Mittwoch, 12. August 2015 - 21:42 Uhr
SPRITES ABOVE HURRICANE HILDA: On August 10th, the National Weather Service reported an intense outburst of lightning from Hurricane Hilda in the Pacific Ocean. Steve Cullen lives in Waikoloa, Hawaii, where the storm is heading, and when he heard the report he had an idea. Cullen explains: "I wondered if the storm was close enough to be captured by the Canada France Hawaii Telescope CloudCam atop Maunakea. After sunset I logged on to the CloudCam site to check the most recent two-hour timelapse loop, and sure enough, WE HAD SPRITES!!!" Here are some frames from the video:
Sprites are a strange and beautiful form of lightning that shoot up from the tops of electrical storms. They reach all the way up to the edge of space alongside meteors, auroras, and noctilucent clouds. Some researchers believe cosmic rays help trigger sprites, but this is controversial. In short, sprites are a true space weather phenomenon.
As awareness of sprites has increased in recent years, photographers have started to catch them dancing atop ordinary thunderstorms on a regular basis: photo gallery. Seeing sprites above a hurricane, however, is rare. Most hurricanes don't even have regular lightning because the storms lack a key ingredient for electrical activity: vertical winds. (For more information read the Science@NASA article "Electric Hurricanes" by Patrick Barry and Dr.Tony Phillips.) Clearly, Hurricane Hilda is not a typical storm.
Stay tuned for more observations of Hilda's cloudtops as it approaches Hawaii.