Tuesday, October 24, 2017
What are red sprites? - NATURAL PHENOMENA
Red sprites are thought to be caused by a rare but intense form of lightning called positive lightning. Whereas most cloud-to-ground lightning has a negative electric charge, positive lightning has a positive charge. It makes up less than 5 percent of lightning, but it packs a punch that's up to 10 times stronger than negative lightning.
That flash of lightning is so strong that it breaks apart molecules in the atmosphere into ions, forming a cold plasma cloud that can be tens of miles across.
The sprites' red color likely comes from those ions smashing into molecules in the air. Similar to the aurora, the charged particles excite nitrogen, hydrogen, and oxygen. The gases eventually settle down and release that energy, some of it in the form of pretty colors.
This photo shows red sprites dancing above a thunderstorm located over southeastern Germany. It was taken just before midnight on August 18, 2017, when the storm was approximately 315 miles (507 km) away from Low Tatras, Slovakia. Red sprites are mysterious forms of lightning that sometimes appear in the upper atmosphere above energetic thunderstorms. Their pinkish-red flashes can only be detected at night (usually only with high-speed cameras) and seem to be linked to particularly strong cloud-to-ground lightning bolts (positive strikes).
Photographer: Ondrej Králik