Estimates of lightning NO&amp;lt;sub&amp;gt;&amp;lt;i&amp;gt;x&amp;lt;/i&amp;gt;&amp;lt;/sub&amp;gt; production based on high-resolution OMI NO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; retrievals over the continental US

Xin Zhang,Shuqi Yan,Ronald Van Der A,Yan Yin,Rulin Shi,Jeff L Lapierre,Qian Chen,Chuan He,Jinghua Chen,Xiang Kuang

doi:10.5194/amt-13-1709-2020

Abstract

Abstract. Lightning serves as the dominant source of nitrogen oxides (NOx=NO+NO2) in the upper troposphere (UT), with a strong impact on ozone chemistry and the hydroxyl radical production. However, the production efficiency (PE) of lightning nitrogen oxides (LNOx) is still quite uncertain (32–1100 mol NO per flash). Satellite measurements are a powerful tool to estimate LNOx directly compared to conventional platforms. To apply satellite data in both clean and polluted regions, a new algorithm for calculating LNOx has been developed that uses the Berkeley High-Resolution (BEHR) v3.0B NO2 retrieval algorithm and the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). LNOx PE over the continental US is estimated using the NO2 product of the Ozone Monitoring Instrument (OMI) data and the Earth Networks Total Lightning Network (ENTLN) data. Focusing on the summer season during 2014, we find that the lightning NO2 (LNO2) PE is 32±15 mol NO2 per flash and 6±3 mol NO2 per stroke while LNOx PE is 90±50 mol NOx per flash and 17±10 mol NOx per stroke. Results reveal that our method reduces the sensitivity to the background NO2 and includes much of the below-cloud LNO2. As the LNOx parameterization varies in studies, the sensitivity of our calculations to the setting of the amount of lightning NO (LNO) is evaluated. Careful consideration of the ratio of LNO2 to NO2 is also needed, given its large influence on the estimation of LNO2 PE.

Highlights

Nitrogen oxides (NOx) near the Earth’s surface are mainly produced by soil, biomass burning, and fossil fuel combustion, while NOx in the middle and upper troposphere originates largely from lightning and aircraft emissions
Apart from the fewer valid days under higher cloud radiance fraction (CRF) conditions (CRF ≥ 90 % and CRF = 100 %), lightning nitrogen oxides (LNOx) per flash increases from 35.7 ± 36.8 to 54.5 ± 48.1 mol per flash and decreases again to 20.8 ± 37.4 mol per flash while LNOx per stroke enhances from 4.1 ± 3.9 to 7.0 ± 4.8 mol per stroke and drops again to 2.6 ± 4.0 mol per stroke (Table 3), as the CRF criterion increases from 70 % to 90 % and to 100 %
A new algorithm for retrieving lightning NO2 (LNO2) (LNOx) from Ozone Monitoring Instrument (OMI), including LNO2 (LNOx) below cloud, has been developed for application over active convection. It works in both clean and polluted regions because of the consideration of tropospheric background pollution in the definition of air mass factor (AMF). It uses specific criteria combined with several other conditions to ensure that the electrically active regions are detected by OMI and simulated by WRFChem successfully

Summary

Introduction

Nitrogen oxides (NOx) near the Earth’s surface are mainly produced by soil, biomass burning, and fossil fuel combustion, while NOx in the middle and upper troposphere originates largely from lightning and aircraft emissions. With the recent updates of UT NOx chemistry, the daytime lifetime of UT NOx is evaluated to be ∼ 3 h near thunderstorms and ∼ 0.5–1.5 d away from thunderstorms (Nault et al, 2016, 2017). This results in enhanced O3 production in the cloud outflow of active convection (Pickering et al, 1996; Hauglustaine et al, 2001; DeCaria et al, 2005; Ott et al, 2007; Dobber et al, 2008; Allen et al, 2010; Finney et al, 2016).

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Results

Conclusion