Pulsating Aurora --Journal of Geophysical Research, scientists describe

Pulsating Aurora

Though humans have been seeing auroras for thousands of years, we have only recently begun to understand what causes them. Thanks to a lucky conjunction of two satellites, a ground-based array of all-sky cameras, and some spectacular aurora borealis, researchers have uncovered evidence for an unexpected role that electrons have in creating the dancing auroras.

In a new report published in the Journal of Geophysical Research, scientists describe comparing ground-based videos of pulsating auroras — a certain type of aurora that appears as patches of brightness regularly flickering on and off—with satellite measurements of the numbers and energies of electrons raining down towards the surface from inside Earth’s magnetic bubble, the magnetosphere. The team found something unexpected: A drop in the number of low-energy electrons, long thought to have little or no effect, corresponds with especially fast changes in the shape and structure of pulsating auroras.

This image of a colorful aurora was taken in Delta Junction, Alaska, on April 10, 2015. All auroras are created by energetic electrons, which rain down from Earth’s magnetic bubble and interact with particles in the upper atmosphere to create glowing lights that stretch across the sky.

Read more about the study at
http://go.nasa.gov/1RyHbNL

See aurora imagery from space at
http://go.nasa.gov/1RyHbNN