Over the past year, members of our communities, people across the state, and even people living across the nation, as well as other continents, have had more opportunities than typical to view the Aurora Borealis, otherwise known as the Northern Lights.
The views can be visible through a camera lens, and in some instances are visible to the naked eye. Thanks to social media, people have been able to alert each other when the lights are visible and where to go to get a chance to see them.
Sightings of the Aurora Borealis aren’t unheard of in Minnesota, but lately, it seems like residents of our state and area have been treated to viewings more frequently than ever before. Not only are Minnesotans getting front-row seats to the lights, but viewers as far south as Missouri have been lucky enough to experience them.
The southern hemisphere has an aurora, too, known as aurora polaris. Auroras occur when charged particles (electrons and protons) collide with gases in Earth’s upper atmosphere. The collisions produce tiny flashes that fill the sky with colorful light. As billions of flashes occur in sequence, the auroras appear to move in the sky. Our planet’s magnetic field forms an invisible shield that protects us from the solar wind. Occasionally, the solar wind penetrates Earth’s magnetic field and the stream of particles interacts with gases in the magnetic field, generating magnificent auroras. Generally, the more active the sun is, the more active the auroras will appear on Earth.
Our sun has what is called a solar cycle. It is an 11-year periodic change in the sun’s activity, measured by the variations in the number of observed sunspots on the surface of the sun. Over this period, levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit fluctuations from minimum to maximum activity, and back again to minimum. During each solar cycle, the magnetic field of the sun flips which happens while the cycle is near its maximum.
Right now, we are heading towards a solar maximum, which is expected to occur in July of 2025. As we head towards the solar maximum, the solar events that cause auroras will become more common, according to Robert Massey, executive director at the Royal Astronomical Society.
Scientists such as Mark Miesch, a research scientist at the University of Colorado, predict that the Northern Lights will continue to be active until the fall of 2024 if the sunspot observations continue to increase. They will be the most viewable, and from more places on Earth, than they have been in the past 20 years, and likely will be in the next decade.
Recently, locals were treated to a show of not only the Northern Lights but also a geminid meteor shower simultaneously.
Many smartphone applications can notify you when the Northern Lights are visible, and joining local Facebook groups can help you stay in the loop, as well. The lights are best viewed away from other light pollution and on a clear night with little to no clouds.
Local photographer Kaedan Fischer says he uses forecasting tools, such as the National Oceanic and Atmospheric Administration (NOAA) website, Space Weather Live which has both a website and a smartphone application to see the Interplanetary Field (IMF) and Bz levels (a measure of the North/South orientation of the interplanetary magnetic field measured perpendicular to the ecliptic plane.) “On top of that, I use radar, generally from RadarScope, or COD NexLab Numerical Forecast tools,” he says, “With forecast tools, I am generally looking for cloud cover, whether that be OVC (Overcast), SCT (Scattered), or CLR (clear.)” The cloud cover forecasts let him know where there will be open skies, and when. “To easily explain forecasting a good night for the aurora, you want clear skies, a high IMF (10+ is good), and a low Bz level,” he adds, “A rule of thumb to remember when comparing IMF and Bz levels is when Bz levels are negative, your viewing chances will be positive. What that means is if I have an IMF of 10, and a Bz of -10 along with clear skies, the aurora will be very good.”
Fischer also has experience with storm chasing locally and uses COD to forecast the hot spots in a storm.