Differences in Southern and Northern Lights
Birkeland Centre for Space Science | University of Bergen
American Geophysical Union | 2019 Jan 24
For many years, scientists assumed the aurora seen around the north pole was identical to the aurora seen around the south pole. The poles are connected by magnetic field lines and auroral displays are caused by charged particles streaming along these field lines. Because the charged particles follow these field lines, it would make sense that the auroras would be mirror images of each other.Introduction to Asymmetric Geospace ~ Credit: Birkeland Center for Space ScienceClick to play embedded YouTube video.
However, in 2009, scientists discovered aurora can look differently around the north pole and the south pole, including having different shapes and occurring at different locations – a phenomenon called asymmetry.
Now, a new study in the Journal of Geophysical Research: Space Physics, a publication of the American Geophysical Union, explains how this asymmetry comes about and causes the differences in auroral displays near Earth’s poles. The new research finds the differences in aurora are likely caused by squeezing of Earth’s magnetotail — a magnetic tail that extends away from our planet — by the solar wind and the Sun’s magnetic field. ...
Evolution of Asymmetrically Displaced Footpoints During Substorms ~ A. Ohma et al
- Journal of Geophysical Research: Space Physics 123(1):10,030 (Dec 2019) DOI: 10.1029/2018JA025869