was often considered to be the key factor for the O3 increase (Yin et al, 2021;Zhang et al, 2022b). Gong et al (2018) revealed that daily maximum temperature was major driving factor responsible for the national O3 pollution.…”