DANCING ATOMS: AURORA BOREALIS

If you live in the northern hemisphere, you stand a very good chance of seeing the aurora borealis this evening. We got a spectacular showing last night. Those glorious dancing lights will be most visible from 11PM-4AM PST with their brilliance tapering off over the next few days.

Even with a fair bit of light pollution, you can see the colours quite clearly. Tonight's best showing is in the late afternoon to early evening. I am excited to see what we will see. 

The Earth has a magnetic field with north and south poles. The lights we see are the result of severe storms that push protons past their normal threshold around these two polar regions.  

The magnetic field of the Earth is surrounded by the magnetosphere which keeps most of the particles from the Sun from hitting the Earth. Some of these particles from the solar wind enter the atmosphere at one million miles per hour. The auroras occur when highly charged electrons from the solar wind interact with elements in the Earth's atmosphere and become trapped in the Earth's magnetic field. 

We see them as an undulating visual field of red, yellow, green, blue and purple dancing high in the Earth's atmosphere — about 100 to 400 kilometres above us. The green is the result of millions of oxygen atoms dancing like gleeful children as they decay back to their original state. 

The red is also caused by oxygen atoms but because those atoms are higher up in the atmosphere we register much of their vivid colour as green or reddish-green because of our poorly developed eyesight and lower red light emissions. 

Nitrogen atoms are a bit more standoffish. They get in on the action but only if the storm winds are very strong as it takes quite a hard hit to excite them. 

If you have been in the quiet northern regions for an aurora storm, you can hear their clapping sounds. On cold, clear nights, with light wind, a temperature inversion can form. This happens when a layer of relatively warm air creates a blanket over a shallow layer of cold air. 

Solar winds excite the atoms in the inversion layer, with opposite charges building up in the colder layer near the ground. When the aurora increases in intensity, geomagnetic disturbances travel down through the atmosphere causing the two layers to spark. 

We hear that electric discharge or spark as a click, click, click, clapping or banging sound. 

All science aside, what we see from these rare energetic interactions is one of the most beautiful of all-natural phenomena — Earth's polar lights, the aurora borealis in the north and the aurora australis, near the south pole. Vancouver had a wonderful surprise viewing a few weeks ago and tonight looks like it will provide another. 

The aurora borealis is best viewed in the north, of course, and many of my relatives have a bird's-eye view. To the Tlingit First Nation of Alaska, the aurora is Gis'óok. In Norway, the aurora is Nordlys — and by any name, spectacular. 

AURORA CAM

Explore.org have a live Aurora Cam and a ton of others that are equally interesting. To view, visit their site at: https://explore.org/livecams/zen-den/northern-lights-cam / Aurora Watch: https://auroraforecast.com/

Interested to learn more about the Sound of the Aurora? Give Meteorologist Michael Karow's thoughts a gander: https://weatherology.com/trending/articles/Sound-Aurora.html