Major X1.8 solar flare produces Earth-directed CME, impact expected late October 10
A major solar flare measuring X1.8 erupted from Earth-facing Active Region 3848 at 01:56 UTC on October 9, 2024. The event started at 01:25 and ended at 02:43 UTC. A fast-moving full halo coronal mass ejection (CME) was produced during the event, with the impact expected from late October 10 to early on October 11. Solar proton counts started sharply rising at 02:40 UTC and reached S2 – Moderate solar radiation storm levels at 07:30 UTC.
CME produced by X1.8 solar flare on October 9, 2024 with Comet Tsuchinshan-ATLAS. Image credit: NASA/ESA LASCO, SDO/AIA 304, Helioviewer, The Watchers
A significant, long-duration solar flare classified as X1.8 erupted from geoeffective Active Region 3848 at 01:56 UTC on October 9, 2024. The flare produced a fast-moving coronal mass ejection (CME), expected to impact Earth between late October 10 and early October 11. X-class flares are the most intense category, with X1.8 indicating a strong burst of radiation.
A Type II Radio Emission, with an estimated velocity of 5 176 km/s was detected at 01:44 UTC. Type II emissions occur in association with eruptions on the Sun and typically indicate a coronal mass ejection is associated with a flare event.
A Type IV Radio Emission was detected at 01:43 UTC. Type IV emissions occur in association with major eruptions on the Sun and are typically associated with strong coronal mass ejections and solar radiation storms.
Additionally, a 10cm Radio Burst (tenflare) lasting 174 minutes and with a peak flux of 2 700 sfu was detected from 01:36 to 04:0 UTC.
A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.
The CME is expected to impact Earth between late October 10 and early October 11.
Radio frequencies were forecast to be most degraded over the Pacific Ocean at the time of the flare.
Region 3848 Produced an X1.8 flare that peaked at 09/0156 UTC. A subsequent HALO CME was observed and is being analyzed at this time. Preliminary arrival is expected to be late on 10 Oct to early on 11 Oct. Also, note that Comet Tsuchinshan-ATLAS is visible in imagery. pic.twitter.com/7cGF0ylPYd
— NOAA Space Weather Prediction Center (@NWSSWPC) October 9, 2024
Solar proton counts started sharply rising at 02:40 UTC, as detected by NOAA satellites in geostationary orbit around Earth. High-energy particles can reach Earth anywhere from 20 minutes to many hours following the initiating solar event.
S1 – Minor solar radiation storm threshold was reached at 04:40 UTC. S1 radiation storms can have minor impacts on polar HF (high frequency) radio propagation resulting in fades at lower frequencies.
S2 – Moderate solar radiation storm threshold was reached at 07:30 UTC and the counts continued rising. S2 radiation storms occur approximately 25 times per solar cycle.
S2 radiation storms bring a range of potential impacts across biological, satellite, and communication systems. Passengers and crew aboard high-altitude flights over polar regions may experience elevated radiation exposure, though airlines can reroute flights to minimize these risks.
Satellites may experience rare single-event upsets, where electronic components temporarily malfunction due to energetic particles. Additionally, minor disturbances in high-frequency radio communications and navigation systems, particularly in the polar regions, may occur, potentially affecting both aviation and navigation operations reliant on these technologies.
A very interesting observation related to the event was noted by Dr. Tamitha Skov, connecting it with a large number of Starlink outages.
“This X1.8-flare had lots of radio energy at very high frequencies, easily beyond the 12 GHz range. This is where Starlink operates. A look at Down Detector statistics shows a suspiciously large number of outage reports right when the flare hits,” Dr. Skov said.
Update
13:57 UTC on October 9
As a result of this flare, a G4 – Severe or Greater Geomagnetic Storm Watch is in effect for October 10 and 11.
Potential impacts of G4 – Severe geomagnetic storms are primarily expected poleward of 45 degrees Geomagnetic Latitude. Power grids may experience widespread voltage control issues, and protective systems could mistakenly trip key assets, while induced pipeline currents may intensify.
Spacecraft systems could face surface charging, increased drag on low Earth orbit satellites, and issues with tracking and orientation. Satellite navigation (GPS) may be degraded or inoperable for hours, and HF (high frequency) radio propagation could be sporadic or blacked out. Auroras may be visible as far south as Alabama and northern California.
I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.
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