In the dark of night on March 23, a dazzling geomagnetic phenomenon shed its light across Canada — and tonight, Canadians can look forward to a minor encore. This instance of aurora borealis, or Northern Lights, is being triggered by intense solar winds, which bring some beautiful disturbance to the Earth's magnetic field.
The U.S. National Oceanic and Atmospheric Administration (NOAA) has a Space Weather Prediction Centre, which sounds extremely cool, and which first predicted a geomagnetic storm on March 22.
Yesterday, March 23, NOAA issued an alert ahead of a strong storm. This March 23 storm was ranked at level G3, which is considered above moderate but not as strong as G4 or G5 storms, which can cause issues in voltage control and wreak some havoc on spacecraft operations, according to the NOAA scale.
A view of the aurora probability across Canada at 11 p.m. EDT on March 23.NOAA
The encore storms coming tonight are predicted to be G1 to G2, on the minor to moderate end of the scale. There's a second measurement system NOAA uses to "characterize the magnitude of geomagnetic storms," called the k-index. A k-index of 1 means geomagnetic calm, and ratings above 5 indicate a geomagnetic storm, according to NOAA.
Last night, during the most intense period of the Northern Lights, the storm peaked at 7.67 between 11 p.m. and 2 a.m. EDT — towards the stronger end of the k-index severity scale.
Tonight, the k-index forecast shows an expected peak of 4.67 at around 11 p.m. to 2 a.m. EDT again. There's a similar peak anticipated on March 26, a little later in the night than on the 23.
During these peaks, Canadians can look to the skies (assuming, and hoping, they're clear of clouds and light pollution) and catch a glimpse of one of the most beautiful natural phenomena on Earth. Happy aurora hunting!
This article's cover image was used for illustrative purposes only.