Examining the Capacity of Hurricane Matthew (2016) in Spawning Halo/Sprite-Producible Lightning Strokes During Its Lifetime

This paper evaluated the overall capability of a hurricane in posing the electromagnetic impact on the high-altitude atmosphere. Oceanic thunderstorms are more efficient in producing negative polarity cloud-to-ground (CG) strokes with large impulse charge moment changes (iCMCs) than continental thunderstorms. As the strongest oceanic thunderstorms, hurricanes’ capability to produce transient luminous events is desired to be examined. Here, we investigated the halo/sprite production of hurricane Matthew (2016) by examining the iCMCs of lightning detected by the World-Wide Lightning Location Network hour by hour at nighttime, based on the ultra-low frequency (ULF) magnetic field of the lightning strokes. Matthew was likely an active halo/sprite producer and produced more than 1,000 halo/sprite producible strokes (H/S strokes) with iCMCs exceeding the threshold (200 C km) for producing halo/sprite. The peak of H/S strokes in the outer rainband lags about one day behind the maximum hurricane strength. Additionally, the absence of positive sprite-producible strokes in the inner core (0–100 km) of Matthew may be attributed to the spiral warm cloud feature, although many negative halos could be produced instead because 112 halo/sprite producible strokes were identified here with 89% being negative. In contrast, the outer rainband exhibits some features of the trailing stratiform region of continental mesoscale convective systems (MCSs) and has been a favorable region of halo/sprite production. Overall, the inner core of Matthew and probably also that of other hurricanes bear the features that make the oceanic thunderstorms a proficient producer of negative halos but not sprites.

Duke Scholars

Author Steven A. Cummer Electrical and Computer Engineering