A couple days ago, a relatively weak M-class solar flare on the sun produced a coronal mass ejection.  This CME was directed at Earth, with a South-pointing polarity. In other words, it was good for producing Northern Lights!  Actually the flare was small enough, and the CME slow enough that I wasn't expecting anything substantial as far as Aurora on this day...or at least anything I'd be able to see.  As I was getting my backyard observatory open just after dusk and getting ready to take some photos, I realized there was something wrong with the sky to the north. It was supposed to be a nearly 100% clear day. I was disappointed that there was a bank of clouds that appeared to be rolling in from the north.  The clouds were odd however, So i watched them for a moment. They were green, and diffuse. Strange for clouds of course, but a bit strange for Aurora too. 
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observatory with faint northern lights
Having my camera handy, I took a picture of them just to see what would show up on the sensor. Eyes aren't terribly sensitive to narrow-band light like Aurora, so they often appear dim and almost colorless in some cases.  The camera confirmed it. These are the Northern Lights!  I proceeded to take a few beauty shots of the observatory, and then finally set up for a timelapse. That would end up being a very important decision!

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Strong GeoStorm
I let the timelapse run for about 2 hours.  The first hour or so showed a weak green glow and little else.  But near the end, an explosion of color occurred. I was lucky enough to be standing outside right at the onset of the major storm.  After this brief display ended, I shut down the timelapse to have a look. Wow was that cool on camera!  That night I stitched it together into a video and uploaded it to youtube, then posted about it on my facebook and a couple blogs.

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Within a couple days, the video had been viewed 350,000 times. It had been spotted on CNN, MSNBC, Foxnews, and dozens of local stations across the country.  Perhaps 10's of Millions of people have seen this video! Have you?  Youtube itself posted the video to its facebook page! Resulting in a melee of hits and comments.

 
 
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Northern Lights - Southern Michigan - Nov 2001
Kp Index of 8
I'd like to take on the misconception that Northern Lights are either rare, or Impossible to see from the state of Michigan.  Since the new Solar Maximum is approaching, (2012-2013) this is a good time to spread some advice on when and how to view the Northern Lights from our extremely lucky location in the world.  And also issue a warning that our luck is about to run out.

The Great Lakes are quite special in recent history in that we are probably the warmest location on earth from which to see Northern Lights on a pretty regular basis. Southern New Zealand and Tasmania would be our nearest competition and even they get to see them a lot less often than the upper Great Lakes do.  'Regular' not 'Rare.' depending on how you look at it.  There are several reasons for this.  Our Latitude on the planet is roughly on either side of the 45 degree parallel, the half-way point between the equator and the North Pole.  However,  Auroras don't really cling or depend on the earth's polar axis, or the axis of rotation of the earth.  Alaska for example is well known for its northern lights "Because it's so close to the north pole"

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Northern Lights at Zenith (Directly overhead)
Southern Michigan - Nov 2003
Kp Index of 9+
That's actually not the reason. The reason Alaska is known for its Aurora is because some areas of it lie directly underneath the 'Auroral Oval' or a ring of nearly continuous Northern Lights that is centered around the MAGNETIC North Pole.  This spot on earth, as of ~2005 was located at 82 degrees North, and 114 Degrees West longitude.  Michigan is at about 83 degrees west. This means that the Magnetic North Pole is actually about 8 degrees, or a few hundred miles closer to us than the North Pole. officially, our "Geomagnetic" Latitude here in Michigan is between 52 degrees North at the southern end and about 56 degrees north Geomagnetic Latitude, closer to Lake Superior.  The standard aurora oval "lives" at about 62 degrees north Geomagnetic Latitude.  In other words, if you live in Marquette, MI for example, you live less than 6 degrees away from where the aurora 'lives.'   If you imagine an Arc that goes from central Alaska down through Edmonton, Canada, and finally between Lake Superior and the Hudson Bay, this is the normal auroral oval for Midnight local time.  To see the Aurora, you need to be standing at or less than 6 degrees away from where they are positioned over the Earth. So in theory, a place like Marquette should be able to see them virtually every day. Really? I'll explain...

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Northern Lights ('SubStorm') - Southern Michigan - Dec 2003
Kp Index of 6
Now Alaska as mentioned sits under the Auroral Oval, but it's not that simple. Northern Lights come in and out of higher periods of activity depending on the speed, polarity, density and temperature of solar wind particles hitting Earth's magnetic field. Ok yes, that's a lot of words, let me fix that.  What I mean is that when the sun gets more active, Northern lights get more interesting.  When they get more interesting they become brighter, and taller. They also move more, and take on spectacular shapes and colors.  The aurora oval itself begins to expand and when it does, it pushes northern lights further south.  If the Aurora is quiet, Not even that many Alaskans will see Northern Lights.  If they can see it during quiet periods, the northern lights will often be slow, dim, and colorless to the eyes.

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Northern Lights - Southern Michigan - Oct 2006
Kp Index of 5
How often do they 'get more interesting'?  Auroral activity is measured by a simple value called the global Kuiper index or Kp.  A wing of NOAA (the U.S. National Oceanic and Atmospheric Administration) called the Space Weather Prediction Center or SWPC measures this activity and assigns it a value from 0 to 9. A quiet Aurora has a value of 1, 2, or 3.  While 0 means there's nothing visible at all.  It is reliably at least a 1 or 2 during 'Solar Minimum' and reliably at least 2 or 3 during 'Solar Maximum.'  However certain events on the sun frequently send this index higher especially during Solar Maximum. 

The Solar Maximum and Minimum are the ups and downs of activity on the sun, specifically the amount of Sunspots on the sun are  more numerous during Solar Max. This  cycle of activity on the sun occurs over a period of about 11 years.  The last Solar Max occurred between 2000 and 2003. The next Solar Max will occur between 2011 and 2014.  Major solar flares and solar wind gusts will increase the intensity of the Aurora.

Just a 2-fold increase in the speed of the solar wind will up the Kp index often to a 4 or even a 5. While solar storms (Called CMEs or Coronal Mass Ejections) can occur during solar maximum and push the value as high as 9, though 6 or 7 is more typical during a "Geomagnetic Storm."   This is the name given to a heightened period of Northern Lights and other phenomenon. Fits of faster solar wind causing levels of 4 and 5 happen even during solar minimum and as often as once every other week on average.  While solar storms causing Kp values of 6, 7 and higher typically only happen close to solar maximum and can happen as often as several times in one month or just once during an entire year.

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Northern Lights - Nov 2003 - Southern Michigan,
under bright city lights - Kp Index of 7
What does that mean for Michigan? Well if you live in Marquette, or especially Copper Harbor, this means you should be able to see northern lights when the Kp value is a 3 or higher. As  I mentioned earlier that happens RELIABLY. or all the time.  Because these towns are close to Lake superior, getting a clear unobstructed view of the Northern sky is critical and easy to find. Unfortunately you also have to have a nearly clear night and it needs to be clear around Midnight.  That can be tricky on Lake Superior during certain months of the year. The hours before and after midnight is when the Auroral Oval is generally closest to your location, wherever you are on Earth.  Now keep in mind that daylight savings time pushes that to 1 am, and since Michigan lies on the far western edge of our timezone, add another half-hour to that.

Michigan's local midnight is about 1:30 AM during daylight savings time, and 12:30 AM otherwise.  So if you live in the U.P, find out when the Kp index is a 3 or better on a clear night, at around 1:30 AM and find yourself a clear view of the Northern sky. Your chances will be quite high that you'll see northern lights. I'll explain how to do that in just a bit.

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Northern Lights - Southern Michigan - Dec 2006 - Kp Index of 6-7
Now areas such as Ludington, Frankfurt, Mackinaw, and Alpena typically need to wait for a Kp index of about 4 during local midnight. Again this happens at least once every other week, however you also have to contend with this happening AT midnight, and when there are few clouds in the sky, you'll also need a view of the northern Horizon..no Trees and no city lights or hills in the way. That's a little tougher than it is for Copper Harbor residents, but not impossible. 

 - Map of the Average southern extent of the Auroral Oval as a function of Kp Index value -

For Grand Rapids, Saginaw and points south, You need to wait for a Kp index of at least 5. During solar minimum, this doesn't happen very often. Then if you factor in that you need no clouds, a clear view to the north, away from city lights (more of a problem in the southern part of the state) and you need that index of 5 to occur around midnight.  Again not impossible, but not easy to do. You'll likely have to  drive somewhere to see them.  During Solar Maximum, however, A KP index of 5 or better is a pretty regular occurrence. And this is why, in my estimation, Auroras aren't rare here.  Michigan has had 2 F5 Tornadoes in the last 60 years. But there have been hundreds of geomagnetic storms in that time. We haven't had a 100 degree day here since 1988, yet our last geo-storm was in 2006 as of the time I'm writing this.    Here's an example showing 1998, which was about 2-3 years before the last solar maximum, (we are about 2-3 years away from the next one) Showing how many times the Kp index exceeded 5.

As you can see, that year, it happened frequently, about 14 separate times in fact. A number of those times it was greater than 7, which for us means an ideal display.  In 2003, at the end of the height of solar max, there were more than 45 separate events that exceeded 5.  2009, a solar minimum year, it happened just once.  If you are watching from the Upper Peninsula, even in 2009, you could still see northern lights at least once a week on average. During 2003, it would have been virtually every single day.

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2003 August Display in Munising. Kp estimated at 3 to 4
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Northern Lights - Southern Michigan - Nov 2004
Kp index of 8
A Kp index of 5 as viewed from the U.P. is absolutely amazing and awe-inspiring. For an equivalent view in Southern Michigan, we need something around 7 or better.  On two occasions i've witnessed aurora during a Kp 9 storm from a dark location.  You can literally navigate outside solely by the light of the northern lights. White cars turn green, snow turns green. Your skin glows. The northern lights themselves flicker like a candle and sometimes shoot arcs of light across the sky that resemble heat lightning. Truly amazing.  

So what happens in Alaska during the aurora storms?  The same thing, only the areas that 'nearly always' see Northern lights might not see them at all. The Oval pushes further south, out of areas like Fairbanks and into places like Juneau and Anchorage that don't frequently see them.  Much of Alaska cannot see the northern lights about 5 months out of year simply because the sun doesn't go down enough to enjoy them. While in Michigan, we still get 7 hours of darkness in midsummer and it's plenty dark around local midnight.  On the other hand, 5 months of the year in Alaska are completely dark, which means that any auroras, regardless of time of day, might be visible from somewhere in Alaska.

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August 2007 - Munising Display. Kp Index of 4
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January 2003 Auroras
Kp index of 7
How to find them?  Watch for Kp index for a current 'observation' of the strength of the Northern Lights. You can also subscribe to spaceweather.com's spaceweather phone and receive alerts based on any criteria.  To get a forecast of Northern lights, regularly check spaceweather.com  or sec.noaa.gov.   For more advanced users, watch the ACE satellite graphs.  Or even easier than all of those, use my favorite, the Geomagnetic Index forecast.

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Nov 2003 Aurora - Southern Michigan
This upcoming solar Maximum might be your last chance to see them from home.  The Magnetic North pole 'migrates' usually over centuries, from one location to another.  For the last few hundred years it was over north-central Canada in the Northwest Territories.  Today it is wandering, quickly, for reasons scientists are quite certain about, back toward the direction of the North Pole. Theories would show that Europe will soon have a much better position to see Northern Lights. In fact darn good because much of Europe (Scotland, Ireland, Norway and Sweden) is quite close to, or at, the arctic circle already, much further north in Latitude than Michigan is.  As the magnetic pole heads away from us,  our ability to see northern lights diminishes.  30 years ago we only needed a KP index of 4 to see them. Soon it will need to be better than 5. In another 10 years, it may require a 7 or greater.  That means our chances to seen Northern Lights are diminishing, Perhaps someday pictures like mine will only be a memory of how special the Great Lakes were when it comes to Northern Lights.

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August 2003 Munising Display - Kp Index estimated 3-4
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Aurora seen from space on Nov 5-6 2001. Note that the
bright auroras were positioned over Southern Michigan during
a Kp Index of ~8. However they could be SEEN as far south
as Alabama and South Carolina. Any location within 5 or 6
degrees of the position of the aurora can see them near the horizon.
On the other hand, Earth's magnetic field is also weakening. In theory as we get closer to a 'magnetic reversal.'  This takes a long time to happen, but exposes our atmosphere to more and more solar wind. This makes it easier for solar storms to overwhelm Earth's defense and cause stronger episodes of Northern Lights.

So, If you want to see Northern Lights, sit tight and wait for them to come to you, Or take a camping trip to the U.P. during solar max. They aren't that far away from us, you just need to know when and where to look!  Visit spaceweather.com frequently.  Learn about the Earth-Sun system and about the specific events that can cause aurora powerful enough to be seen from virtually anywhere in the Great Lakes or where you live!

Now as you can see, I have a lot of pictures from a variety of intensities, and from a mix of solar minimum and solar maximums.  Every single image was taken in Michigan. And these are just displays that I've actually photographed. There are at least a dozen other times that I've been able to see them, and a couple more times where I could see them, and my photographic equipment either didn't cooperate, or back in the day when film was still king, the processor ruined the images.  If the sky is clear, look up!