Space Weather: March is Aurora Season, Particularly This Year

We should not forget that the Earth's atmosphere can be seriously influenced by the "weather" on the sun!

Auuoral displays are particularly frequent in March for reasons I will explain later.

The sun's surface is not uniform over time, with varying sunspots and "solar storms", including solar flares and coronal mass ejections (CME), that send solar particles away from the sun and can greatly disturb the sun's magnetic fields.  

Such solar disturbances can be associated with higher-latitude auroras and the disruption of  radio communication and electricity transmission.

CMEs and other solar disturbances are modulated by the number of sunspots on the sun's surface, with more sunspots resulting in more activity.

Sunspots vary over time, with an eleven-year cycle being the most prominent (see below)

Importantly, we are now approaching the peak of a cycle (see a blow-up image below).  So there is an increased probability of solar "action" during this period.

But there is more.    

The potential for auroras and other solar impacts on Earth is maximized in our current season.  As shown in the next figure, the number of days in which solar disturbances impact the earth; 's atmosphere peaks in early spring and early fall, near the time of the equinoxes (night and day being similar lengths)

Why is that?     

It has to do with the orientation of the earth's axis relative to the sun.   During the equinox, the poles are oriented perpendicular to the sun's rays and the magnetic fields of the sun and earth are aligned in an optimal way to produce auroras (I will not go into the details here).

As an aside, you can see the nearly simultaneous sunrise north to south from the visible satellite image this morning (below).   The terminator separating day from night is a vertical line from the north to south poles.

So should you expect any auroral activity soon?   The NOAA Space Weather Center has declared a MINOR geomagnetic storm alert after some minor solar flares a few days ago.  Nothing serious, but it should rev up auoral activity in northern latitudes.   Nothing serious.

But be ready for more interesting solar storms.    The geophysical dice are weighted in their favor this year and season.