An interesting overview on the two competing theories within NASA on Solar Cycle 24 from amateur solar watcher Tad Cook, also known under his radio ham designation K7RA:
A new forecast is out regarding progress between Solar Cycles 23 and 24. You may recall that the committee of scientists who make a group forecast of future sunspot activity for the NOAA Space Weather Prediction Center were unable to reach a consensus last year, the group evenly split between those who think the next solar cycle will be weak and those that see a stronger solar cycle.
I will refer to the weak cycle predictors as pessimists and strong cycle forecasters as optimists. While these characterizations may not be appropriate for scientists who presumably have no preference either way, as far as Amateur Radio operators are concerned, the high cycle prediction is no doubt the optimistic choice.
The previous prediction appeared in the January 2, 2008, issue 1687 of the Preliminary Report and Forecast. Note on page 8 in the table of predicted smoothed sunspot numbers that the optimistic faction predicts a sunspot minimum of 4 centered around December 2007-April 2008. The pessimistic projection is for a smoothed sunspot number minimum of 3 from January-April 2008.
Now compare this with the prediction ten weeks later on page 9 of issue 1697 from this week. See how the pessimists are now calling for a much longer and lower solar minimum lasting over a year, from November 2007-December 2008. But according to the optimists, the solar minimum has already passed, with a smoothed sunspot number of 6 in August and September 2007 (this generally agrees with our 3-month averages of daily numbers, presented in last week’s bulletin.)
Note there is no split in the value for August 2007. This is because 6 is the known smoothed sunspot number for that month, not a prediction. A year of daily sunspot numbers is required to calculate the smoothed value, and all of the values from mid-February 2007 through mid-February 2008 (a whole year with August in the middle) are known. In fact, enough sunspot data will be known this weekend to fix the smoothed sunspot number for September of last year.
Now look at even better news for sunspot fans. See how the predictions for the peak of the next solar cycle have shifted and both factions see Cycle 24 peaking much higher than they did 10 weeks earlier.
In issue 1687, pessimists predicted a peak between May and October 2012 of only 90, but now in issue 1697, we see a much higher and earlier peak at 124 from August-December 2011, only three and a half years from now. The optimists and pessimists now agree on the timing of the peak, and optimists have upped their peak value prediction from 140 to 154 (access all recent weekly issues here.)
Of course, with only 23 cycles of data to examine, sunspot cycle prediction is still a young science. But new tools unavailable in past decades no doubt have advanced the art.
David Archibald (as reported by Ronald Bailey at Reason magazine):
One of the more remarkable performances was by Australian entrepreneur David C. Archibald during one of the afternoon panels. Archibald is described in the conference materials as “a scientist operating in the fields of cancer research, climate science, and oil exploration.” He also appears to have business interests in some oil fields in Australia. In any case, Archibald made it very clear that he is a big believer in the idea that climate change is primarily driven by the sun. Archibald’s basic theory is that when the sun’s magnetic field strength drops there are fewer sunspots which reduce the amount of particles ejected as the solar wind. Less solar wind allows more galactic cosmic rays to enter the Earth’s atmosphere. Archibald is here relying on studies by Danish physicist Henrik Svensmark which find that cosmic rays do produce cloud condensation nuclei which then might create low level clouds that reflect more sunlight back into space thus making the Earth colder.
Archibald predicts that the next solar cycle, Cycle 24, will produce a weak magnetic field which means that more cosmic rays will enter the atmosphere to create clouds and thus cool the earth. Actually, a 2007 NASA scientific panel was evenly split on the strong/weak prediction for Cycle 24. However, manyresearchers expect that Cycle 25 may be one the weakest in centuries. Archibald ended by boldly predicting that the world will see average temperatures drop by -2.2 degrees centigrade in the coming decade. That’s more than three times the amount of warming the world has experienced over the last century. He also predicted as a consequence that the growing seasons in the United States would be shortened by a total of four weeks, dramatically reducing food production.
Piers Corbyn: astrophysicist and Earth weather predictor at Weather Action (personal communication):
…I would say that solar cycle 24 has NOT yet begun in the sense that we have not yet reached the smoothed minimum normally used to define the transition.
As far as the (Jan 3rd) NASA sighting (’claim’?) of a reverse polarity spot, I don’t suppose there is any doubt that it was seen but I do agree with your implied statement that it doesn’t amount to much.
As a rough estimate we don’t expect any (more/lasting) reverse polarity spots until maybe shortly after mid-March at the earliest.
Paste this into your blog if you wish.
It will be worth referring back to these once SC24 has established itself in whatever form it turns out to be in.
Joe Pappalardo at Popular Mechanics has a fascinating article on the possible (probable?) result of an extended solar minimum such as that which we are experiencing: global cooling:
Every day, scientists hoping to see an increase in solar activity train their instruments at the sun as it crosses the sky. This is no idle academic pursuit: A lull in solar action could potentially drive the planet’s temperature down, or even prompt a mini Ice Age.
Woah! I wonder if Joe has heard about the overwhelming scientific consensus that denies such a result? Maybe I should sic James Hansen on him…
For millennia, thermonuclear forces inside the star have followed a regular rhythm, causing its magnetic field to peak and ebb, on average, every 11 years. Space weathermen are watching for telltale increases in sunspots, which would signal the start of a new cycle, predicted to have started last March and expected to peak in 2012. “When the sun’s active, it’s a little bit brighter,” explains Ken Tapping, a solar researcher and project director for Canada’s National Research Council.
So far, Tapping reports no change in the magnetic field strength, as measured by radio telescopes. On the more positive side, last month NASA reported a small, earth-sized sunspot with a magnetic field pointing in the opposite direction from those in the previous cycle; qualities that designate the spot as a signal of a new upturn in activity. At the solar maximum, scientists expect to see between 75 and 150 such sunspots per day.
Tapping oversees the operation of a 60-year-old radio telescope that he calls a “stethoscope for the sun.” Recent magnetic field readings are as low as he’s ever seen, he says, and he’s worked with the instrument for more than 25 years. If the sun remains this quiet for another a year or two, it may indicate the star has entered a downturn that, if history is any precedent, could trigger a planetary cold spell that could bring massive snowfall and severe weather to the Northern Hemisphere.
The last such solar funk corresponded with a period of bitter cold that began around 1650 and lasted, with intermittent spikes of warming, until 1715. While there were competing causes for the climatic shift—including the Black Death’s depopulation of tree-cutting Europeans and, more substantially, increased volcanic activity spewing ash into the atmosphere—the sun’s lethargy likely had something to do with it.
Of course, no mention of greenhouse gases.
Just how much influence the sun has on global temperatures has been the subject of sometimes acrimonious debate. While an upswing in solar activity may cause a warming trend, it was discounted in the mid-1990s as the sole driver of current climate change. And for anyone hoping that a solar downswing might bail us out of our current dilemma: Solar influence on climate is slight compared to the impact of man-made greenhouse gases, a National Academy of Sciences report concluded in 1995.
Ah, there it is! So what we have is a contest between global warming due to greenhouse gases, and global cooling due to solar dimming.
Its a dilemma as to what to wish for. Global cooling such as the Little Ice Age would have been a technological challenge to modern 21st Century agriculture, technology and energy resources. What’s there to worry about with global warming? Deserts like the Sahara shrinking is a bad thing to be avoided…like the Plague?
In early January 2008, NASA reported the start of Solar Cycle 24 with the sighting of a tiny reversed polarity spot. It lasted three days and then disappeared.
This was reported by Anthony Watts thus:
Solar physicists have been waiting for the appearance of a reversed-polarity sunspot to signal the start of the next solar cycle. The signal for the start of a new cycle is sighting a particular kind of sunspot. That wait is over.
And the NASA blog said:
“On January 4, 2008, a reversed-polarity sunspot appeared—and this signals the start of Solar Cycle 24,” says David Hathaway of the Marshall Space Flight Center.
Above: Images of the first sunspot of Solar Cycle 24 taken by the NASA/ESA Solar and Heliospheric Observatory (SOHO).
Solar activity waxes and wanes in 11-year cycles. Lately, we’ve been experiencing the low ebb, “very few flares, sunspots, or activity of any kind,” says Hathaway. “Solar minimum is upon us.”
But the first announcement of Solar Cycle 24 wasn’t made by NASA in January 2008 - it was actually made by Ulrich Reith on 31 July 2006, with this post:
Last night it seems to have happend, the first sunspot of solar cycle 24 appeard on the southern hemisphere of the sun.
Very close to NOAA 10902 a tiny spot which should be named 10903 appeared at S12W55.
In the SOHO MDI magnetogramms it clearly shows a reversed polarity if compared to the polarity of cycle 23. (cycle 23: black first towards the western limb and white following black / cycle 24: white in front of black)
And I show the picture with an arrow so you know which spot we’re talking about.
Again, the spot persisted for a few days and disappeared.
So what to believe? The transition between one solar cycle and the next is very difficult to call as during the transition both magnetically polarized spots can be seen. The newer cycle spots are usually high latitude (>20o) North and South of the solar equator. Solar cycle 23 spots still continue to produce and any SC24 spots so far are barely a pixel in size and very rare.
Solar cycle 24 remains difficult to call definitively at this time, in my view.
Much excitement from NASA, as the long delayed arrival of Solar Cycle 24 was announced:
Dec. 14, 2007: The solar physics community is abuzz this week. No, there haven’t been any great eruptions or solar storms. The source of the excitement is a modest knot of magnetism that popped over the sun’s eastern limb on Dec. 11th, pictured below in a pair of images from the orbiting Solar and Heliospheric Observatory (SOHO).
It may not look like much, but “this patch of magnetism could be a sign of the next solar cycle,” says solar physicist David Hathaway of the Marshall Space Flight Center.
Yeees, go on…
“New solar cycles always begin with a high-latitude, reversed polarity sunspot,” explains Hathaway. “Reversed polarity ” means a sunspot with opposite magnetic polarity compared to sunspots from the previous solar cycle. “High-latitude” refers to the sun’s grid of latitude and longitude. Old cycle spots congregate near the sun’s equator. New cycle spots appear higher, around 25 or 30 degrees latitude.
OK, got that. Now we have a sunspot with reversed polarity compared to solar cycle 23?
The region that appeared on Dec. 11th fits both these criteria. It is high latitude (24 degrees N) and magnetically reversed. Just one problem: There is no sunspot. So far the region is just a bright knot of magnetic fields. If, however, these fields coalesce into a dark sunspot, scientists are ready to announce that Solar Cycle 24 has officially begun.
And did this coalesce into a sunspot? No. The Sun remains stubbornly blank although there was a fair sized SC23 spot for several days that followed.There appears to be indications of a large sunspot on the far side of the Sun but that too is right on the equator and probably isn’t polarity reversed from SC23.
This isn’t the first time that a sunspot appeared to herald the next solar cycle that failed to materialize. There was another which appeared in late 2006 that got people excited for literally hours when it appeared and disappeared.
Hathaway, it must be remembered, was one of a team who predicted a very strong SC24, at least as strong as the previous one. I think the tension may be getting to him.
I think its OK to actually wait for at least a couple of magnetically reversed sunspots to appear at high latitudes before announcing the Coming of the next Solar Cycle. Whatever happens, SC24 will be late.
NASA is in two minds about the next solar cycle, and so it’s time to place your bets:
You could approach this as a shoot-out between competing hyptheses of solar variation and watch the fun.
Alternatively, you could choose the Modern Science Method:
It could go on for years.
This letter was written to the Greene County Daily:
Each morning I turn on my computer and check to see how the sun is doing. Lately I am greeted with the message “The sun is blank - no sunspots.”
We are at the verge of the next sunspot cycle, solar cycle 24. How intense will this cycle be? Why is this question important? Because the sun is a major force controlling natural climate change on Earth.
Our Milky Way galaxy is awash with cosmic rays. These are high speed charged particles that originate from exploding stars. Because they are charged, their travel is strongly influenced by magnetic fields. Our sun produces a magnetic field that extends to the edges of our solar system. This field deflects many of the cosmic rays away from Earth. But when the sun goes quiet (minimal sunspots), this field collapses inward allowing cosmic rays to penetrate deeper into our solar system. As a result, far greater numbers collide with Earth and penetrate down into the lower atmosphere where they ionize small particles of moisture (humidity) forming them into water droplets that become clouds. Low level clouds reflect sunlight back into space. A large increase in Earth’s cloud cover produce a global drop in temperature.
Some scientist feel they have developed sufficient understanding to predict the intensity of future sunspot cycles. A Solar Cycle 24 Prediction Panel was hosted on 25 April 2007 with officials from NOAA, NASA, ISES and other agencies. They issued a consensus statement which came to the conclusion that the next solar cycle could be severe, peaking at around 140 International Sunspot Numbers (Ri) or moderate, at around 90 Ri. But a few scientist disagree. A number of well regarded solar physicists are predicting the next solar cycle will be far weaker than the last one.
It’s worth pointing out that even NASA is having second thoughts about this, as I pointed out earlier.
A paper by David C. Archibald published in Energy and Environment in 2006 forecasted a low intensity solar cycle with a peak Ri of approximately 50. A few scientist have even claimed that we might be headed into another Solar Minimum. For the past few months, the actual sunspot numbers have been below NOAA’s lower predicted threshold, approaching zero.
And they have continued to be near zero.
Actually the streak of “spotless days” was recently broken when a single, tiny spot appeared and then disappeared after only a few hours. Nevertheless, September and October had the lowest sunspot counts since the last low before Solar Cycle 23:
I found this page detailing the varying predictions on Solar Cycle 24, ranging from high down to low in terms of sunspots and maximum magnetic field.
Whatever else it shows, it shows that quite a few scientists are going to be proven wrong by Solar Cycle 24.
Still absolutely no sign of Solar Cycle 24.
I wonder what we should call the next minimum in solar activity? The Hansen Minimum?
A paper published in Space Weather in 2006 used a relatively simple numerical model to add together the known solar cycles of various lengths (including the true solar cycle which is ~22 years) to produce this result:
Now from my perspective this is ho-hum in terms of solar modelling. The underlying cycles consisted of a wave groups with constant periodicity, something that really doesn’t happen in the real solar system.
In the real solar cycle, the cycle itself varies in length, shorter cycles being associated with climatic warming on Earth, longer cycles (>12 years) associated with cooling.
The conclusion of the authors is clear. Both solar cycle 24 and 25 are likely to be weak, Dalton-minimum style affairs. But will we get Dalton-minimum style climate cooling? Only time will tell…
