Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Stargazing Solar Activity and Space Weather Update thread

  1. Sep 8, 2017 #21
    Currently from SpaceWeatherLive.com:

    "Current data suggest that there is a decent possibility that aurora can be seen now at middle latitudes

    G4 - Severe geomagnetic storm
    Observed Kp: 9-

    The solar wind speed is currently high (742.6 km/sec.)

    The direction of the interplanetary magnetic field is slightly South (-6.69nT).

    The Disturbance Storm Time index predicts strong storm conditions right now (-118nT)

    The maximum X-ray flux of the past two hours is:

    S1 Space Radiation Storm
    At the moment there is a minor S1 class space radiation storm active. This happens about 50 times in one solar cycle."
  2. Sep 9, 2017 #22
    Another strong M3.79 flare, just a few minutes ago, from sunspot region 2673. So hopes for more aurora in a couple of days (max 3) !
  3. Sep 10, 2017 #23


    User Avatar
    Science Advisor
    Gold Member

    it's not earth bound as the spot group is about to disappear around the limb of the sun :smile:
  4. Sep 10, 2017 #24
    I was afraid of that :sorry: ... . Is that always the case when close to limb, no matter how strong is the flare? Or it depends on the angular distribution of the CME?

    Yesterday (other issue), a few hours after my last post above, I witnessed myself a short-wave band Radio Blackout, which was also announced (by SpaceWeather...) at the time, but I am not sure what the origin was. The whole short-wave band was totally wiped out (for an hour or so, if I am not mistaken).
  5. Sep 10, 2017 #25


    User Avatar
    Science Advisor
    Gold Member

    the size and the way/direction(s) the flare erupts has a direct effect on the CME produced. That said, it isn't totally black and white.
    Flares may or may not produce significant CME's and sometimes a smaller flare say a M2.2 can produce a bigger CME than a M6.1.

    When it comes to flares that are pointing at an angle significantly away from the earth, they tend to have little effect umless they
    produce a "full halo " CME .... You will see the term "full halo" used periodically when describing CME's

  6. Sep 10, 2017 #26
    Thanks Dave! :smile:
  7. Sep 10, 2017 #27
    Just before the culprit 2673 rotated out of view:
    "Latest news
    Sunday, 10 September 2017 - 16:18 UTC
    X8.2 solar flare"

    Currently no named sunspot regions! (may be tomorrow one ...)

    But: (active as we speak)
    "S3 Space Radiation Storm
    At the moment there is a strong S3 class space radiation storm active. This happens about 10 times in one solar cycle.
    (From SpaceWeatherLive.com)
  8. Sep 11, 2017 #28
    Reading about the monster X9.3 event on Sept. 6 got me onto the near hit of the massive CME in 2012. As an IT professional, I'm curious about how much warning we would get if one of these Carrington events was headed straight for us, which apparently has a 12% chance of happening between 2012-2022.

    Edit: Looks like DSCOVR can provide a 15-60 minute early warning from the L1 Lagrangian point.
    Last edited: Sep 11, 2017
  9. Sep 11, 2017 #29


    User Avatar
    Science Advisor
    Gold Member

    the time difference is related to the speed of the CME and these can vary significantly ... 400 to 1500+ km/sec
    over 1000 km/sec is reasonably rare but 700 - 1000 km / sec is quite common for the avg to large CME

    that first link you gave about the CME in 2012 was mostly good, tho there are some total inaccuracies
    like this comment

    this is total garbage .... we have had other space craft orbiting at the L1 Lagrangian point for years
    namely SOHO and more recently the SDO ( Solar Dynamics Observatory)
    they would not have missed the event

  10. Sep 11, 2017 #30
  11. Sep 11, 2017 #31
    Wow, is this flurry of major flares very unusual? Solar warming perhaps? : )
  12. Sep 12, 2017 #32
    I think it's just a final breakout before solar minimum. But rare, indeed!
    Or it may be a random, but normal, fluctuation in the solar cycle.
    Last edited: Sep 12, 2017
  13. Sep 12, 2017 #33


    User Avatar
    Science Advisor
    Gold Member

    So far there hasn't been any warnings relating to that flare. I suspect it is just too far around the limb to be significantly geo-effective

    On the other hand, there has been a warning released for a CME relating to the coronal hole that will probably cause unsettled to active conditions with probability of some auroral activity
  14. Sep 12, 2017 #34
    Here is what I found:
    1. "S2 Solar Radiation Storm
    Infrequent effects on HF radio through polar regions and satellite operations
    " (as we speak)
    2. R2 Radio emission (beginning ~07:29 UTC) [lasting/lasted about an hour or so] ... (I think, because I lost the original alert)
    3. Latest news
    Monday, 11 September 2017 - 16:42 UTC
    X8.2 coronal mass ejection
    4. Latest news
    Monday, 11 September 2017 - 23:01 UTC
    Coronal hole faces Earth

    (Source: SpaceWeatherLive.com and spaceweather.com)

    What do you make of those?
  15. Sep 12, 2017 #35
    Here is what is interesting from the CME link (#3 above):
    A) "Yesterday's X8.2 (R3-strong) solar flare from sunspot region 2673 was one of the most spectacular solar flares we have ever seen. Not only was this the second strongest solar flare of the current solar cycle, it also launched an extremely fast and broad coronal mass ejection. What a way to say goodbye! Let's hope it survives its 2 week journey on the far side of the Sun!

    As a matter of fact, sunspot region 2673 was already behind the western limb when the solar flare erupted. We will never know for sure but this event might have been even stronger than an X8.2 solar flare if sunspot region 2673 was still present on the earth-facing side of the solar disk. You can find more information in yesterday's news article.

    Following the flare, we quickly reached the strong S3 solar radiation storm level which only takes place about 10 times during a 11 year solar cycle. Possible effects of the ongoing S3 solar radiation storm are: degraded HF radio propagation at polar regions and navigation position errors, satellite effects on imaging systems and solar panel currents, significant radiation hazard to astronauts on extra-vehicular activity (EVA) and high-latitude aircraft passengers.

    B) "The flanks of a coronal mass ejection are always a bit slower than the bulk so we can't go with 2.700km/s but the transit time should still be around one and a half day or about 36 to 40 hours (calculated with SARM) which puts the expected impact time of this coronal mass ejection at 06:00 UTC on 12 September 2017 with a plus/minus of 6 hours. Note that the NOAA SWPC has a much later impact time late on September 13 which was a surprise to us.

    It remains to be seen how strong the magnetic field will be at impact as this is a value that can disappoint with these glancing blows but a distinct increase in the solar wind speed up to at least 700km/s should be possible. A minor G1 geomagnetic storm will be possible after the plasma cloud arrives.

    Personaly I think that chances for aurora are slim this time.
  16. Sep 12, 2017 #36
    "Latest news
    Tuesday, 12 September 2017 - 19:54 UTC
    Coronal mass ejection arrival"

    G1 minor Geomagnetic storm warning was issued the last hour or so (Kp 5 - Threshold reached 19:49 UTC)

    + (quoting from spaceweather.com):

    "THE CME HAS ARRIVED: Arriving earlier than expected, the flank of a CME hit Earth's magnetic field on Sept. 12th (20:00 UT), and the impact has sparked a minor G1-class geomagnetic storm. NOAA forecasters say the storm could intensify to G2-class on Sept. 13th. If so, auroras in the USA could appear as low as New York to Wisconsin to Washington state. This is the CME that was hurled obliquely toward us by the X8-flare of Sept. 10th."

    + Edit (report highlights added from spaceweatherlive.com):

    Current data suggest that it is not possible to see aurora now at middle latitudes

    G2 - Moderate geomagnetic storm expected
    The observed Kp index is 5- but the predicted K-indice of 6- indicates that stronger geomagnetic conditions might occur at this moment.

    The solar wind speed is currently moderately high (575.7 km/sec.)

    The strength of the interplanetary magnetic field is moderate (10.27nT), the direction is North(1.8nT).

    S1 Solar Radiation Storm
    Minor impacts on HF radio through polar regions
    Last edited: Sep 12, 2017
  17. Sep 12, 2017 #37
    Moderate G2 Geomagnetic storm (Kp 6), Threshold reached 2:59UTC.
  18. Sep 14, 2017 #38
    So finally, Tue 12 Sept (and yesterday Wed. etc.), AR2673 did leave behind a last small aurora activity for us [due to its latest close to limb X8.2 monster flare - see earlier above]. (See https://www.physicsforums.com/threads/for-those-aurora-chasers-a-heads-up.923833/page-2#post-5840153)

    What a nice way to say goodbuy! May be it will return alive if it survives the approximately 2weeks rotation around our star. But for now the "devil" is gone! ...
    Here is a current view of the Sun (relatively quiet - just one group 2680 [current 2 stretch spotless days]):

    But currently we have active geomagnetic conditions due to the other factor: the recent coronal hole (see earlier above). [See upcoming post to the above @davenn 's aurora thread]

    Here is also a review video for 2673:
    Last edited: Sep 14, 2017
  19. Sep 16, 2017 #39
    G2 - Moderate geomagnetic storm
    Observed Kp: 6-

    The solar wind speed is currently high (714.1 km/sec.)

    Current data suggest that it is not possible to see aurora now at middle latitudes
  20. Sep 18, 2017 #40
    The earth is still inside a stream of solar wind flowing from this northern coronal hole:
    (Credit: NASA/SDO)

    As a result we've been having, almost continuously since the last post/update, active geomagnetic conditions (max Kp 4-6 per case). The last one today, Sept. 18, which reached threshold 08:56 UTC, and it was a G1 (Kp5) minor geomagnetic storm.

    Quiet right now (Kp 2). Only one group of spots AR2680 etc.

    And news (from a source that I haven't confirmed yet): AR2673 is still active with recent significant eruptions on the farside ... and due to return around Sept 23. We're waiting! ...
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?