Last week we had the EMIC (ElectroMagnetic Ion Cyclotron) wave workshop at the University of New Hampshire. It was really a great conference and fun to see many from the field. EMIC waves are often observed both in the magnetosphere by satellites but also on the ground with magnetometers both in the Arctic and Antarctic. Now you might be wondering why we might have had a workshop fully dedicated to just this one type of wave. These waves can at times act as a large source of loss for the radiation belts, but they don't always seem to. Hopefully through the collaborations set up by this workshop, we'll be able to better answer not just why they are some times important and not other times, but when are they important.
As I have stated in past posts, we're very interested in understanding the dynamics of the Earth's Van Allen radiation belts as they can affect both humans and our technology here on Earth. Understanding and predicting when radiation belt particles will be lost from space and into our atmosphere is an active on going area of research. There are many different processes which can affect the radiation belts, but scientists still argue over which ones are the most important, which ones are most geo-effective (the ones which are most likely to affect our technology), and when the different loss processes are relevant. For instance EMIC waves are often found to occur during geomagnetic storms, but not during substorms. Both of these space weather events can damage satellites so it's important to understand the differences between these two types of weather. It's kind of like trying to understand the similarities and differences between tornadoes and hurricanes.
There was a kind of fun article about the "scary" Halloween storm which occurred in 2003 in the Washington Post. In the last couple of years there have been a number of similar solar flares, but thankfully they have all been directed away from the Earth. However this is a good example of why we are trying to understand the radiation belts. If we know how they will respond to such a large storm (or even smaller ones) we can tell satellite operators to turn the satellites off. This will help protect the satellites during the storm, kind of like putting up the storm windows and storing some water and food before a hurricane hits.
When the next big storm hits though don't worry. Perhaps you won't be able to trust your GPS or use your cell phone for awhile, but sit back, relax, and enjoy the beautiful side of all these storms, the Aurora.