Tag Archives: solar maximum

Solar Cycles

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The Termination Event

/ Dr.Tony Phillips

June 10, 2021: Something big may be about to happen on the sun. “We call it the Termination Event,” says Scott McIntosh, a solar physicist at the National Center for Atmospheric Research (NCAR), “and it’s very, very close to happening.”

If you’ve never heard of the Termination Event, you’re not alone.  Many researchers have never heard of it either. It’s a relatively new idea in solar physics championed by McIntosh and colleague Bob Leamon of the University of Maryland – Baltimore County. According to the two scientists, vast bands of magnetism are drifting across the surface of the sun. When oppositely-charged bands collide at the equator, they annihilate (or “terminate”). There’s no explosion; this is magnetism, not anti-matter. Nevertheless, the Termination Event is a big deal. It can kickstart the next solar cycle into a higher gear.

Above: Oppositely charged magnetic bands (red and blue) march toward the sun’s equator where they annihilate one another, kickstarting the next solar cycle. [full caption]

“If the Terminator Event happens soon, as we expect, new Solar Cycle 25 could have a magnitude that rivals the top few since record-keeping began,” says McIntosh.

This is, to say the least, controversial. Most solar physicists believe that Solar Cycle 25 will be weak, akin to the anemic Solar Cycle 24 which barely peaked back in 2012-2013. Orthodox models of the sun’s inner magnetic dynamo favor a weak cycle and do not even include the concept of “terminators.”

“What can I say?” laughs McIntosh. “We’re heretics!”

The researchers outlined their reasoning in a December 2020 paper in the research journal Solar Physics. Looking back over 270 years of sunspot data, they found that Terminator Events divide one solar cycle from the next, happening approximately every 11 years. Emphasis on approximately. The interval between terminators ranges from 10 to 15 years, and this is key to predicting the solar cycle.

Above: The official forecast for Solar Cycle 25 (red) is weak; McIntosh and Leamon believe it will be more like the strongest solar cycles of the past.

“We found that the longer the time between terminators, the weaker the next cycle would be,” explains Leamon. “Conversely, the shorter the time between terminators, the stronger the next solar cycle would be.”

Example: Sunspot Cycle 4 began with a terminator in 1786 and ended with a terminator in 1801, an unprecedented 15 years later. The following cycle, 5, was incredibly weak with a peak amplitude of just 82 sunspots. That cycle would become known as the beginning of the “Dalton” Grand Minimum.

Solar Cycle 25 is shaping up to be the opposite. Instead of a long interval, it appears to be coming on the heels of a very short one, only 10 years since the Terminator Event that began Solar Cycle 24. Previous solar cycles with such short intervals have been among the strongest in recorded history.

These ideas may be controversial, but they have a virtue that all scientists can appreciate: They’re testable. If the Termination Event happens soon and Solar Cycle 25 skyrockets, the “heretics” may be on to something. Stay tuned for updates.

from:    https://spaceweatherarchive.com/2021/06/11/the-termination-event/

Solar Cycle Analysis

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Solar Cycle Update: Twin Peaks

March 1, 2013: Something unexpected is happening on the sun.  2013 is supposed to be the year of Solar Max, the peak of the 11-year sunspot cycle. Yet 2013 has arrived and solar activity is relatively low.  Sunspot numbers are well below their values in 2011, and strong solar flares have been infrequent for many months.

The quiet has led some observers to wonder if forecasters missed the mark. Solar physicist Dean Pesnell of the Goddard Space Flight Center has a different explanation:

“This is solar maximum,” he suggests. “But it looks different from what we expected because it is double peaked.”

Twin Peaks (splash)

A new ScienceCast video explores the puzzling behavior of ongoing Solar Cycle 24. Play it

Conventional wisdom holds that solar activity swings back and forth like a simple pendulum.  At one end of the cycle, there is a quiet time with few sunspots and flares.  At the other end, Solar Max brings high sunspot numbers and solar storms. It’s a regular rhythm that repeats every 11 years.

Reality, however, is more complicated. Astronomers have been counting sunspots for centuries, and they have seen that the solar cycle is not perfectly regular. For one thing, the back-and-forth swing in sunspot counts can take anywhere from 10 to 13 years to complete; also, the amplitude of the cycle varies.  Some solar maxima are very weak, others very strong.

Pesnell notes yet another complication: “The last two solar maxima, around 1989 and 2001, had not one but two peaks.”  Solar activity went up, dipped, then resumed, performing a mini-cycle that lasted about two years.

The same thing could be happening now.  Sunspot counts jumped in 2011, dipped in 2012, and Pesnell expects them to rebound again in 2013: “I am comfortable in saying that another peak will happen in 2013 and possibly last into 2014,” he predicts.

Another curiosity of the solar cycle is that the sun’s hemispheres do not always peak at the same time.  In the current cycle, the south has been lagging behind the north.  The second peak, if it occurs, will likely feature the southern hemisphere playing catch-up, with a surge in activity south of the sun’s equator.

Twin Peaks (shortfall, med)

Recent sunspot counts fall short of predictions. Credit: Dr. Tony Philips & NOAA/SWPC [full plot]

Pesnell is a leading member of the NOAA/NASA Solar Cycle Prediction Panel, a blue-ribbon group of solar physicists who assembled in 2006 and 2008 to forecast the next Solar Max. At the time, the sun was experiencing its deepest minimum in nearly a hundred years.  Sunspot numbers were pegged near zero and x-ray flare activity flat-lined for months at a time.  Recognizing that deep minima are often followed by weak maxima, and pulling together many other threads of predictive evidence, the panel issued this statement:

“The Solar Cycle 24 Prediction Panel has reached a consensus. The panel has decided that the next solar cycle (Cycle 24) will be below average in intensity, with a maximum sunspot number of 90. Given the date of solar minimum and the predicted maximum intensity, solar maximum is now expected to occur in May 2013. Note, this is not a unanimous decision, but a supermajority of the panel did agree.”

Given the tepid state of solar activity in Feb. 2013, a maximum in May now seems unlikely.

“We may be seeing what happens when you predict a single amplitude and the Sun responds with a double peak,” comments Pesnell.

Incidentally, Pesnell notes a similarity between Solar Cycle 24, underway now, and Solar Cycle 14, which had a double-peak during the first decade of the 20th century. If the two cycles are in fact twins, “it would mean one peak in late 2013 and another in 2015.”

No one knows for sure what the sun will do next.  It seems likely, though, that the end of 2013 could be a lot livelier than the beginning.
Author: Dr. Tony Phillips

from:    http://science.nasa.gov/science-news/science-at-nasa/2013/01mar_twinpeaks/

Solar Storm Heated Up the Atmosphere

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Solar Storm Dumps Gigawatts into Earth’s Upper Atmosphere

Play ScienceCast Video

March 22, 2012:  A recent flurry of eruptions on the sun did more than spark pretty auroras around the poles.  NASA-funded researchers say the solar storms of March 8th through 10th dumped enough energy in Earth’s upper atmosphere to power every residence in New York City for two years.

“This was the biggest dose of heat we’ve received from a solar storm since 2005,” says Martin Mlynczak of NASA Langley Research Center.  “It was a big event, and shows how solar activity can directly affect our planet.”

Solar Storms Dumps Gigawatts (splash)

Earth’s atmosphere lights up at infrared wavelengths during the solar storms of March 8-10, 2010. A ScienceCast video explains the physics of this phenomenon. Play it!

Mlynczak is the associate principal investigator for the SABER instrument onboard NASA’s TIMED satellite.  SABER monitors infrared emissions from Earth’s upper atmosphere, in particular from carbon dioxide (CO2) and nitric oxide (NO), two substances that play a key role in the energy balance of air hundreds of km above our planet’s surface.

“Carbon dioxide and nitric oxide are natural thermostats,” explains James Russell of Hampton University, SABER’s principal investigator.  “When the upper atmosphere (or ‘thermosphere’) heats up, these molecules try as hard as they can to shed that heat back into space.”

That’s what happened on March 8th when a coronal mass ejection (CME) propelled in our direction by an X5-class solar flare hit Earth’s magnetic field.  (On the “Richter Scale of Solar Flares,” X-class flares are the most powerful kind.)  Energetic particles rained down on the upper atmosphere, depositing their energy where they hit.  The action produced spectacular auroras around the poles and significant1 upper atmospheric heating all around the globe.

“The thermosphere lit up like a Christmas tree,” says Russell.  “It began to glow intensely at infrared wavelengths as the thermostat effect kicked in.”

For the three day period, March 8th through 10th, the thermosphere absorbed 26 billion kWh of energy.  Infrared radiation from CO2 and NO, the two most efficient coolants in the thermosphere, re-radiated 95% of that total back into space.

Solar Storms Dumps Gigawatts (Nitric Oxide Spike, 558px))

A surge of infrared radiation from nitric oxide molecules on March 8-10, 2012, signals the biggest upper-atmospheric heating event in seven years. Credit: SABER/TIMED. See also the CO2 data.

In human terms, this is a lot of energy.  According to the New York City mayor’s office, an average NY household consumes just under 4700 kWh annually. This means the geomagnetic storm dumped enough energy into the atmosphere to power every home in the Big Apple for two years.

“Unfortunately, there’s no practical way to harness this kind of energy,” says Mlynczak.  “It’s so diffuse and out of reach high above Earth’s surface.  Plus, the majority of it has been sent back into space by the action of CO2 and NO.”

During the heating impulse, the thermosphere puffed up like a marshmallow held over a campfire, temporarily increasing the drag on low-orbiting satellites.  This is both good and bad.  On the one hand, extra drag helps clear space junk out of Earth orbit.  On the other hand, it decreases the lifetime of useful satellites by bringing them closer to the day of re-entry.

The storm is over now, but Russell and Mlynczak expect more to come.

“We’re just emerging from a deep solar minimum,” says Russell.  “The solar cycle is gaining strength with a maximum expected in 2013.”

More sunspots flinging more CMEs toward Earth adds up to more opportunities for SABER to study the heating effect of solar storms.

“This is a new frontier in the sun-Earth connection,” says Mlynczak, and the data we’re collecting are unprecedented.”

from:    http://science.nasa.gov/science-news/science-at-nasa/2012/22mar_saber/