The aurora borealis, commonly known as the Northern Lights, is currently exhibiting increased activity, with potential visibility extending further south than usual. Forecasts indicate that displays may be visible in and across several states and even in Britain. This heightened activity is driven by ongoing surges in solar activity.
Understanding the Aurora and Current Forecasts
The aurora borealis is a natural light display in the sky, predominantly seen in the high-latitude regions (around the Arctic and Antarctic). It’s caused by charged particles from the sun colliding with atoms in the Earth’s atmosphere. These collisions release energy in the form of light. The color of the aurora depends on the type of atom being excited and the altitude of the collision; green is the most common color, but reds and purples can also appear during intense events.
The Space Weather Prediction Center (SWPC) provides forecasts and visualizations of the aurora’s potential visibility. Their “Aurora Viewline” product predicts the intensity and location of the aurora over North America. This prediction is based on the OVATION (Oval Variation, Assessment, Tracking, Intensity, and Online Nowcasting) model, developed at the Johns Hopkins University Applied Physics Laboratory. The model uses the maximum forecast geomagnetic activity (Kp) between 6pm and 6am US Central Time to determine the aurora’s reach.
According to the SWPC, the aurora’s brightness and location are typically shown as a green oval centered on Earth’s magnetic pole. This oval turns red when the aurora is forecast to be more intense. The aurora can be observed from as much as 1000 km away from the oval when conditions are favorable. A short-term forecast (~30 minutes) and the last 24 hours of activity are available on the Aurora – 30 Minute Forecast page, and the SWPC’s new Aurora Dashboard provides a centralized hub for space weather information.
Recent and Projected Geomagnetic Activity
Recent geomagnetic activity has been relatively low, with a Kp index of 2 recorded for , , and . However, the forecast indicates an increase in activity over the coming days. The Geophysical Institute at the University of Alaska Fairbanks predicts a Kp index of 3 for through . A significant jump to a Kp of 5 is predicted for , followed by Kp values of 4 for several days thereafter ( – ).
The Kp index is a global geomagnetic disturbance index, ranging from 0 to 9. Higher values indicate greater geomagnetic activity and a wider potential visibility of the aurora. A Kp of 3 is considered “quiet” aurora activity, while a Kp of 5 is considered “moderate.” A Kp of 7 is considered “active,” and a Kp of 9 is considered “very active.”
Why is the Aurora Visible Further South?
The recent increased visibility of the aurora at lower latitudes, including reports from Britain, is directly linked to heightened solar activity. When the sun is more active, it emits more charged particles, leading to stronger geomagnetic storms. These storms compress the Earth’s magnetosphere, allowing the aurora to expand southward. The BBC reports that This represents the reason for the recent sightings further south than usual.
Viewing Tips and Resources
To view the aurora, clear skies and a dark location away from light pollution are essential. The aurora is not visible during daylight hours and is best observed shortly after sunset or before sunrise. While the aurora doesn’t need to be directly overhead, brighter displays can be seen from considerable distances.
Several resources are available for tracking the aurora and planning viewing opportunities:
- SWPC Aurora Dashboard: https://www.swpc.noaa.gov/communities/aurora-dashboard-experimental
- SWPC Aurora Viewline: https://www.swpc.noaa.gov/products/aurora-viewline-tonight-and-tomorrow-night-experimental
- Geophysical Institute Aurora Forecast: https://www.gi.alaska.edu/monitors/aurora-forecast
The increased solar activity and resulting geomagnetic disturbances offer a unique opportunity to witness the aurora borealis from a wider range of locations. The coming days, particularly around , are expected to provide particularly favorable viewing conditions.
