Aurora

 

My first experiences with Aurora surprisingly occurred in Orlando, Florida on March 13, 1989. On that evening, I had to take out the garbage for the next day and suddenly noticed the sky was an odd red color. As I pondered the color of the sky, I assumed a fire must be nearby but heard no fire engines/alarms. A glance towards the first quarter moon revealed a red glow around it and suddenly, I realized that the recent solar flare event had triggered a massive aurora visible at my latitude. The actual event was seen in the Bahamas! I scrambled into the house and grabbed all my extra film and photographed the event. As I took photographs, I was calling fellow astronomers and friends to alert them of what was happening. It was a thrilling event and I wanted to see more. Fortunately, the Navy allowed me the chance to do exactly that.

In May 1989, the US Navy transferred me to Groton, Connecticut for a tour of duty aboard the submarine USS Providence. While I was there, I saw many auroras since it was around the solar maximum. 1991 was a particularly good year and I became adept at figuring out the WWV broadcasts foretelling a good geomagnetic storm. One of the more impressive observations came when I was flying back from Chicago(I had just seen the Baja solar eclipse). During the flight I had a window seat on the port side of the plane and looked out my window after it got dark. To the north, I could see the auroral oval stretching across the summer sky. It was quite impressive and words can't seem to capture the event. By 1994, I had seen quite a few but was again transferred to Orlando (at my request), thus preventing me from seeing any more.

It wasn't until returning to the great white north that I began to see Aurora again. In 2000, I retired to New Hampshire, where I began to chase the aurora again. Unfortunately, weather or the moon always seemed to interfere and I did not photograph or see many Aurora until 2002. To date, I have seen and photographed quite a few aurora and hope to continue to do so for some time. At least, that is until I return to the warmer climate of Florida.

What causes Aurora?

Basically, it is the sun's activity. As the particles from the sun bombard the earth's atmosphere, the individual molecules in the earth's atmosphere become "excited". These molecules of Nitrogen and Oxygen want to revert back to their original stable state. In order to do so they have to release this energy, which they do in the form of light waves. The type/color of light is dependent on the excitation levels these molecules reach. The common green colors are due to Nitrogen and Oxygen. However, if the Oxygen is raised to a higher energy level, it will emit red light. All this occurs at altitudes of 90-400 Km above the earth's surface and centered around the earth's magnetic poles. These magnetic poles are not at the north or south geographic poles. The north magnetic pole is north of Canada but not at 90 degrees latitude. For starters, you can read more detailed information about the subject at http://www.oulu.fi/~spaceweb/textbook/auroras.html.

When can I see an Aurora?

Tough question and there are many on-line indicators to help understand if the aurora will be visible. The best indicator for aurora potential can be found at http://www.aurorasentry.net/. Information to help understand and interpret some of the indicators on this web page can be found http://www.sec.noaa.gov/Aurora/index.html. Subscribing to an alert list may help as well. Once it looks like an aurora may occur, feel free to go outside away bright lights and look north. If you are at mid-northern latitudes and there is a major storm in progress, your chances may be good that you will see one

Photographs

Taking pictures is lots of fun. Just bring ISO 400 film, use a 50mm or 28mm lens with the f-stop wide open and expose the image between 10-60 seconds. With luck you may get photographs similar to the ones I have posted on the following web pages, which document some of my more spectacular aurora events:

March 13, 1989 - The sky was on fire! Orlando, Florida

June 1991 - Activity before the big solar eclipse. Connecticut

November 1991 - Aurora photographed near a graveyard. Ledyard, Connecticut

April 2002 - Aurora from my backyard. Manchester, NH

September 7, 2002 - Aurora from Lake Massabesic, NH

September 8, 2002 - Aurora fires back up. Manchester, NH

October 30, 2003 - The weather clears in time!

November 8, 2004 - An aurora movie

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