Prepare for a celestial spectacle as the stunning aurora borealis is set to illuminate the northern Chinese mainland this weekend. The Chinese Meteorological Administration's National Center for Space Weather forecasts solar activity to be at moderate to high levels from Friday, with a possibility of M-class or larger solar flares.
Severe geomagnetic storms are anticipated due to coronal mass ejections (CMEs), with disturbed ionosphere levels expected on October 11 and 12, returning to calm on October 13. Aurora enthusiasts are reminded that from the evening of October 10, particularly in the early morning hours up to October 12, there's a chance to observe prominent auroras in the northern Chinese mainland. Some regions may even witness vibrant red and green composite auroras.
What is a geomagnetic storm?
A geomagnetic storm occurs when a coronal mass ejection from the sun releases billions of tonnes of solar material at high speeds. This material carries substantial kinetic and magnetic energy, which, upon reaching Earth, can alter the geomagnetic field's direction and strength, resulting in a geomagnetic storm.
Why have geomagnetic storms been more frequent in recent years?
The increase in geomagnetic storms is linked to the intensification of solar activity since the onset of solar cycle 25 in December 2019. This cycle has seen a surge in X-class flares, solar proton events, and strong geomagnetic storms, surpassing the activity levels of the previous cycle. Additionally, advancements in the Chinese mainland's space weather monitoring network have enhanced the accuracy of forecasts, allowing for better predictions of active periods.
How are auroras generated?
Auroras are the mesmerizing \"by-products\" of geomagnetic storms. When coronal mass ejections reach Earth, some of their energy infiltrates the atmosphere near the poles, guided by the Earth's magnetic field. Charged particles collide with atmospheric atoms and molecules 100 to 400 kilometers above the ground, transferring energy to their outer electrons. This energy is then rapidly released as the stunning lights known as auroras.
Reference(s):
cgtn.com
