Solar Coronal Hole

CORONAL HOLE: A hole in the sun’s atmosphere–a “coronal hole”–has opened up and it is spewing solar wind into space. NASA’s Solar Dynamics Observatory photographed the UV-dark gap during the early hours of May 29th:

Coronal holes are places where the sun’s magnetic field spreads apart and allows solar wind to escape. A windy stream of plasma flowing from this particular hole should reach Earth on June 2-3. The impact could spark geomagnetic storms and auroras around the poles


Solar Winds — Purple Skies

PURPLE SKIES: Earth is entering a high-speed solar wind stream, and this is causing geomagnetic activity at high latitudes. First contact with the stream on May 22nd turned the sky over Cumbria, United Kingdom, deep purple:

“The sky was bright because of twilight, but we could still see these faint auroras,” says photographer Jon Cooper.

So far the solar wind has not caused a full-fledged geomagnetic storm, but this could change during the next 24 hours. NOAA forecasters estimate a 15% to 20% chance of storms around the poles as the solar wind continues to blow


Coronal Hole Ejections

CORONAL HOLE: A dark hole in the sun’s atmosphere (a ‘coronal hole’) is spewing a stream of solar wind toward Earth. The impact of the stream, expected on May 9-11, could add to the effect of the incoming CMEs, boosting the chances of strong geomagnetic activity later this week. NASA’s Solar Dynamics Observatory took this picture of the opening on May 8th:

Coronal holes are places where the sun’s global magnetic field opens up and allows some of the sun’s atmosphere to escape. The outflow of gas is the solar wind. NOAA forecasters estimate a 40% chance of geomagnetic activity on May 9-10 when the stream arrives (along with the CMEs of May 7th).


Double Coronal Hole

DOUBLE CORONAL HOLE: A double-barreled hole has opened up in the sun’s atmosphere and it is spewing a split-stream of solar wind toward Earth. NASA’s Solar Dynamics Observatory captured this composite UV image of the double coronal hole on August 20th:

Sky watchers should be alert for auroras when the solar wind arrives on August 22-24. NOAA forecasters estimate a 35% to 50% chance of high-latitude geomagnetic activity