Cir - Blog Posts

"CIRs are transition zones between fast- and slow-moving streams of solar wind. They contain magnetic fields and shock waves akin to those of CMEs. While CMEs require some sort of explosion on the sun, CIRs do not. They form gently from the sandwiching of solar wind streams--no solar flare required.

The arrival of the CIR on March 8th immediately caused a G1-class (Minor) storm, intensifying to category G2 (Moderate) on March 9th. Sky watchers in Iceland, Canada and multiple US states from New York to Utah saw the geomagnetic glow.

A fast-moving solar wind stream has arrived on the heels of the CIR. This is the same stream that created the CIR in the first place by compressing a region of slower solar wind ahead of it. Blowing almost 600 km/s, the fast stream could cause additional category G1 (Minor) storms on March 10th.. "