GEOMAGNETIC STORM WATCH (G2): Geomagnetic storms are possible on Aug. 1st, Tuesday, when a CME is expected to hit Earth’s magnetic field. Minor G1-class storms are likely with a chance of escalating to category G2. The CME was hurled almost directly toward Earth by the eruption of a magnetic filament in the sun’s northern hemisphere on July 28th. Aurora alerts: SMS Text
PROTONS ARE *STILL* HITTING EARTH’S ATMOSPHERE: For the second day in a row, energetic protons from the sun are raining down on Earth’s atmosphere. This is called a “radiation storm” (S1-class), and it was caused by a magnificent eruption on July 28th.
The blast site was hidden from view just behind the sun’s northwestern limb. Earth-orbiting satellites registered an M4-class solar flare, but the underlying explosion was stronger. It was probably an X-flare partially eclipsed by the edge of the sun.
How can a sunspot not facing Earth send so many protons in our direction? The answer is “the Parker spiral.” Take a look. As the sun spins, its magnetic field spirals like water flowing from a twirling lawn sprinkler. Lines of magnetic force emerging from behind the sun’s northwestern limb (where the explosion happened) spiral back and make a direct connection to Earth. It’s a superhighway for energetic protons.
This radiation storm looks like it will continue at S1 levels for at least one more day. Its main effect is a polar cap absorption event (PCA) inside the Arctic Circle. Right now, shortwave radios around the north pole aren’t working very well. This global map shows which frequencies are most affected.
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