The Sun operates on an 11-year cycle, alternating between active and quiet periods. We are currently in a quiet period, with few sunspots on the sun’s surface and fewer solar flares, though the next cycle of activity has begun. It is expected to peak around 2012, bringing lots of sunspots, flares and coronal mass ejections (CMEs). CMEs can interact with the Earth’s magnetosphere, causing problems for satellites, communications, and power grids.
This upcoming active period now looks like it will be more intense than the previous one, which peaked around 2006, some scientists think. The reason is the changes in the sun’s alignment.
During the last peak, solar fields hitting the Earth were first anti-aligned then aligned. Anti-aligned fields can energize particles, but in this case, the energy came before the particles themselves, which doesn’t create much of a fuss in terms of geomagnetic storms and disruptions.
But the next cycle will see aligned, then anti-aligned fields, in theory amplifying the effects of the storms as they hit.
Raeder likens the difference to igniting a gas stove one of two ways: In the first way, the gas is turned on and the stove is lit and you get a flame. In the other way, you let the gas run for awhile, so that when you add the gas you get a much bigger boom.
“It should be that we’re in for a tough time in the next 11 years,” Sibeck said.
The years ahead could be especially lively. Raeder explains: “We’re entering Solar Cycle 24. For reasons not fully understood, CMEs in even-numbered solar cycles (like 24) tend to hit Earth with a leading edge that is magnetized north. Such a CME should open a breach and load the magnetosphere with plasma just before the storm gets underway. It’s the perfect sequence for a really big event.”
Sibeck agrees. “This could result in stronger geomagnetic storms than we have seen in many years.”