Solar Tsunami and Radio Burst

SOLAR TSUNAMI AND RADIO BURST: Sunspot AR1875 erupted on Oct. 22nd (21:20 UT), producing an impulsive M4-class solar flare and a loud burst of shortwave radio static. Amateur radio astronomer Thomas Ashcraft of New Mexico was listening at the time of the eruption. "I knew this flare was a strong one by the force of the radio shock front," he says. "It nearly lifted me out of my chair!" Click on the image to hear what emerged from the loudspeaker of his radio telescope:

Advice: Listen to the sound file using stereo headphones. The two channels correspond to two radio frequencies--21 and 28 MHz.

At the time of the flare, Ashcraft was also monitoring the sun using an "H-alpha" solar telescope tuned to the red glow of solar hydrogen. The telescope recorded a tsunami of plasma emerging from the blast site. "It's the shadowy wave that races away to the right of the sunspot," Ashcraft points out.

The tsunami was the source of the radio emission. Shock waves at the leading edge of the tsunami cause plasma instabilities in the sun's atmosphere. Those instabilities, in turn, generate shortwave radio emissions. Ashcraft is a regular listener of the sun and he classifies the Oct. 22nd outburst as "one of the strongest radio blasts of the solar cycle so far. Hopefully it bodes well for future activity.

Source:
http://www.spaceweather.com/