Aurora Watch 2012 Forecasts, analysis and sightings for the year.
Posted 25 April 2012 - 00:46
All eyes on the 26th (Thur) as a halo-CME observed on the 23rd is due to impact early in the day, leaving open the possibility of aurora for the UK late evening from prolonged geomagnetic substorm activity as it is quite fast and dense.
SOHO Latest C3 3-day anim (large): http://sohowww.nasco.../current_c3.gif
WSA-ENLIL Solar Environment Model Latest: http://www.swpc.noaa...nlil/cme-based/
Posted 25 April 2012 - 21:47
Update on CME from 4/23/2012 18:09:00 UT. Based on revised heliospheric modeling carried out at NASA GSFC Space Weather Center, it is estimated that the CME may impact the Earth earlier than predicted previously. Simulations indicate that the leading edge of the CME will reach the Earth at the revised arrival time of 04/26/2012 at 12:13 UT (plus minus 7 hours). The roughly estimated expected range of the Kp index is 3-5 (minor). (credit: NASA Goddard Space Weather Center)
Posted 08 May 2012 - 11:22
Also another CME released yesterday in association with a M-class flare and type IV radio burst (type IV are known to confirm strong flares and CMEs). It looks set to impact us full-on sometime on the 10th, and is quite a fast-mover so likely some wobbling of the geomagnetic field. Latest Goddard ENLIL run.
SOHO imagery feed appears to be interrupted, so this event hasn't been confirmed with a LASCO C3 'halo-CME' analysis AFAIK.
Posted 09 May 2012 - 19:29
Posted 18 May 2012 - 13:12
Expected to reach us during the second half of today, though possibly only a glancing blow according to the ENLIL. SWPC have middle latitude probabilities at 35% for active, 25% for minor storm and 10% for major storm conditions. Should calm down tomorrow.
Posted 13 June 2012 - 19:46
Posted 17 June 2012 - 01:43
The reason was a double-impact of CMEs from 0900z onwards today. Albeit in themselves quite weak, there was sufficient increase in solar wind speed and timing of the impacts to compress the magnetosphere significantly - to within geosynchronous satellite orbit just after 21z for a couple of hours. The auroral activity is thus derived from severe wobbling of the magnetic field and the thrust of charged particles into it, rather than the usual favourable magnetic conditions for charge seeping in at the polar cusps. Indeed, the last of the two CMEs had a very northward magnetic component (Bz), so the statistical oval models wouldn't have picked up on this using ACE data. Kp has been estimated at 6 globally, so quite a significant geomagnetic substorm going on!
Attached: POES satellite-derived oval, magntopause standoff distance graph (the compression of the edge of the magnetic field seen tonight), and the GOES satellite magnetometers going mental when they were exposed to the solar wind due to the compression.
Posted 12 July 2012 - 02:17
Attached POES oval, ACE solar wind data for 24hrs, and Kiruna magnetometer reacting.
Little bit late for any views with dawn approaching, and unlikely to be any effects continuing to late tomorrow. Thought I'd post it up as it's the best we've had from what's been a fairly quiet affair recently...
Posted 12 July 2012 - 17:35
X-FLARE! Big sunspot AR1520 unleashed an X1.4-class solar flare on July 12th at 1653 UT. Because the sunspot was directly facing Earth at the time of the blast, this is a geoeffective event. Stay tuned for updates about possible CMEs and radio blackouts.
Posted 13 July 2012 - 13:07
It was also quite a long-duration eruption, with a sustained 'ribbon' flare, at around 2hrs. It's possible that a significant cloud of coronal mass, and a longer than normal period of geomagnetic sub-storm activity is approaching.
Imagery of the eruption and associated flare available here
Solar Dynamics Observatory on youtube: