A FEW WORDS ABOUT THE AURORA BOREALIS
If you think it’s difficult predicting the weather a few days in advance, consider attempting to forecast the appearance of the northern lights as far ahead as October 2016! That’s a tough assignment, and it’s impossible to be completely accurate, but we can make some generalized comments about what you can expect to see.
Currently the Sun remains active, even though the solar cycle is no longer at maximum. For reasons not yet understood, the Sun is more active after solar maximum than before. Consequently, it’s still possible we’ll experience a Coronal Mass Ejection (CME), a major solar outburst that often results in spectacular displays of the northern lights.
In addition, we’ll see auroral activity thanks to coronal holes – openings in the Sun’s magnetic field that let its powerful solar wind escape into space. When one of these holes is pointed toward Earth, the result is a lovely show of the northern lights at high-latitude locations such as Iceland.
Unfortunately, astronomers can’t predict the eruption of a CME or the emergence of coronal holes. But when one or the other is observed, they can estimate when the charged solar particles will strike Earth’s atmosphere and cause the aurora to dance. So as well as checking the sky each night, we’ll be monitoring solar activity websites every day.
One more thing. For reasons unknown to astronomers, aurora activity peaks following the spring and autumn equinoxes. This is why we plan to be in the dark skies of the Icelandic countryside shortly after the autumn equinox.
