22 May 2013


The ongoing radiation storm got started on May 22nd when the magnetic canopy of sunspot AR1745 exploded. The blast produced an M5-class solar flare and hurled a magnificent CME over the sun's western limb:
Credit: the Solar and Heliospheric Observatory (SOHO)

The movie of the CME is very "snowy." That is caused by high-energy solar protons striking the CCD camera in SOHO's coronagraph. Each strike produces a brief snow-like speckle in the image. This hailstorm of solar protons is what forecasters mean by "radiation storm."

Although the explosion was not squarely Earth-directed, the CME will likely be geoeffective. The expanding cloud appears set to deliver a glancing blow to Earth's magnetic field on May 24th around 1200 UT. According to NOAA forecast models, the impact will more than double the solar wind plasma density around Earth and boost the solar wind speed to ~600 km/s. High-latitude sky watchers should be alert for auroras.

Solar wind flowing from this coronal hole should reach Earth on May 23-24. 
Credit: SDO/AIA.


VE3WDM said...

It seems the sun is just on time for the CQ WPX contest this weekend. I guess along with high flux and sunspot numbers comes CME"s as well.

EI5IX - PADRAIC said...

That's True Mike, It'll be interesting to see what it does to the bands! I'm hoping to get some Dah Di Dah's out over the weekend in between work breaks so look forward to hearing you over the weekend. Enjoy!