Friday, March 24, 2017

Aurora Borealis & Solar Rotation

I have seen the claim that aurorae here are on Earth are often synchronized with sunspot activity on the Sun.  Because the Sun does one rotation every 28 days or so, the previous 28 day aurorae are a pretty good predictor today.  Looking through this archive of aurorae data suggests that this is true.  This matters because aurorae are on our bucket list.  There are pretty good aurorae predicted for the 28th.  If money were no object, we would catch a plane for Fairbanks in a couple of days.  But leaving March 25 for a week is $930 per person. If the 28 day rotation cycle is correct, April 24-27 should also be good, and far enough out for $437 per person.  Even then there should be plenty of hours of dark sky.

It looks like there is still some snow risk in late April, so a 4x4 rental might be a good idea.  I know there are Alaskans reading this blog; enlighten me.

Peak forecast now March 28 -29.


  1. Hi Clayton, I lived in Alaska 25 yrs, including 3 in Squarebanks. This site shows sunrise/sunset times

    Best times for the aurora are gingsenerally 2 am to 5 am. Chena Hot Springs is about 60 mi. east of Fairbanks, there is a lodge with an indoor/outdoor pool. It is a blast to be watching the aurora at 50 below in a hot pool.

    I hope you guys can make it up there. Fairbanks has a strong gun rights commnity, you might contact locals to see about giving a talk there.

  2. It is hardly a claim - it's a fact. Aurora effects are related to geomagnetic disturbances, and those are driven by the sun.

    And, it isn't just the aurora. Radio signal propagation is greatly affected. Amateur radio operators know that they can use less power on higher frequencies to talk long distance when there are a lot of sunspots.

  3. John: In your experience, is late April likely to give us auroras?

  4. Clayton,
    I'm no expert on aurora (unlike my late father, a professor who researched the ionosphere as part of his doctorate). But I found a reference that says: yes in terms of aurora frequency.

    On cloud cover... This is just a rough guess... this time of year the weather tends to change frequently in the continental US, as the jet stream wave pattern is active and at our latitudes. So my guess for your area would be a substantial variation in cloud cover from day to day.

    The reference: