Analysis of OMI tropospheric NO2 data in relation to global lightning flash data
October 26, 2012 15:25:40
Description of Problem
This effort will be aimed at estimating NOx production from lightning through analysis of Aura/OMI tropospheric NO2 data. The second major data set to be utilized will be the World Wide Lightning Location Network (WWLLN) flash data. The OMI data (which have been retrieved especially for quantifying the lightning impact) and the WWLLN data will be allocated to the NASA Global Modeling Initiative (GMI) global grid. Analysis will be conducted on this grid to identify matches between major lightning events and the Aura/OMI overpass. Mean NOx production per flash will be computed for each grid cell.
Scientific Objectives and Approach
The lightning data gathered from the World Wide Lightning Location Network (WWLLN) will be been plotted for years 2007 and 2008 to describe daily, monthly, and seasonally occurring flash rates. This coupled with flash rate information from Optical Transient Detector and Lightning Imaging Sensor (OTD/LIS) satellite instruments will provide an understanding of global flash rates for 2007 and 2008. Comparison of these two data sets will allow determination of detection efficiencies for WWLLN. The WWLLN data (adjusted for detection efficiency) will then be compared to the Aura/OMI satellite NOx data, specifically for storm events. This comparison will help to quantify average NOx production per lightning flash (LNOx production). GMI simulations with and without lightning will be used to estimate background tropospheric NOx, determining scaling factors to ensure only LNOx is accounted for in the OMI data sets.
To date, the daily, monthly, and seasonally occurring flash rates taken from the raw WWLLN data have been plotted on a global map. Comparison between the OTD/LIS data and WWLLN data is progressing to determine flash detection efficiency. WWLLN data is also being compared to the National Lightning Detection Network (NLDN) data to further assess detection efficiency over the United States.
Fig. 1 –