Divide by Zero
The Living Force
An interesting article about how we may be moving into weaker solar activity. which explains a factor that may bring in the next little ice age.
From:
http://www.earthfiles.com/news.php?ID=1907&category=Science
Interview:
David Hathaway, Ph.D.,NASA Solar Physicist.
David Hathaway, Ph.D., Solar Physicist, NASA Marshall Space Flight Center, Huntsville, Alabama: “A Grand Minimum is a possibility because we know the sun has done
it before. In fact, part of understanding the sunspot number going back 400 years is to get observations just before the solar Maunder Minimum of 1635 to 1715. There was one Portuguese sun watcher in the 1630s who counted sunspots and left a record that indicates the sunspot cycles got smaller and smaller as they went into that 80-year Maunder Minimum of no sunspots. For the last two to three decades, we've been seeing a slow decline in the number of sunspots in the last few solar cycles.”
[ Editor's Note: Wikipedia - The Maunder Minimum (also known as the prolonged sunspot minimum) is the name used for the period roughly spanning 1645 to 1715 when sunspots became exceedingly rare, as noted by solar observers of the time. Like the Dalton Minimum and Spörer Minimum, the Maunder Minimum coincided with a period of lower-than-average global temperatures and with the middle — and coldest part — of the Little Ice Age, during which Europe and North America were subjected to bitterly cold winters.
A causal connection between low sunspot activity and cold winters emerged recently in data from NASA's Solar Radiation and Climate Experiment which shows that solar UV output is more variable over the course of the solar cycle than scientists had previously thought. See: October 9, 2011 Nature Geoscience. During one 30-year period within the Maunder Minimum, astronomers observed only about 50 sunspots, as opposed to a more typical 40,000-50,000 spots in modern times.
Since around 1749, continuous monthly averages of sunspot activity have been available
and reported here by the Solar Influences Data Analysis Center, World Data Center for the Sunspot Index, at the Royal Observatory of Belgium. These figures are based on an
average of measurements from many different observatories around the world.
Prior to 1749, sporadic observations of sunspots are available.
Normal 11-year solar magnetic cycles (blue) are supposed to have rising and lowering numbers of sunspots. But during the 80-year-long Maunder Minimum (red), few sunspots were observed and the period overlapped with the Little Ice Age. In the 1800s, lower sunspot numbers returned called the Dalton Minimum. Then by the 1950s, higher numbers of sunspots is called the Modern Maximum. Unsettled is the question: does low sunspot activity cause cooler temperatures on Earth? Graph by Robert A. Rohde/Global Warming Art Project.]
David Hathaway, Ph.D.: “So, the primary purpose of the Sunspot, New Mexico, meeting was to learn more about sunspot numbers going back to Galileo’s time some 400 years ago. Shortly after telescopes were used to see the sun, one of the first things that Galileo and others noticed were sunspots. So we have observations going back to 1610. The problem is that you get a different count depending on how good your telescope is, what the sky is like on the day you are observing, and other variabilities.
That's why back in the mid-1800s, the Director of the Observatory in Zurich, Switzerland, Rudolph Wolf, decided it was much easier to identify groups of spots. You can count the number of groups with even a poor telescope and then add the number of spots. So, he came up with the ‘Relative Sunspot Number.’ We’ve been using that since his time in 1849, but there has been some other funny business with the sunspot number. (laughs)
1945 Secret Change in Sunspot Counting
Apparently in 1945 after WWII, a new director of the Swiss Federal Observatory, Max Waldmeier, secretly changed the method of counting sunspots. I was shocked when I heard this, but it is definitely true that Waldmeier started counting the number of sunspot groups, then multiplied by 10 and added up the number of spots. But he also decided that every spot was not equal. Little spots each count for 1, and if the spots are bigger, they can count for 2, 3, even up to 5. Waldmeier's system would make the number of sunspots bigger - inflated by maybe 20%!
This is interesting because since the Maunder Minimum ended in about 1715, it appeared that the sunspot cycles were slowly getting bigger and bigger. In fact, from the mid-20th Century onward, it has been called the Maunder Maximum. It looked like we had all these huge sunspot cycles starting about 1945. (laughs) But if you take into account the inflation of the sunspot number that Max Waldmeier introduced, it looks like we had similarly large cycles in the 1800s and the 1700s.
So, the whole idea that the sun has been far more active now than it was – some would say – for thousands of years – gets called into question by the fact that sunspot numbers were inflated by Waldmeier.
If Sun Goes Into Grand Minimum, What Happens?
BUT IT DOES NOT CHANGE THE MAJOR QUESTION: IS THE SUN SORT OF WINDING DOWN IN ITS SOLAR CYCLES TO A PERIOD IN WHICH THERE WON’T BE ANY SUNSPOTS? IF SO, WHAT HAPPENS?
That’s right. It doesn’t change that at all. At the meeting, it was Bill Livingston and Matt Penn who said it looks like sunspots are getting weaker. It looks like there were fewer small sunspots during Cycle 23 than there should have been in proportion to the large spots if you go back and compare to previous cycles.
Sunspots in their darkest part seem to be getting brighter and the strength of sunspot magnetic fields are getting weaker. That has been an interesting trend over the end of Cycle 23 and seems to be continuing into Cycle 24. But we need more time to get to the bottom of that as well.
Sunspot magnetic fields declining, measured by Bill Livingston and Matt Penn
of the National Solar Observatory (NSO) in Tucson, Arizona, from 1992 - Feb. 2009,
using an infrared Zeeman splitting technique. Source: Livingston and Penn,
EOS, American Geophysical Union, Vol. 90, No. 30, July 28, 2009.
[ Eos is Greek goddess of dawn - the AGU geophysical research contributing
to understanding Earth and its space environment.]
[ Editor's Note: At the time of the July 28, 2009, EOS paper, solar physicist Matt Penn reported, “Sunspot magnetic fields are dropping by about 50 gauss per year. If we extrapolate this trend into the future, sunspots could completely vanish around the year 2015. According to our measurements, sunspots seem to form only if the magnetic field is stronger than about 1500 gauss. If the current trend continues, we'll hit that threshold in the near future, and solar magnetic fields would become too weak to form sunspots.” ]
Since this Cycle 24 is significantly smaller than the last cycle (Cycle 23), which peaked in 2000 and that was smaller than the cycle prior to it (Cycle 22), we are wondering if there is a downward trend into a Grand Minimum and this Solar Cycle 24 is the last with sunspots for decades to come? But I would like to know what Cycle 25 looks like and we won't know that until well after Cycle 24 reaches its maximum around the middle of 2013.
IF THIS CYCLE 24 IS THE LAST ONE WITH A SUNSPOT CYCLE FOR THE FORESEEABLE FUTURE, WHAT DO YOU ALL THINK WOULD HAPPEN ON THE EARTH?
The good news is that big flares that can take out satellites and disrupt communications here on Earth - all of that would be lessened. If the sun goes into a Grand Minimum that could help answer the question about how much the sun is involved in global warming.
How Will We Know Solar Cycle 25 Has Started?
The high latitudes on the sun start rotating a little faster than normal and that appears to have happened during the last couple of cycles – again a year or two before the maximum of the cycle. Then it seems to lead into a rapidly rotating flow feature that moves towards the equator during the next cycle.
There’s also high latitude coronal emissions. The corona is the sun’s hot outer atmosphere and there are high latitude features – features near the poles that move off towards the poles at about the time of sunspot cycle maximum. Often we see the beginning of that a year or two before maximum. We haven’t seen that yet either.
IF NEITHER OF THOSE TWO SIGNALS OF SOLAR CYCLE 25 HAVE SHOWED UP BY SAY SEPTEMBER OR OCTOBER 2013, WHAT WOULD YOU ALL BE REPORTING THEN?
I think you would have more people on the bandwagon saying it looks like the sun is doing something strange here and going into a Grand Minimum like we haven’t seen since the end of the Maunder Minimum in 1715.
IF IT GOES INTO A GRAND MINIMUM, DOES THAT MEAN THAT EUROPE GOES BACK INTO AN ICE AGE?
I wouldn’t say that. There’s still uncertainty here, but this is a huge question for the sun: how big a player is the sun in global climate change? Does the sun's contribution come in at the 10% level? Or at the 50% level? Or even higher? I don’t think we know.
SINCE THE SUN IS THE ONLY SOURCE OF HEAT FOR THE ENTIRE SOLAR SYSTEM, WHY WOULDN’T THE SUN BE A MAJOR PLAYER IN CLIMATE CHANGE?
It’s how variable is it? Sure, a dimmer sun would make a cooler Earth, but there is a huge temperature change on the Earth that’s caused by the greenhouse effect. The fact that you have this atmosphere that traps heat and without that effect, we would not be able to survive on Earth. So there’s a big part played by our atmosphere.
The problem in understanding the connection with global warming is how much does the sun vary? And we know its total output – how bright it is, how much energy hits the Earth’s upper atmosphere. That only changes by one-tenth of 1% over the course of a sunspot cycle. It’s dim at minimum and bright at maximum, but the change in the sun's energy on Earth is only one-tenth of 1%.
If the sun is a bigger player, it can’t just be through how bright it is. That cannot explain the size of the temperature variations that we see. That’s why people look at other effects – like the sun’s effects on cloud creation here through cosmic rays or the sun’s affect on the chemistry and dynamics of the upper atmosphere through its variations not in total radiance, but in spectral radiance. How bright is it in the ultraviolet that influences the Earth’s upper atmosphere? We know those are big changes.
This is where the line of research is at the moment: how do those variations in the sun’s ultraviolet brightness – how does that feed into climate? How do cosmic rays and possible cloud formation feed into climate? That’s where the current research is, but we don’t have an answer.
Ice Ages and Milankovitch Cycles
WHAT CAUSES ICE AGES AND EVEN PERIODS WHEN THE ENTIRE EARTH WAS ENCASED IN ICE?
Some of that is fairly well understood. They are called Milankovitch cycles.
A Milankovitch Cycle is related to the Earth’s orbit around the Sun.
One complete cycle lasts for about 100,000 years. There are three cycles of
Eccentricity (E), axial Tilt (T), and Precession (P). According to the Milankovitch
Theory, these three cycles combine to affect the amount of solar heat
on the Earth’s surface and subsequent influence on climate.
We're going into winter now for the Northern Hemisphere. That's when the Earth’s rotation axis of the North Pole is pointed away from the sun. So ironically, when we’re in winter, the Earth’s orbit is closer to the sun. That kind of moderates Northern Hemisphere winters.
There’s another phase of this, though, when it’s the other way around. That's when we’re farther away from the sun during Northern Hemisphere winter and that makes the winters even more severe and more apt to build ice.
BETWEEN NOW AND 2013, WHAT WILL YOU AND OTHER SOLAR PHYSICISTS BE DOING?
I’m still trying to figure out how the sun makes sunspot cycles to begin with! (laughs) We’ve had this many decades-long saga about trying to understand how the sun does it. For the last decade and a half or so, we thought we had it figured out. Then I’ve been finding out over the past two years -no! What we thought was right cannot be right. I know it can’t be right.
If Solar Cycle 25 starts and continues without sunspots, you’re not going to have to wait to hear about it. I think you will hear about it long before mid-2013.”
From:
http://www.earthfiles.com/news.php?ID=1907&category=Science
Interview:
David Hathaway, Ph.D.,NASA Solar Physicist.
David Hathaway, Ph.D., Solar Physicist, NASA Marshall Space Flight Center, Huntsville, Alabama: “A Grand Minimum is a possibility because we know the sun has done
it before. In fact, part of understanding the sunspot number going back 400 years is to get observations just before the solar Maunder Minimum of 1635 to 1715. There was one Portuguese sun watcher in the 1630s who counted sunspots and left a record that indicates the sunspot cycles got smaller and smaller as they went into that 80-year Maunder Minimum of no sunspots. For the last two to three decades, we've been seeing a slow decline in the number of sunspots in the last few solar cycles.”
[ Editor's Note: Wikipedia - The Maunder Minimum (also known as the prolonged sunspot minimum) is the name used for the period roughly spanning 1645 to 1715 when sunspots became exceedingly rare, as noted by solar observers of the time. Like the Dalton Minimum and Spörer Minimum, the Maunder Minimum coincided with a period of lower-than-average global temperatures and with the middle — and coldest part — of the Little Ice Age, during which Europe and North America were subjected to bitterly cold winters.
A causal connection between low sunspot activity and cold winters emerged recently in data from NASA's Solar Radiation and Climate Experiment which shows that solar UV output is more variable over the course of the solar cycle than scientists had previously thought. See: October 9, 2011 Nature Geoscience. During one 30-year period within the Maunder Minimum, astronomers observed only about 50 sunspots, as opposed to a more typical 40,000-50,000 spots in modern times.
Since around 1749, continuous monthly averages of sunspot activity have been available
and reported here by the Solar Influences Data Analysis Center, World Data Center for the Sunspot Index, at the Royal Observatory of Belgium. These figures are based on an
average of measurements from many different observatories around the world.
Prior to 1749, sporadic observations of sunspots are available.
Normal 11-year solar magnetic cycles (blue) are supposed to have rising and lowering numbers of sunspots. But during the 80-year-long Maunder Minimum (red), few sunspots were observed and the period overlapped with the Little Ice Age. In the 1800s, lower sunspot numbers returned called the Dalton Minimum. Then by the 1950s, higher numbers of sunspots is called the Modern Maximum. Unsettled is the question: does low sunspot activity cause cooler temperatures on Earth? Graph by Robert A. Rohde/Global Warming Art Project.]
David Hathaway, Ph.D.: “So, the primary purpose of the Sunspot, New Mexico, meeting was to learn more about sunspot numbers going back to Galileo’s time some 400 years ago. Shortly after telescopes were used to see the sun, one of the first things that Galileo and others noticed were sunspots. So we have observations going back to 1610. The problem is that you get a different count depending on how good your telescope is, what the sky is like on the day you are observing, and other variabilities.
That's why back in the mid-1800s, the Director of the Observatory in Zurich, Switzerland, Rudolph Wolf, decided it was much easier to identify groups of spots. You can count the number of groups with even a poor telescope and then add the number of spots. So, he came up with the ‘Relative Sunspot Number.’ We’ve been using that since his time in 1849, but there has been some other funny business with the sunspot number. (laughs)
1945 Secret Change in Sunspot Counting
Apparently in 1945 after WWII, a new director of the Swiss Federal Observatory, Max Waldmeier, secretly changed the method of counting sunspots. I was shocked when I heard this, but it is definitely true that Waldmeier started counting the number of sunspot groups, then multiplied by 10 and added up the number of spots. But he also decided that every spot was not equal. Little spots each count for 1, and if the spots are bigger, they can count for 2, 3, even up to 5. Waldmeier's system would make the number of sunspots bigger - inflated by maybe 20%!
This is interesting because since the Maunder Minimum ended in about 1715, it appeared that the sunspot cycles were slowly getting bigger and bigger. In fact, from the mid-20th Century onward, it has been called the Maunder Maximum. It looked like we had all these huge sunspot cycles starting about 1945. (laughs) But if you take into account the inflation of the sunspot number that Max Waldmeier introduced, it looks like we had similarly large cycles in the 1800s and the 1700s.
So, the whole idea that the sun has been far more active now than it was – some would say – for thousands of years – gets called into question by the fact that sunspot numbers were inflated by Waldmeier.
If Sun Goes Into Grand Minimum, What Happens?
BUT IT DOES NOT CHANGE THE MAJOR QUESTION: IS THE SUN SORT OF WINDING DOWN IN ITS SOLAR CYCLES TO A PERIOD IN WHICH THERE WON’T BE ANY SUNSPOTS? IF SO, WHAT HAPPENS?
That’s right. It doesn’t change that at all. At the meeting, it was Bill Livingston and Matt Penn who said it looks like sunspots are getting weaker. It looks like there were fewer small sunspots during Cycle 23 than there should have been in proportion to the large spots if you go back and compare to previous cycles.
Sunspots in their darkest part seem to be getting brighter and the strength of sunspot magnetic fields are getting weaker. That has been an interesting trend over the end of Cycle 23 and seems to be continuing into Cycle 24. But we need more time to get to the bottom of that as well.
Sunspot magnetic fields declining, measured by Bill Livingston and Matt Penn
of the National Solar Observatory (NSO) in Tucson, Arizona, from 1992 - Feb. 2009,
using an infrared Zeeman splitting technique. Source: Livingston and Penn,
EOS, American Geophysical Union, Vol. 90, No. 30, July 28, 2009.
[ Eos is Greek goddess of dawn - the AGU geophysical research contributing
to understanding Earth and its space environment.]
[ Editor's Note: At the time of the July 28, 2009, EOS paper, solar physicist Matt Penn reported, “Sunspot magnetic fields are dropping by about 50 gauss per year. If we extrapolate this trend into the future, sunspots could completely vanish around the year 2015. According to our measurements, sunspots seem to form only if the magnetic field is stronger than about 1500 gauss. If the current trend continues, we'll hit that threshold in the near future, and solar magnetic fields would become too weak to form sunspots.” ]
Since this Cycle 24 is significantly smaller than the last cycle (Cycle 23), which peaked in 2000 and that was smaller than the cycle prior to it (Cycle 22), we are wondering if there is a downward trend into a Grand Minimum and this Solar Cycle 24 is the last with sunspots for decades to come? But I would like to know what Cycle 25 looks like and we won't know that until well after Cycle 24 reaches its maximum around the middle of 2013.
IF THIS CYCLE 24 IS THE LAST ONE WITH A SUNSPOT CYCLE FOR THE FORESEEABLE FUTURE, WHAT DO YOU ALL THINK WOULD HAPPEN ON THE EARTH?
The good news is that big flares that can take out satellites and disrupt communications here on Earth - all of that would be lessened. If the sun goes into a Grand Minimum that could help answer the question about how much the sun is involved in global warming.
How Will We Know Solar Cycle 25 Has Started?
The high latitudes on the sun start rotating a little faster than normal and that appears to have happened during the last couple of cycles – again a year or two before the maximum of the cycle. Then it seems to lead into a rapidly rotating flow feature that moves towards the equator during the next cycle.
There’s also high latitude coronal emissions. The corona is the sun’s hot outer atmosphere and there are high latitude features – features near the poles that move off towards the poles at about the time of sunspot cycle maximum. Often we see the beginning of that a year or two before maximum. We haven’t seen that yet either.
IF NEITHER OF THOSE TWO SIGNALS OF SOLAR CYCLE 25 HAVE SHOWED UP BY SAY SEPTEMBER OR OCTOBER 2013, WHAT WOULD YOU ALL BE REPORTING THEN?
I think you would have more people on the bandwagon saying it looks like the sun is doing something strange here and going into a Grand Minimum like we haven’t seen since the end of the Maunder Minimum in 1715.
IF IT GOES INTO A GRAND MINIMUM, DOES THAT MEAN THAT EUROPE GOES BACK INTO AN ICE AGE?
I wouldn’t say that. There’s still uncertainty here, but this is a huge question for the sun: how big a player is the sun in global climate change? Does the sun's contribution come in at the 10% level? Or at the 50% level? Or even higher? I don’t think we know.
SINCE THE SUN IS THE ONLY SOURCE OF HEAT FOR THE ENTIRE SOLAR SYSTEM, WHY WOULDN’T THE SUN BE A MAJOR PLAYER IN CLIMATE CHANGE?
It’s how variable is it? Sure, a dimmer sun would make a cooler Earth, but there is a huge temperature change on the Earth that’s caused by the greenhouse effect. The fact that you have this atmosphere that traps heat and without that effect, we would not be able to survive on Earth. So there’s a big part played by our atmosphere.
The problem in understanding the connection with global warming is how much does the sun vary? And we know its total output – how bright it is, how much energy hits the Earth’s upper atmosphere. That only changes by one-tenth of 1% over the course of a sunspot cycle. It’s dim at minimum and bright at maximum, but the change in the sun's energy on Earth is only one-tenth of 1%.
If the sun is a bigger player, it can’t just be through how bright it is. That cannot explain the size of the temperature variations that we see. That’s why people look at other effects – like the sun’s effects on cloud creation here through cosmic rays or the sun’s affect on the chemistry and dynamics of the upper atmosphere through its variations not in total radiance, but in spectral radiance. How bright is it in the ultraviolet that influences the Earth’s upper atmosphere? We know those are big changes.
This is where the line of research is at the moment: how do those variations in the sun’s ultraviolet brightness – how does that feed into climate? How do cosmic rays and possible cloud formation feed into climate? That’s where the current research is, but we don’t have an answer.
Ice Ages and Milankovitch Cycles
WHAT CAUSES ICE AGES AND EVEN PERIODS WHEN THE ENTIRE EARTH WAS ENCASED IN ICE?
Some of that is fairly well understood. They are called Milankovitch cycles.
A Milankovitch Cycle is related to the Earth’s orbit around the Sun.
One complete cycle lasts for about 100,000 years. There are three cycles of
Eccentricity (E), axial Tilt (T), and Precession (P). According to the Milankovitch
Theory, these three cycles combine to affect the amount of solar heat
on the Earth’s surface and subsequent influence on climate.
We're going into winter now for the Northern Hemisphere. That's when the Earth’s rotation axis of the North Pole is pointed away from the sun. So ironically, when we’re in winter, the Earth’s orbit is closer to the sun. That kind of moderates Northern Hemisphere winters.
There’s another phase of this, though, when it’s the other way around. That's when we’re farther away from the sun during Northern Hemisphere winter and that makes the winters even more severe and more apt to build ice.
BETWEEN NOW AND 2013, WHAT WILL YOU AND OTHER SOLAR PHYSICISTS BE DOING?
I’m still trying to figure out how the sun makes sunspot cycles to begin with! (laughs) We’ve had this many decades-long saga about trying to understand how the sun does it. For the last decade and a half or so, we thought we had it figured out. Then I’ve been finding out over the past two years -no! What we thought was right cannot be right. I know it can’t be right.
If Solar Cycle 25 starts and continues without sunspots, you’re not going to have to wait to hear about it. I think you will hear about it long before mid-2013.”
