Photos: Northern lights over upper U.S. may continue this week

WEATHER NEWS: Photos: Northern lights over upper U.S. may continue this week

While clouds obscured many potential viewing areas, aurora reports came in from across the northern United States, including Washington state, Wyoming, Montana and South Dakota.

Photographer Kevin Palmer captured the light show around 10 p.m. at Tongue River Reservoir in Decker, Mont. “In a decade of aurora watching, these were some of the best reds I’ve ever seen. Normally red is only visible to the camera, but these colors were easily seen with the naked eye,” Palmer wrote on the website.

To escape the clouds, photographer Marybeth Kiczenski drove more than 20 hours in snowy and icy weather and finally landed at a beautiful scene at the Devils Tower National Monument near Sundance, Wyo.

Auroras are created when a surge of charged particles from the sun interact with Earth’s magnetic field. In this case, the surge of charged particles came from coronal mass ejections (CMEs), or explosions of plasma and magnetism from the sun, on Monday. Instruments detected the CME arrival at Earth around 10:10 p.m. Eastern on Wednesday.

As the solar particles come close to Earth, some get trapped along our planet’s magnetic field lines and flow into our upper atmosphere, where they impart energy and excite atoms and molecules of gases such as nitrogen and oxygen. As the molecules calm down and return to their normal state, they release photons of light. During large enough solar storms, billions of these collisions can occur, releasing enough light for us to see with our naked eyes — resulting in the northern lights.

The colors of the aurora correspond to the type and altitude of molecule that is excited. Excited oxygen can glow both green and red. Green typically occurs between 75 and 110 miles, while red occurs above 120 miles.

Excited nitrogen molecules at altitudes between 75 and 110 miles can produce a blue light. Below 60 miles, nitrogen can give off both blue and red light, which can often appear purple to pink.

More geomagnetic activity and auroras could occur later in the following days. On Wednesday, another coronal mass ejection erupted, which forecasters are analyzing. The ejection was associated with an X-class solar flare (the most intense solar flare class), which may have disrupted radio communications over North and South America. According to Space Weather Watch, Earth could experience more geomagnetic activity from this event by the end of the week, affecting the United States from Thursday night into Friday morning.

The bout of geomagnetic activity is a small taste of what is to come in upcoming years, as the sun enters a more active period of its solar cycle, which is expected to peak around 2025.

But until the next aurora, we can enjoy these views from Wednesday night into Thursday:

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