A big coronal gap within the solar’s environment is at the moment dealing with Earth, sending a blast of high-speed photo voltaic wind our manner that would set off geomagnetic storms and auroras this weekend.
The quick photo voltaic wind stream is predicted to reach late Saturday into Sunday (Oct. 11-12), in accordance with house climate forecasters from each NOAA’s Space Weather Prediction Center and the U.K. Met Office. Geomagnetic exercise may begin selecting up late Oct. 11, with the highest activity slated for between 5 a.m. and 5 p.m. EDT (0900-1700 GMT) on Oct. 12.
If the predicted minor (G1) geomagnetic storm conditions are reached on Oct. 12, auroras could be visible as far south as northern Michigan and Maine, according to NOAA’s G-scale, which charges the power of those disturbances. But given the time of 12 months, simply previous the latest autumn equinox, even a small bump in exercise may have a much bigger affect and enhance the probabilities of extra widespread auroras this weekend.
This is not the primary time we have seen this specific coronal gap, although it seems to be somewhat completely different. It’s the identical function that we noticed final month, which took the form of a butterfly or a chicken. Coronal holes can persist for months, reappearing each 27 days or in order the solar completes one photo voltaic rotation.
Coronal holes are areas the place the solar’s magnetic subject opens up, permitting photo voltaic wind to stream extra freely into house. When this photo voltaic wind reaches Earth, it interacts with our planet’s magnetic subject, or magnetosphere, and a few of these energetic particles are guided down magnetic subject traces towards the poles. As they collide with atoms and molecules excessive in Earth’s environment, largely oxygen and nitrogen, they launch power as mild, creating the glowing curtains we all know because the aurora.
Seasonal ‘bump’ in auroras
This weekend’s timing is good for aurora chasers as around the autumn equinox, Earth’s tilt lines up in a way that helps the solar wind connect more efficiently with our planet’s magnetic field. This seasonal boost is known as the Russell-McPherron effect.
NOAA’s latest forecast predicts a peak Kp index of 5, which corresponds to minor (G1) geomagnetic storm circumstances. The Kp index is a world scale that measures geomagnetic exercise from 0 (quiet) to 9 (excessive). The larger the quantity, the better the possibility of seeing auroras farther from their normal polar areas.
Space weather forecast
For a full breakdown of what’s happening on the sun, and what to expect from this weekend’s and next week’s space weather, check out the latest forecast from space weather physicist Tamitha Skov: