Northern Lights: Here's Where You Could See The Aurora Borealis Tonight
What was significant about the mid-May geomagnetic storm in relation to the northern lights?
The mid-May geomagnetic storm was significant because it brought the northern lights throughout the continental U.S., in what scientists dubbed a "potentially historic event." This occurred during a time when the northern lights are typically best viewed between September and April, during seasonal equinoxes. The storm prompted a warning from the National Oceanic and Atmospheric Administration, the first of its kind in nearly two decades.
What are the northern lights and what causes them to appear?
The Northern Lights, or aurora borealis, are a natural light display in the sky predominantly seen in high-latitude regions around the Arctic and Antarctic6. They appear as curtains, rays, spirals, or dynamic flickers covering the sky. The lights are caused by disturbances in the Earth's magnetosphere due to the solar wind. These disturbances alter the trajectories of charged particles in the magnetospheric plasma, which then precipitate into the upper atmosphere, ionizing and exciting atmospheric constituents to emit light of varying colors and complexity.
Why are the northern lights typically best viewed between September and April?
The northern lights, or aurora borealis, are best viewed between September and April due to the extended hours of darkness in the regions near the Arctic Circle during this period. The Earth's tilt on its axis causes the Arctic to experience long, dark nights during the winter months, providing a dark backdrop for the aurora to be more easily visible1. Additionally, solar activity, which is responsible for the auroral displays, tends to follow an 11-year cycle, with increased activity typically occurring during the months of September to April. These factors combined make this period the optimal time for viewing the northern lights.