Earth Experiences Direct Strike and Intense Geomagnetic Storm, Here's What to Take Note Of
Last night, Earth experienced a direct collision with a shower of electrically charged particles, triggering the spectacular display of the Aurora Borealis.
Although scientists had predicted a minimal Aurora show, they failed to anticipate the spectacle that ensued — a solar flare ejection impacting Earth's atmosphere, provoking a G1 geomagnetic storm.
Electrically Charged Particles
A solar flare emission is a cloud of charged particles that bursts out from the sun, typically following a solar flare, an intense surge of electromagnetic radiation from a sunspot on our star's surface. The Aurora Borealis is brought forth by the solar wind, this stream of charged particles from the sun interacts with Earth’s magnetic field.
Solar flares traverse at the speed of light and augment the solar wind, but do not trigger the Aurora Borealis. The latest solar flares observed on the sun were an M2-class event on Dec. 13 and an M3.1-class on Dec. 15. Subsequently, a solar flare emission was propelled into space, but climate forecasters predicted it would elude Earth today.
Direct Impact
However, SpaceWeather.com reported a direct strike, as the National Oceanic and Atmospheric Administration's Space Weather Prediction Center recorded the incident at 05:19 UTC (00:19 a.m. EST) on Tuesday, Dec. 17.
Shortly afterwards, the Kp index — which serves as a rough gauge of its intensity — reached 5, which translates to a G1-class geomagnetic storm.
These data were recorded when the electrified particles struck the sensors of NOAA’s DSCOVR satellite, which orbits Earth. It measures the solar wind's speed and magnetic intensity, which is pivotal in determining its imminent alteration.
Precise Moment
Prior forecasts had predicted Aurora for approximately four hours later, between approximately 09:00-15:00 UTC on Tuesday, Dec. 17 (4:00 a.m. EST, 3:00 CST, 2:00 MST and 1:00 PST).
The accurate timing of the Aurora displays is challenging to forecast more than a few minutes in advance. DSCOVR offers a warning period of about 15-30 minutes about a space weather event and any ensuing Aurora displays. Aurora watchers are advised to check NOAA’s 30-minute forecast, where the most recent updates are available, and apps like Aurora Now, which deliver real-time alerts as geomagnetic conditions evolve.
Aurora Visibility
Aurora may have been discernible from some northern-tier and middlewestern U.S. states, such as Washington, northern Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Michigan and Maine in the U.S.
Aurora is commonly seen in polar regions around latitudes of 70 degrees north and south, but during periods of heightened solar activity, the auroral oval may broaden, with displays then visible as low as 25 degrees north and south of the equator.
Wishing you crystal-clear skies and keen eyes.
The direct collision with the charged particles resulted in an unexpectedly vivid display of the northern lights, or Aurora Borealis, last night. Despite an aurora alert and a forecast predicting a minimal show, the activity was significantly more intense due to a solar flare ejection impacting Earth's atmosphere. With the Kp index reaching 5, a G1-class geomagnetic storm was triggered, causing a spectacle that was visible from some northern-tier and middlewestern U.S. states. Unfortunately, the precise moment for aurora sightings was predicted to be around four hours later, but the direct impact occurred earlier than expected.
