Estimates of lightning NO_x production based on OMI NO₂ observations over the Gulf of Mexico

Abstract

We evaluate nitrogen oxide (NO x = NO + NO 2 ) production from lightning over the Gulf of Mexico region using data from the Ozone Monitoring Instrument (OMI) aboard NASA's Aura satellite along with detection efficiency-adjusted lightning data from the World Wide Lightning Location Network (WWLLN). A special algorithm was developed to retrieve the lightning NO x (LNO x ) signal from OMI. The algorithm in its general form takes the total slant column NO 2 from OMI and removes the stratospheric contribution and tropospheric background and includes an air mass factor appropriate for the profile of lightning NO x to convert the slant column LNO 2 to a vertical column of LNO x . WWLLN flashes are totaled over a period of 3 h prior to OMI overpass, which is the time an air parcel is expected to remain in a 1°× 1°grid box. The analysis is conducted for grid cells containing flash counts greater than a threshold value of 3000 flashes that yields an expected LNO x signal greater than the background. Pixels with cloud radiance fraction greater than a criterion value (0.9) indicative of highly reflective clouds are used. Results for the summer seasons during 2007-2011 yield mean LNO x production of~80 ± 45 mol per flash over the region for the two analysis methods after accounting for biases and uncertainties in the estimation method. These results are consistent with literature estimates and more robust than many prior estimates due to the large number of storms considered but are sensitive to several substantial sources of uncertainty.

The Ozone Monitoring Instrument: overview of 14 years in space

“…7), it has also been applied to NO 2 with OMI to derive information about its concentration in the free troposphere (Choi et al, 2014;Belmonte Rivas et al, 2015). In addition, other approaches have been applied to isolate NO 2 generated from lightning Pickering et al, 2016).…”

The version 3 OMI NO<sub>2</sub> standard product

“…Recent research has shown that satellite measurements are a useful tool for estimating LNO x (Boersma et al, 2005;Beirle et al, 2010;Bucsela et al, 2010;Pickering et al, 2016). Pickering et al (2016) combined OMI V trop data with data from the World Wide Lightning Location Network (WWLLN) (Dowden et al, 2002;Lay et al, 2004;Virts et al, 2013) to estimate the production efficiency (PE) of LNO x (moles per flash). Using SPv2 and WWLLN data from the Gulf of Mexico over five Northern Hemisphere summers (2007)(2008)(2009)(2010)(2011), they obtained a mean PE value of 80 ± 45 mol flash −1 .…”

A high-resolution and observationally constrained OMI NO<sub>2</sub> satellite retrieval

“…Satellite instruments measure the absorption of solar backscatter in the UVvisible spectral range, enabling estimation of the amount of NO 2 in the atmosphere between the instrument and the surface. By comparing observed spectra with a reference spectrum, we can derive total column amounts; this technique is called differential optical absorption spectroscopy (DOAS) (Platt, 1994).…”