X-Flare - Earth Facing

UPDATE, 3:30 p.m.: NOAA’s Space Weather Prediction Center (SWPC) just posted the following:

The R3 (Strong) Radio Blackout today at 12:49 EDT (1649 UTC) was accompanied by an earth-directed CME. Hampered by limited observations of the event, SWPC forecasters are now anticipating the passage of the [coronal mass ejection] around 1:00 a.m. EDT, Saturday, July 14. G1 (minor) Geomagnetic Storm activity is expected to then ensue through the rest of the day.

In short, NOAA is predicting minor effects from this space weather event - no major impacts on the power grid or satellites anticipated - although we remind you forecasting space weather is difficult and surprises are possible. Sky watchers in northern U.S. (and high latitudes) may have an opportunity to see aurora late Friday night into early Saturday morning.

Original story below . . .

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.
NASA's Solar Dynamics Observatory recorded a flash of extreme ultraviolet radiation from the blast site.



The UV and X-ray pulse from the flare will have partially ionized Earth's upper atmosphere on the dayside of our planet, disturbing the normal propagation of radio signals. Watch the Realtime Space Weather Gallery for possible reports of sudden ionospheric disturbances and other effects.

Active Geomagnetic Activity Due at Any Time

The first interplanetary shock, driven by the CME from Sunday, is expected any time. Soon thereafter, the shock from Monday evening's R3/CME is due. Look for G1-G2 (and maybe periods of G3 if the following shock compresses and enhances the CME magnetic field). Geomagnetic storming should persist 24- 48 hours. Back at the Sun, Region 1158 is still hot and fast-growing, Region 1161 is producing small flares.

Propagation Alert: Will it hit Earth?

On August 1, 2010, the Solar Dynamics Observatory (SDO) observed a beautiful prominence eruption that may hit Earth and cause a geomagnetic storm. As the solar cycle progresses and the Sun becomes more active there will be many more opportunities to observe the causes of space weather. Want to see what happens? Follow the event at spaceweather.com.

And from the Spaceweather website:

On August 1st, the entire Earth-facing side of the sun erupted in a tumult of activity. There was a C3-class solar flare, a solar tsunami, multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more.

High-latitude sky watchers should be alert for auroras tonight. One and possibly two coronal mass ejections (CMEs) are heading toward Earth, propelled by the solar eruptions of August 1st (see below). NOAA forecasters estimate a 10% chance of major geomagnetic storms and a 45% chance of at least some geomagnetic activity when the clouds arrive on August 3rd and 4th.

And finally this report from our good friend Tomas Hood

At approximately 0855 UTC on August 1, 2010, a C3.2 magnitude soft X-ray flare erupted from NOAA Active Sunspot Region 11092 (1092).

At nearly the same time, a massive filament eruption occurred. Prior to the filament's eruption, NASA's Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) instruments revealed an enormous plasma filament stretching across the sun's northern hemisphere. When the solar shock wave triggered by the C3.2-class X-ray explosion plowed through this filament, it appears to have caused the filament to erupt, sending out a huge plasma cloud (a coronal mass ejection, or CME).

A shock wave can be seen emerging from the origin of the X-ray flare and sweeping across the sun's northern hemisphere into the filament field. The impact of this shock wave may well have propelled the filament into space. The movies (see links, below) seem to support the conclusion that both eruptions, occurring together, are linked, despite the approximately 400,000 kilometer distance between the flare and the filament eruption. How can this be? While we cannot always see the magnetic field lines between solar features (magnetic field lines are not visible unless there is plasma trapped along these field lines), we can assume from this event
that huge connecting field lines existed between the sunspot region and the filament in the sun's northern hemisphere.

This is an amazing event. A complex series of eruptions involving most of the visible surface of the sun has occurred, ejecting plasma toward the Earth. This coronal mass ejection (CME) rides the solar wind. Depending on the speed of the solar wind and the ejected plasma, this cloud will reach Earth's magnetosphere sometime between August 3 and August 5. High-latitude sky watchers should be alert for auroras. Radio communications by way of the ionosphere may become degraded soon after the CME arrives, and the degraded conditions may last for up to three days.

First view at the 304-Angstrom wavelength by SDO/AIA:
http://www.youtube.com/watch?v=VyaqxKkSCpU

Second view at the 171-Angstrom wavelength by SDO/AIA:
http://www.youtube.com/watch?v=HW_-yQY6YlA

Source: SDO/AIA

73 de NW7US, Tomas David Hood ( http://tomas-david-hood.com/ )

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Propagation Alert: Will it hit Earth?