Cloud-to-ground lightning enhancement over southern Louisiana.” Geophysical Research Letters 30

lightning data show a significant enhancement of lightning associated with Lake Charles and Baton Rouge, Louisiana. A peak density value of 7 flashes km2 yr1 exists on the western side of the Lake Charles urban area. A comparison of the Louisiana CG flash density distribution with the locations of PM10 (particulate matter less than 10 mm in diameter) sources strongly suggests that pollution plays a key role in lightning enhancement. Urban and sea breeze effects can be neglected. The values of median peak negative current show a sharp difference between land and the Gulf of Mexico; inland values are near 24 kA, while over the Gulf waters immediately offshore are over 30 kA. This observation, along with a relative minimum of negative peak current from the mouth of the Mississippi River southeastward seems to support the hypothesis that the underlying surface characteristics influence the calculated negative current distribution. INDEX TERMS: 330