Solar-terrestrial indices for 23 February follow.
Solar flux 173 and estimated planetary A-index 3.
The estimated planetary K-index at 1200 UTC on 24 February was 1.67.
Space weather for the past 24 hours has been minor.
Radio blackouts reaching the R1 level occurred.
Cue lots of space weather enthusiasts running around with glee!
The flare seems to have peaked at approx X3.2. A major R3 radio blackout is affecting most of Africa, Europe, the Atlantic and South America.
A Type-IV radio emission has started.
The flare appears to originate from the edge of the sun's south-western limb, so any CME would not be earth-directed. A glancing blow is always possible and we await more data.
An M3.2 flare peaked at 13h10 UT 08 Feb causing a minor R1 radio blackout across the mid-Atlantic.
The flare came from AR3576, which is continuing to be very active.
I've fired up my VLF station signal strength plotter (Spectrum Lab and a long-wire antenna plugged direct to the soundcard input*) and recorded the effect of the flare on some of the signals. The biggest dip can be seen on station GBZ (19.6 kHz) located at Anthorn, Cumbria, approx 500km north of my location. The ionosphere's long recovery is also evident.
An extremely active sunspot region, AR3576, is just rotating into Earth's view on the sun's eastern limb. This region is beta-gamma* in configuration and has generated around seven M-class and five C-class flares during the last 16 hours. Six of the seven M-class flares occurred in the last six hours or so. The largest was an M2.7 flare at 22h38 UT 04 Feb. A Type II radio emission began at 21h01 UT 04 Feb.
NOAA has given the region probabilities as follows during the next ~24 hours: C -flare 95%, M 50%, X 10% and a 5% chance of a proton storm.
A moderate solar flare strength M6.8 peaked at 04h38 UT 29 Jan, causing an R2 radio blackout over SE Asia and Australasia. The flare launched a sizable CME* to the north-west, a proton storm which is affecting the polar regions and a 10.8cm radio burst. Two further CMEs were observed a while later departing from the east and south-east limbs.
The effects of the CMEs may affect Earth in a few days.
NB this is a rolling past/future window; this event will have cleared from view in a few days; anyway it's fun to keep an eye on if you're fond of solar activity).
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A major X5.0 solar flare erupted from the east limb of the sun at around 21h50 UT on 31st Dec. This is the largest flare so far of this solar cycle.
The flare produced a blast of X-Rays that immediately hit Earth's dayside, ionizing the ionosphere and blocking radio signals at the D-layer that would normally be propagating up to the higher F-layer and being bounced around the world.
These maps illustrate the effects of the flare on the amateur HF radio bands. The darker browns, purples and blues are lower frequencies 14 MHz and below. Brighter blues, greens and yellows are bands upto and including the 28 MHz band. The 1st map was the 10 min period 21h25 to 21h34 UT, the 2nd for 21h57 to 22h06 UT. It can be seen that most of the bands in use before the flare were wiped out. This lasted for around 30-60 minutes and the bands slowly came back to life (3rd image 22h52 to 23h01 UT) .
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The flare also produced a strong burst of radio noise that started a few minutes before the visible flare, and was detected going up to around 16 GHz! This would have had the power to briefly interrupt satellite and terrestrial communications, including GPS, cell and sat phones.
The lower frequencies were also hit hard with strong noise affecting most of the VHF band.
Solar-terrestrial indices for 24 December follow.
Solar flux 183 and estimated planetary A-index 9.
The estimated planetary K-index at 1200 UTC on 25 December was 0.67.
Space weather for the past 24 hours has been minor.
Radio blackouts reaching the R1 level occurred.
Aurora Alert: CME impact. Mid-latitude aurora is now being reported by amateur radio operators down to ~51°N over Europe. A Geomagnetic storm is in progress.
Solar-terrestrial indices for 15 December follow.
Solar flux 144 and estimated planetary A-index 12.
The estimated planetary K-index at 1200 UTC on 16 December was 1.67.
Space weather for the past 24 hours has been minor.
Solar radiation storms reaching the S1 level occurred.
🌌 "#SpaceWeather is in its infancy, and an international effort is working towards developing a robust forecast system. We are in a race against time ⏱️, since we cannot know when the ‘perfect storm’ may occur – and it seems as if we are overdue a large event."