The skies treated us with an asteroid for Halloween, a full moon for Christmas and some parts of the world might get to see the aurora borealis on New Year's Eve. Solar flares and the resulting geomagnetic storms on Earth may cause the northern lights to dazzle for some skywatchers as 2015 comes to a close.
This instance of the northern lights may be seen in Oregon or possibly as far south as the San Francisco Bay Area. The Australian Bureau of Meteorology reports that the phenomenon may be witnessed Down Under as well.
The phenomenon here on Earth is caused by weather on the sun. Lucky residents in these areas have activity some 92 million miles from Earth to thank. According to EarthSky, "When the charged particles from the sun strike atoms and molecules in Earth’s atmosphere, they excite those atoms, causing them to light up."
The stage was set for this particular showing of the aurora borealis earlier this week. On Dec. 28, NASA’s Solar Dynamics Observatory detected a M1.9-class solar flare. The flare created a coronal mass ejection, which shot out in the direction of Earth. According to SpaceWeatherLive.com, a coronal mass ejection, or CME is, "a giant cloud of solar plasma drenched with magnetic field lines that are blown away from the sun during strong, long-duration solar flares and filament eruptions." When the CME approaches Earth, it can cause geomagnetic storms above our planet. The resulting northern lights might be seen as early as Dec. 30. They could continue into the New Year’s Eve holiday if the storms are strong enough.
Geomagnetic storms are a fascinating and complicated phenomena that can affect the Earth in many ways, ranging from causing changes to Earth’s magnetosphere to heating up the Earth’s ionosphere. A geomagnetic storm is defined by NOAA as, “a major disturbance of Earth's magnetosphere that occurs when there is a very efficient exchange of energy from the solar wind into the space environment surrounding Earth.” For a geomagnetic storm to occur, NOAA explains, other factors such as the direction of the solar winds must be just right.
While a geomagnetic storm might sound dangerous, authorities note not to worry about this one, which is rated as a G3-class geomagnetic storm on a scale of G1 to G5, with G5 being the most intense. CNET explains, “These storms don't pose any threat, but they can sometimes disrupt communications technology, particularly those that use high frequencies like HAM radios.” In some instances, geomagnetic storms have knocked power grids offline, but the New Year’s Eve geomagnetic storm should only result in a light show for lucky skywatchers.
So, if you live in the northern latitudes, look upward as you ring in the New Year while the aurora provides the fireworks.