Is the Sun driven by two dynamos, each running on slightly different 11 year cycles?
Many people are talking about a new forecast of a mini-ice age (which seems to be an increasingly popular thing to predict.) This one comes from a paper published last year but presented at the Royal Astronomical Society last week. Shepard, Zharkov and Zharkova may have gotten us a step closer to understanding why the solar cycle varies in length from 8 to 14 years. Since the level of solar activity correlates with both the the length of the current solar cycle and the surface temperatures on Earth one solar cycle later (the notch-delay theory, and see the work of David Archibald), it may make it possible to predict the climate decades in advance. (With the caveat that this new study is still a model, correlation is not causation, etc.)
One of the better descriptions comes from Astronomy Now.
The Sun, like all stars, is a large nuclear fusion reactor that generates powerful magnetic fields, similar to a dynamo. The model developed by Zharkova’s team suggests there are two dynamos at work in the Sun; one close to the surface and one deep [...]
Sometime around 2007 or 2008 the sun’s magnetic field should’ve become more active again as part of the cycle it had been roughly following for at least 80 years. Instead it fell. The current solar cycle is not like all the other ones…
David Archibald has drawn my attention to the Ap Index and just how remarkably different the current solar cycle is. He also points out that solar physicists were cranking out predictions about this cycle during the last cycle, but now hardly anyone wants to stake a claim on what the sun will do in the next cycle.
Ap Index 1932 – 2014 | Click to enlarge
From David Archibald
The Ap Index is a measure of geomagnetic activity from eight stations around the planet and reflects disturbances in the horizontal component of the Earth’s magnetic field. Activity for the current solar cycle has peaked at about the floor activity for the prior solar cycles back to early 1930s.
David Archibald writes that solar physicists have hit a quiet cycle too.
“The solar physics community has gone very quiet. There are almost no predictions of Solar Cycle 25 maximum.
David Archibald points at a very interesting paper that suggests that children conceived during solar activity peaks were less likely to survive and had a whopping 5 year deduction from their lifespan. But don’t panic if you were a peak baby, the affected people were born to poorer women in Scandinavia in the 18th and 19th century. Mortality was 8% in the first year. One in twelve babies didn’t make it. Things were different then. Richer women were somehow able to compensate, or repair the damage. The authors seem fairly sure it has something to do with UV, but I’m not convinced. Solar effects include magnetic effects, solar wind, neutron bombardment, and cosmic rays. There are plenty of things to choose from. Lots more papers to come on this.
Marvel that the sun might influence our lifespan and fertility, but not “do much” to the climate. ;- )
There is much to discuss in comments — many of us wondered if there is a dietary connection, but this effect does not seem to be due to famine, or less food (wheat was cheaper at solar maxes).
Guest Post by David Archibald
Solar Activity At Birth
It is now [...]
This new paper by Adophi et al uses beryllium, oxygen and carbon isotopes from Greenland ice cores right back as far as the depth of the last ice age, 22,500 years ago, and finds there is a link between solar activity and the climate. It follows these proxies of temperature and solar activity as the planet warmed to the start of the Holocene 10,000 years ago.
It is gaining attention in The Daily Mail, with the headline:
Is the SUN driving climate change? Solar activity – ‘and not just humans’ – could be increasing global warming, study claims
During the last glacial maximum, Sweden was covered in a thick ice sheet that stretched all the way down to northern Germany and sea levels were more than 330ft (100m) lower than they are today, because the water was frozen in the extensive ice caps.
‘The study shows an unexpected link between solar activity and climate change,’ Dr Muscheler said in a press release.
‘It shows both that changes in solar activity are nothing new and that solar activity influences the climate, especially on a regional level.
Dr Joanna Haigh, Professor [...]
Could this be why climate models do rainfall with all the competence of tea-leaf-reading? Tiwari et al report that as much as 47% of the recharge rates of ground water in China are controlled by the sun. Apparently climate models miss the minor factor of the major cycles.
Try this radical idea on: imagine a world where climate models worked. Not only could the BoM warn people that there would be a drought coming, they could name the region, and the years.
Tiwari et al:
Here for the purpose of comparison of long term ground water recharge rates with long term solar activity, we used the 10-year average sunspot time series, for the period 1300 to 1905 AD, published by Solanki et al., . Also the additional average annual sunspot number time series (1700 to 2000 AD) is used from data source Solar Influences Data Analysis Centre. In addition to decadal data annual sunspot number data from 1700 to 2000 AD downloaded from Solar Influences Data Analysis Centre is used in the present study. The cross-correlation coefficient (+0.63) between the groundwater recharge rate time series and decadal sunspot number [Solanki et al., 2004] shows that there is statistically significant solar [...]
UPDATED AGAIN #4 — Now with Vukcevics Hale cycle graph of Echuca. and #3 David Archibalds suggestion of the Hale Cycle at work. #2 with Willis Eschenbach’s graph and my thoughts, (see below)
Ian Bryce sent me a striking graph (or two). Looking at the original raw data from Echuca Victoria shows a dramatic cooling trend of nearly half a degree since 1900, and rather than being a siting anomaly, it’s repeated in two towns about 100km away.
Curiously he also finds peaks in the maximums at Echuca that look for all the world like they match the solar cycle. Is it a fluke, or could it be real? If it’s real, what conditions make the solar sun-spot cycle so apparent in Echuca — where its maximum temperatures seemingly peak with each second solar cycle. Can anyone find this signal in other places? — Jo
The area is inland Northern Victoria
Has there been Global Warming or Global Cooling in Echuca
Guest post: Ian Bryce
I have spent about 37 years working with processing tomatoes in the Goulburn Valley in Australia, and the last 25 years or so, with research into growing and processing canning tomatoes. Since 1984, our [...]
David Archibald, polymath, makes a bold prediction that temperatures are about to dive sharply (in the decadal sense). He took the forgotten correlation that as solar cycles lengthen and weaken, the world gets cooler. He refined it into a predictive tool, tested it and published in 2007. His paper has been expanded on recently by Prof Solheim in Norway, who predicts a 1.5°C drop in Central Norway over the next ten years.
Our knowledge of they solar dynamo is improving, and David adds the predicted solar activity ’til 2040 to the analysis. Normal solar cycles are 11 years long, but the current one (cycle 24) is shaping up to be 17 years (unusually long), and using historical data from the US, David predicts a 2.1°C decline over Solar Cycle 24 followed by a further 2.8°C over Solar Cycle 25. That adds up to a whopping 4.9°C fall in temperate latitudes over the next 20 years. We can only hope he’s wrong. As David says ” The center of the Corn Belt, now in Iowa, will move south to Kansas.”
He also predicts continuing drought in Africa for another 14 years, with droughts likely in South America too.
If he’s right, [...]
Ominously, the embryonic markers of solar cycle 25 are three years late and are nowhere to be seen. Scientists are asking if this could be the start of another Maunder-type Minimum. (The bummer with that, being that during those 70 quiet years the world slipped into the Little Ice Age; animals froze in barns, people starved, disease raged… see The brutal cold of the Maunder Minimum and the Great Irish Frost for some light entertainment.)
If it were going to happen, we ought to start preparing now, right? You know, take precautions, “buy insurance”, figure out if CO2 actually does any useful warming (and if so, pump more of it into our atmosphere). You know it makes sense…
Seriously, if the cold is coming, we really ought to pay attention. — Jo
From the press release today (June 14):
Major Drop in Solar Activity Predicted
“This is highly unusual and unexpected,” Dr. Frank Hill, associate director of the NSO’s Solar Synoptic Network, said of the results. “But the fact that three completely different views of the Sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation.”
Normally cycles [...]
TODAY June 7th 2011: Phenomenal eruption on the sun (see the bottom of the post for more info).
Apparently previous studies of the sun-climate connection looked at the equatorial polar magnetic field which produces sun spots, but they did not consider the polar magnetic component of the solar dynamo. The polar fields are less strong than the equatorial fields, but it is claimed that the total magnetic fluxes of both fields are comparable. With proxy data they derive an empirical relation between tropospherical temperatures and solar equatorial and polar magnetic fields. The polar field could contribute about 30% as much as the equatorial field.
The paper, published in the Journal of Atmospheric and Solar-Terrestrial Physics focused on the period 1844-1960 (but extended at least one graph back to 1600) and finds our current warming period is not that different from earlier episodes and that the increase in solar activity in the last 400 years explains the warming, without any need to invoke a man-made enhanced greenhouse hypothesis.
Who would have thought that if you knew the air pressure in Darwin and Tahiti in June, you could figure out that the start of 2011 might be a Stalingrad Winter up North and a cooler wetter summer down south (Not that people in Sydney feel all that cool right now). But the air pressure ratios are reported as the SOI (Southern Oscillation Index) and it’s the handiest thing if you like predicting global temperatures 7 months ahead. Look at that correlation.
Since June last year Bryan Leyland has been using the simple connection described by Carter, De Freitas, and McLean in 2009 to predict up and coming temperatures.
So far, for what it’s worth, he’s right on track.
Such is the power of the stored pool of cold that is the bottom three-quarters of the Pacific Ocean. And when you look at how vast the Southern Pacific ocean is, is it any wonder it has such an influence? All that heat capacity…
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