July 15: e.g. (a few minutes ago) 442.0 & 7.8 at 0620 UT ([i.e.] further rise of speed and new local max, with fluctuations, oscillating ...) [(&) cf. previous post ...]
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DENSE SOLAR WIND SPARKS GEOMAGNETIC UNREST: A dense and strongly magnetized stream of solar wind enveloped Earth
for a few hours on July 14th,
unsettling our planet's magnetic field (Kp=4). So far, no auroras have been reported, probably because of northern summer sunlight. Quiet conditions are expected to resume on July 15th."
Radio bands still Strongly affected again ... .
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Daily Sun: 15 Jul 21
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Both of these sunspots are stable and quiet. Solar flares are unlikely today. Credit: SDO/HMI
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FARSIDE EXPLOSION TOUCHES EARTH: Imagine an explosion on the farside of the sun so powerful, we could feel it here on Earth. It happened on July 13th. The debris emerged in a circular cloud known as a '
halo CME':
Above: The July 13th CME imaged by SOHO coronagraphs
When space weather forecasters first saw this explosion, there was a moment of excitement. It appeared to be heading directly toward Earth. However, data from NASA's STEREO-A spacecraft indicated otherwise. In fact, the CME was heading directly
away from us--a farside event.
Now for the interesting part: Although the explosion occurred on the farside of the sun, it still peppered Earth with high-energy particles. The Energetic and Relativistic Nuclei and Electron (
ERNE) detector onboard SOHO recorded a surge in hard radiation not long after the CME appeared:
How did this radiation reach our planet?
Rami Vainio, a professor of space physics at the University of Turku (Finland), who works with ERNE data says "it’s not possible to answer that question definitely without a detailed analysis involving multiple spacecraft ." However, she speculates that the lift-off of the CME may have created a global shock wave on the farside of the sun. Particles spilling over the edge might have
spiraled toward our planet.
Of particular interest are the green data points in the plot above. These are the most energetic protons ERNE can detect. An uptick in green after the CME indicates unusually "hard" radiation---the kind produced in the leading edge of of a hard-charging CME.
The source of the blast might have been the same sunspot (AR2838) that produced the
first X-flare of Solar Cycle 25 on July 3rd. That sunspot is currently transiting the farside of the sun approximately where the CME came from. Within the next week AR2838 is expected to return--and then, maybe, the real fun begins. Stay tuned!
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(Further Update):
+ Speeds are [almost} constantly dropping [but oscillating in a damping oscillation form ...] after the previous local max above [now 0640 UT ...] ...
E.g. (near, a bit later data): speed 397 (Local min) at 0650 UT ; 422 (local max) at 0710 UT ; and 393.5 & 7.2 at 0745 UT (another, lower, local min of speed, still oscillating ...) ... .
AND 394.9 & 8.6 (local min for speed again, after it had gone above 400 again and just dropped again now ...) just now, minutes ago, at 0856 UT ...
+ with overall (and local) min [seen so far] of 391 (and then it rose again, still oscillating ...), just before closing this live watch at 0901 UT ... ...
Speeds still relatively high though ..., and still geomagnetic unrest etc. and radio interfernce etc. still going on until now, even just now (0928 UT) ... .
P.S. But/And the unrest & phenomenon isn't over yet (despite the drop above). Further watch exibited new increasing tendency for speed since the previous above drop, & with a new significant rise to a locally overall max at 1101 UT of 445.5 & 12.4 ... (and oscillating up and down, but overall still rising, before closing at 1152 UT ... [local and overall so far max of 445.9 & 9.2 at 1129 UT ...]).
P.S.': & New update: dropped to 433.2 ... (local min) & 11.4 (rising density) at 1136 UT ..., and then new local and overall so far max of 451.7 & 7.9 at 1145 UT ... [and then dropped again a bit, still oscillating and still perhaps overall rising ...].
Last values and max (biggest today so far, for speed) seen just before closing at 1205 UT:
457.2 & 7.6.
+ Extensive Radio blackouts right now on AM bands (MW and SW confirmed ...) ...
