[Bazmundo]

Tony Sales, on 25 February 2012 - 18:43, said:

So do we think the storm conditions will be low for tomorrow evening?

Worth keeping an eye on the 22z updates to the SWPC forecast, as they run the ENLIL-WSA-GONG model several times with more recent data to analyse plane-of-sky speeds, etc. Only the relevant ones are published online. Currently the view is unsettled to active with chances for isolated storms (geomagnetic), but it's still difficult to identify the aurora type until the CME reaches ACE and the rest of the geosatellite enviroment so we can get some real-time analysis. Even then the connection between display type and CME isn't fully understood, as detection and analysis of CMEs is still limited and hence so is forecasting.

Worth being optimistic though, or at least not missing anything.

[Tony Sales]

Bazmundo, on 25 February 2012 - 20:49, said:

Worth keeping an eye on the 22z updates to the SWPC forecast, as they run the ENLIL-WSA-GONG model several times with more recent data to analyse plane-of-sky speeds, etc. Only the relevant ones are published online. Currently the view is unsettled to active with chances for isolated storms (geomagnetic), but it's still difficult to identify the aurora type until the CME reaches ACE and the rest of the geosatellite enviroment so we can get some real-time analysis. Even then the connection between display type and CME isn't fully understood, as detection and analysis of CMEs is still limited and hence so is forecasting.

Worth being optimistic though, or at least not missing anything.

Cheers, I'll be watching

[Dave Hancox]

I see its forecast possible G2 /S2 ( KP6) Solar storm from this on the 26th . http://www.theweathe...-solar-sun.html


Five Solar Eruptions in 2 Days – CME On the Way http://www.nasa.gov/...022512-cme.html

[Bazmundo]

Dave Hancox, on 26 February 2012 - 05:25, said:

I see its forecast possible G2 /S2 ( KP6) Solar storm from this on the 26th . http://www.theweathe...-solar-sun.html

He's not a reliable source IMO Dave, not worth checking with.

[Dave Hancox]

Thanks for the heads up Glyn worth mentioning, shame though. It has been A very quiet event as it turns out.

[Dave Hancox]

Dave Hancox, on 26 February 2012 - 15:15, said:

Thanks for the heads up Glyn worth mentioning, shame though. It has been A very quiet event as it turns out.

That being said and having a look at the latest model forecast for later tonight for impact can only monitor it and see what develops.

http://www.swpc.noaa...nlil/cme-based/

[Bazmundo]

Something's bumped ACE at 21z onwards, initially northward oriented but with a little dip. The enormous increase in density (third graph, logarithmic) in the matter cloud has the ACE plots auto-adjusting. All eyes on the aurora plots even though as yet Kiruna hasn't wobbled too much - could this be too swift and not magnetically biased enough? It should have impacted the ionosphere by now, as ACE only has a lead time of 1 - 1.5hrs.

Ovation Prime isn't online for some reason.

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[Bazmundo]

So far only the initial impact trace signature from most magnetograms although Kiruna is registering more now, as are the GOES satellites. The fluctuations seem enough to stir the aurora plots a little. Density of the passing solar wind is still on the increase, hence so is the dynamic pressure on the magnetosphere as simulated. Attached are two high intensity simulated bowshocks, an hour ago and just now. Might be worth those in the north keeping an eye to the sky while the cloud is still clear and we rotate into midnight, though so far this has been a weaker response than I thought....

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[Bazmundo]

Looks like we've had a disappointing result from this CME as the magnetosphere took the initial force of the dense matter cloud but didn't reverberate nor soak up enough charge to generate aurora as we rotated through the fuller side of the oval. Aurora were observed in Scandinavia, though no surprise there really. In contrast, the middle portion of the CME did have southward magnetic orientations and danced aurora across NWrn N America (as observed by US and Canadian magnetometers between 11-21z), and also across Russia for the aft portion (POES stat oval attached) with a K-5 finale. Likely some of this was down to reverberations in the magnetosphere after the initial compression (attached magnetopause standoff distance, in R_E - Earth radii) and possibly magnetotail reflux as that also responded to an usually pressurised shock, but also noteworthy that the solar wind environment was mainly southward oriented prior so the 'finale' could have been that re-stabilising behind (less likely, as conditions have abruptly returned to 'average' since then).

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[Dave Hancox]

Not what we hoped for but some in Ne Scotland managed to capture it last night. Here's to some stronger displays. http://www.flickr.co...in/photostream/

[Bazmundo]

Dave Hancox, on 28 February 2012 - 08:46, said:

Not what we hoped for but some in Ne Scotland managed to capture it last night. Here's to some stronger displays. http://www.flickr.co...in/photostream/

Looks as though the longevity in this case was possibly down to the magnetosphere wobbling back into equilibrium with additional influx of charge from the returning IMF, and further evidence is mounting for magnetotail reflux being the cause of many post-shock aurora (not specific to this impact, but new research): http://www.scienceda...20228152214.htm

Quote

Egedal had initially proposed a theory to explain this large-scale acceleration of electrons in Earth's magnetotail -- a vast and intense magnetic field swept outward from Earth by the solar wind -- but until the new data was obtained from the computer simulation, "it used to be people said this was a crazy idea," Egedal says. Thanks to the new data, "I don't get that anymore," he says.

Solving the problem required a staggering amount of computer power from one of the world's most advanced supercomputers, at the National Institute for Computational Science at Oak Ridge National Laboratory in Tennessee. The computer, called Kraken, has 112,000 processors working in parallel and consumes as much electricity as a small town. The study used 25,000 of these processors for 11 days to follow the motions of 180 billion simulated particles in space over the course of a magnetic reconnection event, Egedal says. The processing time accumulated gradually, squeezed in during idle time between other tasks. The simulation was performed using a plasma-physics code developed at LANL that rigorously analyzes the evolution of magnetic reconnection.

Egedal explains that as the solar wind stretches Earth's magnetic-field lines, the field stores energy like a rubber band being stretched. When the parallel field lines suddenly reconnect, they release that energy all at once -- like releasing the rubber band. That release of energy is what propels electrons with great energy (tens of thousands of volts) back toward Earth, where they impact the upper atmosphere. This impact is thought, directly or indirectly, to generate the glowing upper-atmosphere plasma called the aurora, producing spectacular displays in the night sky.

[Bazmundo]

Possible glancing blow expected from a CME associated with an M-class flare in the NE quarter of the solar disc yesterday (4th, ~1050z). Plane of sky speed appears to be quite fast and impact is around tomorrow morning (6th). Analysis via imagery is ongoing. The radio burst from the M2 flare disrupted some instruments, so the earliest SOHO C3 image is 1518z (attached), but a quick look at a 'difference' comparison of that and a 1018z image shows the fresh matter outburst (also attached, greyscale) and also that some of it is directed our way. Also attached is a 1225z image from STEREO-Behind showing the outburst of matter to the upper right.

CME event alert and SWPC geomagnetic activity probabilities:

Quote

Event Issue Date: 2012-03-04 15:06:24.0 GMT
CME Arrival Time: 2012-03-06 04:29:07.0 GMT
Arival Time Confidence Level: ± 6 hours
Disturbance Duration: 13 hours
Disturbance Duration Confidence Level: ± 8 hours
Magnetopause Standoff Distance: 5.6 R_e
Tue, 06 Mar 2012 04:29:07 GMT
Tue, 06 Mar 2012 17:29:07 GMT

Geomagnetic Activity Probabilities 05 Mar-07 Mar
A. Middle Latitudes
Active 05/30/15
Minor storm 01/15/05
Major-severe storm 01/01/01
B. High Latitudes
Active 15/35/20
Minor storm 10/25/15
Major-severe storm 01/15/10

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[Bazmundo]

Most recent relevant ENLIL model run for CME detailed in previous post, apologies for quality but the GIFs weigh in a little above 2Mb and need compressing...

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[Bazmundo]

As Dave has noted in the Spaceweather Effects thread, the same active region has unleashed an X-class flare between 04z and 05z this morning, and an ENLIL run at 08z has been posted up: http://www.swpc.noaa...nlil/cme-based/ which tracks a new associated CME along the same path as the previous one (glancing blow).

SOHO wasn't knocked out this time, and saw the matter burst associated with the flare, as did Stereo-B (both attached). Also attached is an SDO AIA composite image of the full disc, with a close-up showing a beautiful eruption from the sunspot AR1429 (prob ten times the size of Earth at least).

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[Bazmundo]

More info from today's CME from Belgium SIDC:

Quote

:Issued: 2012 Mar 05 1326 UTC
:Product: documentation at http://www.sidc.be/products/presto
#--------------------------------------------------------------------#
# FAST WARNING 'PRESTO' MESSAGE from the SIDC (RWC-Belgium)
#--------------------------------------------------------------------#
The X1.1 flare from this morning was accompanied by a full halo CME
that first appeared in the SOHO/LASCO C2 field of view at 04:00 UT and
propagated at a projected plane of the sky speed of around 1300 km/s. We
expect the CME-associated interplanetary disturbance (most probably only
a CME-driven shock due to the source region position close to the limb)
to arrive at the Earth on March 7-8, possibly triggering a minor to
moderate geomagnetic storm. The eruption was associated with a strong
radio flux in the metric range.

To clarify, we're now expecting two CME's in the coming days; the first in the early hours of tomorrow (6th) and another fast shock between Wed and Thu (7-8th).

[Sam Jowett]

AR1429 seems to be sparking away nicely.... there has been a double spiking M1 flare this evening to follow the X1 and M class in the last 36 hours, along with several other high C class flares. The EMF is tilting S a bit already with strong aurora in northern latitudes: http://www.aurorasky.../live-camera/9/ - it seems likely to only get busier in the coming days...

[Bazmundo]

Certainly looks like a plump oval at the moment. The POES site is offline for upgrades, but it would appear the OVATION has a new home and a page dedicated to Europe:

http://helios.swpc.n...ion/Europe.html

[Andrew W]

Is this anything to do with the strange sounds being reported around the world in the sky?

[Dave Hancox]

Bazmundo, on 05 March 2012 - 22:53, said:

Certainly looks like a plump oval at the moment. The POES site is offline for upgrades, but it would appear the OVATION has a new home and a page dedicated to Europe:

http://helios.swpc.n...ion/Europe.html

That is a cracking format.

[Bazmundo]

Andrew W, on 05 March 2012 - 23:05, said:

Is this anything to do with the strange sounds being reported around the world in the sky?

No