SEPT 2011: Solar explosions continue from active sunspot regions 1302 and 1304. The risk of solar wind damage to the Earth’s magnetic field has risen as a result of sunspot regions rotating toward the Sun’s center making solar flares and CMEs (coronal mass ejections) Earth directed.
The most active region is 1302, and this remains capable of spawning M and X-class flares. Earlier today, region produced an M4.0 flare at 5:03UT. At this time there has not been confirmation coming from coronagraph data which determines of CMEs occurred from this event.
As this active region is now approaching central meridian, any CME event would be Earth-directed. The X-ray background decreased slightly, while the >10MeV proton flux rose slightly above the 10sfu event threshold.
At 12:00UT, a shock was recorded in the solar wind by the ACE spacecraft. The wind speed jumped to 550km/s and the IMF rose to 25nT. As Bz* is currently positive, no major disturbance is currently affecting the Earth magnetosphere but we can expect active to minor storm conditions developing over the coming hours.
Other probably glancing shocks—all associated with the X and M flares of Sept.24 and 25—can be expected over the next 24 hours. Over the next 36 hours, they will keep the geomagnetic activity at unsettled to active levels, with possible additional minor storm periods.
The Sun has a magnetic field which the solar wind can carry throughout the solar system. This is called the Interplanetary Magnetic Field (IMF). Earth also has a magnetic field which forms a bubble around our planet. This is called the Magnetosphere. This bubble deflects the solar wind. Earth’s magnetic field comes into contact with the Sun’s magnetic field in a place called the magnetopause. Here is the catch. Earth’s magnetic field points north.
When the Sun’s magnetic field points south, also known as southward Bz – it may cancel Earth’s magnetic field at point of contact. When the Bz is south the 2 fields link up. This basically opens up a door that may allow energy from the solar wind to reach Earth’s atmosphere.
Earth blasted by one of the most intense geomagnetic storms in years
The sheer force of the geomagnetic storm impacting the planet is seen below, indicating the strongest impact on the planet’s magnetosphere in this simulation by NICT.
The K-Index reached 8 and the solar wind speed doubled with a proton density count that spiked near 10 protons/cm3… ( More )
Aurora watchers in Asia and Europe are most favorably positioned for this event, though it may persist long enough for viewers in North America. The bulk of this recent CME missed the Earth, meaning the storm intensity and duration are less than what they would have been in the case of a direct hit.