If you live at a northern latitude, there’s a chance you’ve been lucky enough to see the Northern Lights, which is also known as aurora. Even if you live in a northern latitude, several factors have to come together for northern light viewing. First of all, what are they? Well, let’s start with our sun. The sun is an interesting ball of hot gaseous material that can often act up and burp charged particles into outer space. If this violent storm is pointed in our direction, these charged particles will ride the solar wind at speeds of more than 7 million miles per hour. When they reach Earth, they interact with the magnetic field and are drawn to both the north and south poles where the magnetic field is weaker allowing those particles to interact with our atmosphere.
There are several websites that offer northern lights alerting options, but a good start is from NOAA’s Space Weather Prediction Center. This site keeps an eye on space weather conditions and any other interesting stories that are happening in the space realm. Here you can find information regarding “Solar Flares” or “Coronal Mass Ejections”, which are basically storms on the sun. When one of these storms on the sun is Earth directed, NOAA’s Space Weather Prediction Center will have information on it. They also running a model called the OVATION-Prime Model, which shows a fairly short-term forecast if and when the the aurora are possible.
Another thing to keep an eye on is the Planetary K-Index, which helps to describe how active the aurora is and how far south the aurora could potentially be viewed (weather-permitting). The images below show an example of a very intense solar storm that impacted Earth on March 18th, 2015 and sent Planetary K-Index values up to 8, which is pretty extreme! Note that a Planetary K-Index of 5 or higher can generally be seen along the northern tier of the nation (weather-permitting). A Planetary K-Index of 9 could potentially be seen as far south as the middle part of the country!
Optimum Viewing and What Are the Colors?
One of the biggest concerns with viewing the aurora is weather. Skies generally have to be clear for the best viewing options, so keep an eye on forecasts and if you know that northern lights will be possible, it might be worth it to drive to a location that might have better sky conditions. Also, getting away from the ambient light of major cities and nights where the moon isn’t so bright can also increase your chances of seeing them. If you get into a desired spot and can see the lights, several different colors may be seen. Depending on the specific particle and altitude that this particle is being excited at, nitrogen and oxygen molecules will turn different colors. The image below from AuroraSaurus helps to describe when they turn different colors.
With that… happy viewing! I hope this helps increase your odds of viewing the aurora at some point in your life. If you haven’t seen them, they really are something to behold and worth the effort in trying to see them. Good luck! I will leave you with an incredible picture taken from the International Space Station above the aurora… Pretty neat!
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