Enhanced Positive Cloud-to-Ground Lightning in Thunderstorms Ingesting Smoke from Fires
Walter A. Lyons,
*
Thomas E. Nelson,
Earle
R. Williams,
John A. Cramer,
Tommy R. Turner
Smoke from forest fires in southern Mexico was advected into the
U.S. southern plains from April to June 1998. Cloud-to-ground lightning
(CG) flash data from the National Lightning Detection Network matched
against satellite-mapped aerosol plumes imply that thunderstorms
forming in smoke-contaminated air masses generated large amounts of
lightning with positive polarity (+CGs). During 2 months, nearly half a
million flashes in the southern plains exhibited +CG percentages that
were triple the climatological norm. The peak currents in these +CGs
were double the expected value. These thunderstorms also produced
abnormally high numbers of mesospheric optical sprites.
W. A. Lyons and T. E. Nelson, FMA Research Inc., Yucca
Ridge Field Station, Fort Collins, CO 80524, USA. E. R. Williams, Parsons Laboratory, Massachusetts Institute of Technology,
Cambridge, MA 02139, USA. J. A. Cramer and T. R. Turner,
Global Atmospherics Inc., Tucson, AZ 85706, USA.
*
To whom correspondence should be addressed.
