X5.0 solar flare (R3 Strong Radio Blackout) from NOAA/SWPC Region 3536, which occurred on 12/31/23. The flare was the largest observed since September 10, 2017, when an X8.2 flare occurred. Each sunspot is about the same size as the diameter of Earth, or even larger. (Image credit: NOAA Satellites)
While many cities and towns across the globe ended 2023 with fireworks, the sun was busy producing some excitement of its own —an X5 solar flare. This was the largest solar flare observed by NOAA’s Space Weather Prediction Center (SWPC) since 2017.
As we approach the peak of Solar Cycle 25, we should expect to see more sunspots, each of which is a region of intense magnetic activity capable of producing solar flares and coronal mass ejections, or CMEs. This period of elevated activity can last up to several years, with impactful space weather events possible in 2024.
Solar flares emit radiation, mostly in the form of ultraviolet light and X-rays. The radiation reaches the sunlit side of Earth within 8 minutes, traveling at the speed of light. According to the SWPC, these energetic blasts can interfere with radio signals, which is what happened after a strong solar flare briefly interrupted aircraft communications on December 14, 2023.
Some flares are accompanied by CMEs, which are highly-charged bubbles of the sun’s plasma emerging from the sun’s outer atmosphere, known as the corona. As this bubble radiates outward, it carries the sun’s magnetic field with it, taking between 15 hours and a few days to close the gap between the sun and Earth. A CME can collide with Earth’s magnetosphere, the barrier that protects us from the harshest impacts of space weather. It is this collision between a CME and Earth’s magnetosphere that produces geomagnetic storms.
This is the type of space weather that we can see! The beautiful Aurora Borealis, or Northern Lights, is produced by electrons from geomagnetic storms colliding with Earth’s atmosphere. The SWPC produces an Aurora forecast, which will come in handy the next time a CME is predicted to impact Earth.
On April 8, 2024, a total solar eclipse will give us a rare chance to see the sun’s magnificent corona. Two solar phenomena to look for: Prominences, or large arcs of plasma suspended above the sun’s surface; and if it happens during totality, we could see a CME in real time.
The SWPC is the official source for space weather forecasts for the U.S.. Visit the SWPC website for the aurora forecast, videos of recent CMEs, information about space weather impacts and more.
