Iowans have been treated to numerous rounds of the northern lights in recent months.A few of these displays have been quite vivid, leading some to ask why space weather has been so active lately.The cause comes from patterns in solar activity.Solar cycles and the northern lightsOur sun's magnetic field goes through a cycle every 11 years. These magnetic fluctuations change the number of sunspots that appear on the sun's surface.More sunspots appear during the active part of that cycle, and solar activity increases. The sun more frequently unleashes explosions of energy like solar flares and "coronal mass ejections."Solar flares are essentially violent releases of radiation. They spread out in all directions at the speed of light and can reach Earth in mere minutes.Coronal mass ejections are giant blobs of plasma (magnetically charged particles) that erupt out of the sun. They travel in just one direction -- sometimes toward Earth, sometimes not. CMEs are also slower. One of them might take 2-3 days to reach us. Coronal mass ejections hitting Earth are a common cause of the northern lights. Current solar cycleThe northern lights have been appearing more frequently because we are currently at the most active part of the current solar cycle -- called a solar maximum. Our current 11-year cycle is projected to peak sometime from now into early 2025.As we continue through this solar maximum, more sunspots are appearing, and space weather has gotten more active. The chart below from NOAA's Space Weather Prediction Center shows that our last solar maximum occurred in 2014. The cycle before that peaked in the early 2000s. Appearances from the northern lights will likely keep coming into next year.That means more beautiful celestial displays but also more communications disruptions. Increased solar activity often interferes with technology like telecom networks and GPS. For example, some farmers with implements reliant on GPS were affected earlier this spring.More impacts on this sort of equipment are likely into 2025.

Iowans have been treated to numerous rounds of the northern lights in recent months.

A few of these displays have been quite vivid, leading some to ask why space weather has been so active lately.

Our sun's magnetic field goes through a cycle every 11 years.

These magnetic fluctuations change the number of sunspots that appear on the sun's surface.

More sunspots appear during the active part of that cycle, and solar activity increases. The sun more frequently unleashes explosions of energy like solar flares and "coronal mass ejections."

Solar flares are essentially violent releases of radiation. They spread out in all directions at the speed of light and can reach Earth in mere minutes.

Coronal mass ejections are giant blobs of plasma (magnetically charged particles) that erupt out of the sun. They travel in just one direction -- sometimes toward Earth, sometimes not. CMEs are also slower. One of them might take 2-3 days to reach us.

Coronal mass ejections hitting Earth are a common cause of the northern lights.

Current solar cycle

The northern lights have been appearing more frequently because we are currently at the most active part of the current solar cycle -- called a solar maximum.

Our current 11-year cycle is projected to peak sometime from now into early 2025.

As we continue through this solar maximum, more sunspots are appearing, and space weather has gotten more active.

The chart below from NOAA's Space Weather Prediction Center shows that our last solar maximum occurred in 2014. The cycle before that peaked in the early 2000s.

Appearances from the northern lights will likely keep coming into next year.

That means more beautiful celestial displays but also more communications disruptions.

Increased solar activity often interferes with technology like telecom networks and GPS. For example, some farmers with implements reliant on GPS were affected earlier this spring.

More impacts on this sort of equipment are likely into 2025.