# Nitrogen oxides in the global upper troposphere: interpreting cloud-sliced NO 2 observations from the OMI satellite instrument

Nitrogen oxides (inline-formula $M2inlinescrollmathmlchem{\mathrm{normal NO}}_{x}\equiv \mathrm{normal NO}+{\mathrm{normal NO}}_{normal 2}$ 85pt13ptsvg-formulamathimgf610f94fb6c20199e6f641866e657b1f acp-18-17017-2018-ie00001.svg85pt13ptacp-18-17017-2018-ie00001.png ) in the upper troposphere (UT) have a large impact on global tropospheric ozone and OH (the main atmospheric oxidant). New cloud-sliced observations of UT inline-formulaNO2 at 450–280 hPa (inline-formula∼6–9 km) from the Ozone Monitoring Instrument (OMI) produced by NASA and the Royal Netherlands Meteorological Institute (KNMI) provide global coverage to test our understanding of the factors controlling UT inline-formulaNOx. We find that these products offer useful information when averaged over coarse scales (inline-formula $M6inlinescrollmathmlnormal 20{}^{\circ }×normal 32{}^{\circ }$ 46pt11ptsvg-formulamathimg55f159cafb79d8ecf49805e6c5c5fba2 acp-18-17017-2018-ie00002.svg46pt11ptacp-18-17017-2018-ie00002.png , seasonal), and that the NASA product is more consistent with aircraft observations of UT inline-formulaNO2. Correlation with Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) satellite observations of lightning flash frequencies suggests that lightning is the dominant source of inline-formulaNOx to the upper troposphere except for extratropical latitudes in winter. The inline-formulaNO2 background in the absence of lightning is 10–20 pptv. We infer a global mean inline-formulaNOx yield of inline-formula280±80 moles per lightning flash, with no significant difference between the tropics and midlatitudes, and a global lightning inline-formulaNOx source of inline-formula5.9±1.7 Tg N ainline-formula−1. There is indication that the inline-formulaNOx yield per flash increases with lightning flash footprint and with flash energy.

### Zitieren

Zitierform:

Marais, Eloise A. / Jacob, Daniel J. / Choi, Sungyeon / et al: Nitrogen oxides in the global upper troposphere: interpreting cloud-sliced NO2 observations from the OMI satellite instrument. 2018. Copernicus Publications.

### Zugriffsstatistik

Gesamt:
Volltextzugriffe: