Royal Astronomical Society Press Release
RAS PN 10/32 (NAM 17) 14-Apr-2010
Scientists from the University of Leicester have used observations from NASA’s STEREO and ACE satellites to come up with more accurate predictions of when blasts of solar wind will reach Earth, Venus and Mars. Anthony Williams will present the results at the RAS National Astronomy Meeting in Glasgow on Wednesday 14th April.
We have recently been experiencing an unusually quiet and long-lasting solar minimum, and solar storms caused by Coronal Mass Ejections have been scarce. Despite this, high pressure pulses of solar wind, called Coronal Interaction Regions (CIRs) have been keeping the space weather unpredictable.
CIRs arise when fast moving solar wind particles gushing out of a coronal hole catch a slower flow ahead and the plasma becomes compressed. As the CIRs reach the upper layers of planetary atmospheres, they can cause high levels of activity in the ionosphere. To date, predictions when CIR events will arrive at planets have been flawed, in that observations of the features close to the Sun underestimate the speed that they are moving by the time they cross Earth’s orbit.