HR: 14:10h
AN: A33H-03    [Abstracts]
TI: OMI Tropospheric NO2 from Lightning in Observed Convective Events
AU: * Pickering, K E
EM: Kenneth.E.Pickering@nasa.gov
AF: NASA Goddard Space Flight Center, Laboratory for Atmospheres Code 613.3, Greenbelt, MD 20771, United States
AU: Bucsela, E
EM: eric.bucsela@gsfc.nasa.gov
AF: UMBC/GEST, NASA/GSFC, Code 613.3, Greenbelt, MD 20771, United States
AU: Kucsera, T L
EM: tlk@croc.gsfc.nasa.gov
AF: UMBC/GEST, NASA/GSFC, Code 613.3, Greenbelt, MD 20771, United States
AU: Pan, L
EM: liwen@ucar.edu
AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307, United States
AU: Davis, C
EM: cdavis@ucar.edu
AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307, United States
AU: Gleason, J
EM: James.F.Gleason@nasa.gov
AF: NASA Goddard Space Flight Center, Laboratory for Atmospheres Code 613.3, Greenbelt, MD 20771, United States
AU: Levelt, P
EM: Pieternel.Levelt@knmi.nl
AF: Royal Netherlands Meteorological Institute, Box 201, De Bilt, 3730 AE, Netherlands
AB: Lightning is responsible for an estimated 15 percent of total NOx emissions, and is one of the most prominent sources in the upper troposphere. In this study, we present evidence of lightning-generated NO2 (LNO2) using data from the Ozone Monitoring Instrument (OMI), which has observed tropospheric NO2 since its launch in 2004. Although LNO2 has been also reported in previous satellite studies from the Global Ozone Monitoring Experiment (GOME) and SCIAMACHY, OMI is better suited for such measurements by virtue of its higher spatial resolution and daily global coverage. We will present data clearly showing the LNO2 signal in the OMI tropospheric NO2 product on two days over and downwind of specific convective systems in the US Midwest. Gridded monthly mean tropospheric NO2 data are subtracted from the daily gridded data to obtain the presumed LNO2 signal. Observed cloud-to-ground (CG) lightning flashes from the National Lightning Detection Network (NLDN) were counted along middle and upper tropospheric back trajectories that were run from the regions containing the LNO2 signal. A vertically-weighted average number of upwind CG flashes was obtained using a profile of LNOx mass obtained from a series of midlatitude cloud-resolved storm chemistry simulations. The number of CG flashes was scaled up to total flashes (intracloud (IC) flashes plus CG) using a climatological IC/CG ratio. The number of moles of LNOx in the region considered was estimated by assuming that LNO2 is 30 percent of LNOx. This value was divided by the number of upwind flashes to obtain an average estimate of the number of moles produced per flash. Results yield values in the range obtained through other estimation techniques (e.g., aircraft measurements, models). We will also present a similar analysis over northern Australia during the SCOUT-O3/ACTIVE field campaigns in November and December 2005, in which we will compare the OMI LNOx signals with aircraft observations from the storm anvils.
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 3324 Lightning
DE: 3360 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting