WOW! Aurora sparks excitement across the country

"With my friend Tony we drove into the country hoping to find some aurora away from city lights. What we found blew us away, it was a once in a lifetime experience, and was by far my best aurora experience ever." Photo by Malcolm Park of Whitby, Ontario, Canada

First off, I want to thank everyone who sent along a comment or observation of the aurora last night. It was thrilling to read how spectacular the display was and how far and wide it was seen. People wrote from Arkansas, Kansas, Maryland, Ontario and Tennessee and even Minnesota, where most of the state was under a heavy blanket of clouds. I stepped outside and checked the sky often during the night, but the clouds never budged. Just the same, your excitement was so palpable, it almost felt like being there.

According to the folks at the National Oceanic and Atmospheric Agency or NOAA, the geomagnetic storm that gave rise to the northern lights was a class G2 or moderate storm. Disturbances to Earth’s magnetic field caused by the sun are rated from G1 – minor with aurora visible in along the borders of northern U.S. states – to G5, which can seriously affect power grids, cause damage to satellite components, blank out radio communications and send auroras all the way down to Florida and southern Texas.

Red, the most exciting color in auroras and not often seen, was widespread in last night's display. This photo was taken by Shawn Malone of Marquette, Michigan. His reaction to the display was similar to what many people felt who saw it -- "WOWOWOWOW! Incredible!"

In last night’s storm, a stream of plasma shot connected to a solar flare or other activity on the sun belted a cloud of high-speed electrons and protons in the Earth’s direction. The average speed of one of these clouds or sprays is over 300 miles per second. When it reached the Earth’s vicinity yesterday afternoon, it strongly compressed the big magnetic bubble around the planet called the magnetosphere, squeezing billions of electrons straight into our atmosphere¬† some 60 to 200 miles overhead.

Fisheye-lens view of the incredible red auroral rays taken by John Chumack in Yellow Springs, Ohio.

When the electrons strike the oxygen and nitrogen atoms at that altitude, they excite them into a higher energy state. As the atoms return to their normal “ground” state, they emit light of different colors. The most commonly seen hue is green from excited oxygen. Because many auroras are faint, this color frequently appears pale white to the eye, but a time exposure with a camera will clearly reveal their green color. Red also stems from oxygen but it occurs higher up, which is why green rays are often topped by red. The strongest color emissions from nitrogen are in the deep violet end of the rainbow spectrum and invisible to the human eye. Another nitrogen excited state creates the red lower border to the aurora.

Artist rendition of Earth's protective magnetic bubble called the magnetosphere. As material from the sun streams toward the Earth, much is deflected away, but sometimes we take a hit. Subatomic particles like electrons and protons find their way in, where the magnetic field lines guide them into the upper atmosphere to spark auroras. Credit: NASA

Once inside the bubble and on their way down, electrons follow the invisible lines of magnetic force in Earth’s magnetic field. They’re the same ones you see when you sprinkle iron filings around an ordinary magnet. Electrons spiraling around the many approximately parallel field lines in the polar regions create the multiple parallel rays that are so characteristic of the northern lights.

Another colorful view of last night's northern lights from Shawn Malone of Marquette, Michigan

After a big auroral display, there will often be some “leftovers” the next night or two. I checked the NOAA space weather forecast this morning to see what might be in store. Although solar activity is presently low, lingering effects of the sun’s coronal mass ejection should continue through today and possibly into tonight. Keep an eye on the forecast and the Kp index, which is a gauge of changes in Earth’s magnetic field as measured by surface instruments. Make note of the rightmost bar in the graph at the Planetary Kp-index Monitor. This is the most recent plot of activity. If it’s green, meaning the index is below 4, no storm is in progress. A yellow bar at K = 4 indicates activity is picking up and a red bar (K = greater than 4) signals that’s it’s time to put on your coat and go out for a look!

7 thoughts on “WOW! Aurora sparks excitement across the country

  1. i was taking out the trash last night and saw the red sky! it really was amazing!Thank god I went outside when i did. i got to experience something i’ll probably never see again. im from Indiana. i didn’t know what it was at first but then read ur blog!

  2. Amazing how much of the country saw this display. I was all set to sit out and photograph but the cloud bank over northern MN just didn’t move. Unfortunately, looks like northern MN is going to be stuck with clouds again tonight. Since the sun seems to be pretty active lately hopefully we’ll get another chance soon.

  3. I observed this amazing site around 2130 e s t in Brooklin, Ontario. Was amazed and quite humbled by the forces at work in our galaxy and the universe!

  4. Too bad the clouds robbed us of that spectacular display. Last evening while driving home from Duluth, I saw a hint of the Aurora to the northeast around 7pm but only for a few minutes. Thanks for sharing all the photos from everyone who sent them in.

  5. I live in Alaska, so have seen the aurora plenty of times…though I missed the recent show!
    Red auroras are indeed rare, and I’ve seen them only once. When that occurred, I lived in an Eskimo village on the Yukon delta, about 20 miles from the Bering Sea coast. The night after the red aurora, there was quite a stir in the entire village, as the elders were quite upset. Why? Red auroras signaled impending war. When did this happen? September, 2011.

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