AC5E on Sunspots and Climate
(From the April 2004 Zero Beat, the Journal of the Hattiesburg Amateur Radio Club)
According to the news of the dubious, one boffin says the next sunspot cycle will be extremely intense, perhaps even exceeding the 1956 maxima. Historically, intense sunspot cycles have started early, peaked fast, and lingered a while!
Glossing much over and leaving much out, if that prediction is true the sun's magnetic field should reverse and signal the end of this sunspot half cycle just any day now.
By mid 2008 we should be enjoying propagation much like we had in 2001, and by late 2010 the sunspot average should be in the 250 to 300 range. Maybe even higher!
I hope so, since I would like to see ten meters open 24 hours a day for weeks on end one more time. I would sure make an effort to make the DX Honor Roll if it did. But I am fairly certain those who expect lotsa spots and great HF propagation between 2008 and 2013 will be sorely disappointed.
The why is pretty simple. The sun has had active periods for billions of years. NASA used radiocarbon concentrations, tree ring analysis, and other physics based methods to reconstruct sunspot cycles going back some 11,000 years. The bottom line - sunspot activity for the last half century has been exceptional.
You would have to set your time machine at 6,000 BC (8,000 BP or before present) in order to see the sun as active as it has been lately. Worse, from a potential propagation standpoint, the earlier intense periods were shorter than this one.
So, historically speaking, it's past time for this period of intense sunspot activity and equally intense HF propagation to come to an end. Similar periods of the past ended with a whimper, not a bang. So I expect the future to be much like the past, and the sunspots to gradually fade away to nothing.
Prophecy is a chancy profession, and Cassandra deserved the kicking she got. But I will stick my neck out far enough to categorically state that I expect to see the Smoothed Sunspot Average peak between 75 and 90 somewhere in the next four to seven years. And I will be both pleased and amazed if we actually get an SSA between 250 and 300!
Propagation tracks sunspots, and if things follow their wonted course, we can expect comparatively poor propagation on all the HF bands above 15 MHz at the peak of the next cycle. Ten and 12-Meter openings in particular are likely to be of short duration, with 17 and 20 Meters only open a few hours a day. That makes it doubly important that we protect our lower HF bands from any sort of man made interference!
Now, propagation is not the only thing sunspots affect. The climate is also strongly affected by sunspot activity.
The Chinese have been keeping both sunspot and climate records for more than 2,000 years. They have recorded three periods of high to extremely high sunspot activity. The first was about the time Hadrian built a wall across England, roughly 150 AD. The second was some 900 years later, around 1050 to 1100. The third?
That waited another 900 some years, starting in the mid 1940's and lasting at least until the end of the current sunspot cycle. I remember when the last intense cycle literally erupted, bringing very bright aurora almost to the southern horizon at Moultrie Georgia in late 1952 and setting an all time sunspot average high in 1957.
Every solar maxima since the 1957 big 'un has been weaker but still well above the 2000 year average of peak spot count. In fact, while the last maxima was much tamer than the four immediately before it, it was still 50 percent above the "2,000 year average."
That mirrors the pattern of the last two intense maxima, and it is almost certain that the decline in sunspot numbers will follow the historical pattern.
So does the sunspot cycle impact the climate? Indeed it does.
Those 2000 year old Chinese records show rivers thawed earlier, snow melted sooner, crops sprouted earlier and yielded more, and the climate is much milder during the 10 percent of the time the sun was most active. That same pattern has occurred every time we have a sunspot super maxima.
Why? Because Ol' Sol's total emissions, including heat, increase at the height of each sunspot cycle, and increase even more and for a longer period during each sunspot super maxima.
According to the most widely accepted estimates I can find, total solar emissions increased by some two percent between 1800 and 1980, with virtually all the increase coming after 1920. Total solar emissions were flat or declined slightly since the mid 1980's.
Two percent sounds as if a 100-degree day in 1800 would be a 102-degree day now. But if our planet wandered away from our star the surface temperature would soon be close to 450 degrees below zero. We are most comfortable around 70 degrees, so that makes 520 degrees between no sun and comfortable.
Two percent of that is over 10 degrees. So if other factors did not intervene, the average temperature of our planet should have been 10 degrees warmer in 1990 than it was in 1800.
It was not, but the reasons are well known - more solar radiation causes more evaporation, causing more clouds, raising the "albedo" or the apparent brightness of the earth, causing more radiation to be reflected back into space. And while all this may be interesting, the sunspot cycle's effects on history is fascinating.
Warm and cold cycles strongly affect trade routes and tribal migrations, as trade goods and foodstuffs become more available during warm periods and scarcer during cold ones.
Even casual examination of trade routes and mass migrations tells the story of global warming and cooling, but analyzing data is dry work. So for the moment, let me observe that the quickest path to understanding is often the crooked path and take a detour. Let's go from total solar emissions and the effect of a higher albedo to history; starting with today's headlines.
Today's headlines say Greenland's glaciers are melting, Greenland's glaciers are melting, New York will drown before 2100.
Greenland's glaciers have certainly melted before, in the 10th and 11th centuries when Lief Ericsson was selling farmsteads in with all the fervor of a 1920's Florida real estate boomer.
Greenland's glaciers probably melted around 150 AD when Hadrian was going into the construction business. But if anyone visited during that time they didn't brag about it. But exiles and outcasts don't usually go home and brag, you know.
Greenland's glaciers were almost certainly much smaller when the prehistoric Red Ochre People occupied the great arc of land and sea between the St. Laurence River and the Baltic.
In chronological order, the Red Ochre People disappeared (the Vinland expedition's "Skraelings" may have been a remnant population), most probably during one of the more intense "mini ice ages" dendrology (tree ring analysis) tells us of.
Assyrian records that correspond to a period of persistently low sunspot numbers report seven years of crop failures and famine due to late springs, dry summers, and early winters, while 300 years later the spots returned and the climate was much more salubrious, with early springs, mild winters, and summer rain.
So even before the Chinese started keeping records the sun's cycles had an effect on humanity. And the climate, as the widely spaced rings from warm periods alternating with closely spaced rings from the long cold spells attest, changed with the spots.
Historically, and more familiarly, Hadrian's wall builders complained of fog and rain and wrote home for socks! Tree rings and other evidence from the era show widely spaced rings, and clear evidence of a climate at least as mild as today's.
600 years later the Venerable Bede mentions bitter cold, with rivers frozen hard enough to support riders from early October to March as far south as Hastings and Penzance. As far south as you can get in England. Unless you wear scales and can swim.
Another three hundred years brings us to the eleventh century, which began with Eric the Red's stumbling across what he called Greenland. The glaciers were in retreat and Eric and his crew found wild grapes, wheat, and willow trees. Probable evidence of earlier colonization, most likely by the Red Ochre people!
Eric returned to Iceland and promptly took up land booming for a living! And did well at it, attracting many families who wanted to settle in a vast new land.
The warm spell was nearing its end by September 25, 1066, when brutally hot September weather impelled Harald Hardraada's Danes to discard their quilted hauberks and chain mail at Stamford Bridge. Unarmored, the well rested Danes were slaughtered by Harold's Saxons, even though the Saxons were exhausted from an incredible 180 mile, four day forced march! (230 miles in three and a half days according to some historians!)
Four days after Stamford Bridge summery weather helped William the Bastard, son of Robert the Devil and a blacksmith's daughter, land men and supplies on English soil near Hastings.
Three warm weeks after Stamford Bridge Harold and William's armies met near Hastings, Harold took an arrow in his eye, and Bill the Bastard became "the Conqueror!"
After William's accession the climate cooled, until a 13th century mini-ice age crowned famine king from Italy's boot northward. Greenland's settlers either starved or faded into the native Inuit population as extreme cold made farming impossible.
Just two hundred years later, the sunspots strengthened and northern soils once again yielded their "bounteous fruits," or at least as bounteous as Night soil and wooden plows yielded.
With increased food supplies European civilization bloomed into the glorious Renaissance, quickly followed by the voyages of exploration and colonization which took advantage of the all too temporary warmth. Including the colonization of America.
Then another mini-ice age came along. American rivers as far down the coast as South Carolina froze solidly enough that settlers cut and banked ice against the next summer’s heat. Then came our Revolution - still cold, and soldier’s feet froze at Valley Forge.
But by the time of the War Between the States, the climate was somewhat milder. A slow trend that continued for the next 80 years. Then, around 1945 Ol' Sol broke out with a near record case of sunpox, and the weather became milder than it had been in a thousand years! Followed by the all time solar maxima of 1956 and '57 and a warming trend that has continued, perhaps to this day.
Or perhaps it has not. There are many indications that our climate may be actually cooling quite rapidly. Including the fact that Greenland's glaciers are growing in some places.
Last winter was an extremely severe winter over most of the Northern Hemisphere. Snow loads collapsed hundreds of European and Russian buildings, with severe loss of life in Germany, Poland, and Russia. The worst winter since the "Long March" hit China. Japan was socked with the most severe winter since the 1930's.
All told, last winter had the lowest temperatures over the widest area in more than seventy years. North America escaped the worst of it, but we are getting plenty of cold late winter weather. Several fiftyish people told me this winter was the coldest they can remember. I probably remember worse - but I'm an antique, so I have a right!
To sum it up, we have just gone through the most intense periods of solar activity in recorded history. By all the signs and portents, the sun was at its most energetic beginning in the 1950's and it's been radiating far more energy than the 2,000 year average ever since.
It seems inevitable there will be a decline in solar radiation. And according to NASA's 11,000 year long look at the past and at least 3,000 years of written history, that decline is past due.
Confirming that, the overall level of solar energy impinging on our planet has declined slightly over the last decade and will most likely drop by a half percent or so in the next 50 years.
A half- percent drop in solar radiation represents two degrees F, a degree Celsius, more or less. That's just about the increase in global temperatures that have occurred since 1930. So short term, we can expect temperatures much like that of the 1900-1930 time period. Brrr - get your steam heated long johns ready!
But what about global warming? Are we really about to turn the Earth into it's near twin Venus. Several scientists say the Earth's albedo is much lower than it should be, partially because of particulate pollution (mostly smoke and dust from Asia) and partially because the Tunguska event disrupted the upper atmosphere enough to drastically thin out the cirrus clouds that reflect most of the solar heat back to space.
There is no doubt of the pollution that is visible from the International Space Station. The Tunguska event is more doubtful. But either way, yes, we should clean up our mess. We need to stop using up our limited supply of fossil fuels, and we should clean up our landfills and recycle as much as possible.
I have talked about that before, but we absolutely cannot become energy independent over Night without condemning fifty to one hundred million Americans to a miserable death from heat, cold, thirst, or famine.
Despite the posturings of a few billionaire politicians, the government has a responsibility to keep the heat on, the air conditioners running, and the water taps flowing. So what do we do? The very best we can to cut total energy use, as quickly as we can. Given the will, we could get to 100 percent recycled fuels, cutting our output of atmospheric carbon dioxide and other pollutants, in about 30 years. And there's a question whether India, China, Indonesia, and the other newly emerging industrial nations can do it at all. Or are even willing to try.
So, while the "man made global warming" enthusiasts in both the media and in academia have managed to apply sufficient pressure to silence most critics, I will cheerfully play Cassandra again.
The way the portents are stacking up, twenty solar cycles from now the Earth is likely to get weather much like it had during the "little ice age" of the 13th and 14th centuries. Cold, cold, cold, cold! And with equally chilly HF propagation.
Anybody want to invest in energy futures? Or lobby for more ham bandwidth in the VLF region?