‘Solar Maximum’ Is Here: What It Means For Northern Lights In PA

PENNSYLVANIA — The sun is officially at that much-talked-about “solar maximum,” according to NASA, and that means Pennsylvania could see more dazzling northern lights displays over the next year before the sun goes into a more quiet phase.

The addition to enhanced chances to see the aurora borealis in Pennsylvania as the sun reaches the peak of its 11-year cycle, the chances of other communications outages and other difficulties on Earth also go up, NASA and the National Oceanic and Atmospheric Administration said in a teleconference with reporters last week.

Residents across the Keystone State have been treated to the spectacular sight of the aurora borealis in the evening sky at various times this year, including earlier this October. A strong geomagnetic storm in May also made the northern lights visible as far south as Florida.

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The sun is currently in Solar Cycle 25, a natural cycle it goes through as it transitions between low and high magnetic energy. About every 11 years, at the height of the cycle, the sun’s magnetic poles flip — think of the North and South poles changing places every decade — and the sun transitions from being calm to an active and stormy state, NASA explained.

“During solar maximum, the number of sunspots, and therefore, the amount of solar activity, increases,” Jamie Favors, director of the Space Weather Program at NASA Headquarters in Washington, told reporters. “This increase in activity provides an exciting opportunity to learn about our closest star — but also causes real effects at Earth and throughout our solar system.”

Solar activity strongly influences space weather, which can affect everything from satellites and astronauts in space to communications and navigation systems — such as radio and GPS — to power grids on Earth. Intense solar storms in May, which prompted NOAA only second-ever geomagnetic storm warning — knocked out GPS systems on tractors and other farm equipment and caused some other minor glitches, but largely would have gone unnoticed if not for a spectacular northern lights display that NASA said was possibly the strongest on record in 500 years.

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“Lady Aurora,” as the phenomenon of the aurora borealis is sometimes called, danced around the world in May after a barrage of solar flares and coronal mass ejections (CMEs) created the strongest geomagnetic storm in two decades.

The most powerful flare of Solar Cycle 25 so far was an X9.0 on Oct. 3 (X-class denotes the most intense flares, while the number provides more information about its strength). People in each of the 48 lower states saw the northern lights as a result.

Solar Cycle 25 sunspot activity has “slightly exceeded” experts’ expectations, Lisa Upton, co-chair of the Solar Cycle Prediction Panel and lead scientist at Southwest Research Institute in San Antonio, Texas, said at the teleconference. “However, despite seeing a few large storms, they aren’t larger than what we might expect during the maximum phase of the cycle.”

NOAA said additional solar and geomagnetic storms are likely during the solar maximum period. That doesn’t mean the aurora won’t dip beyond its typical Arctic range after solar maximum has passed. Although less frequently, scientists see fairly significant storms during the declining phases of a solar cycle.

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“This announcement doesn’t mean that this is the peak of solar activity we’ll see this solar cycle,” Elsayed Talaat, director of space weather operations at NOAA, told reporters. “While the Sun has reached the solar maximum period, the month that solar activity peaks on the Sun will not be identified for months or years.”

Although the peak of solar maximum is only identifiable after scientists have tracked a consistent decline in solar activity after the peak, scientists say the last two years have been part of this active phase of the solar cycle, due to the consistently high number of sunspots during the period.

The active phase should last another year or so before the sun heads back to the quiet phase known as “solar minimum.”