Graph of yearly averaged sunspot numbers 1610 to 2000 and text follows below:
The Maunder Minimum represents the coldest phase of the Little Ice Age, when solar activity was particularly low and there was an almost total absence of sunspots. In a previous blog post I presented evidence for the LIA in Australia, suggesting 17th century global cooling. There was also a slight fall in atmospheric CO2 concentrations for the period between 1550 to 1800.
Drew Shindell of NASA’s Goddard Institute for Space Studies has attempted to explain the Maunder Minimum using a climate model. According to Shindell’s results less strong ultraviolet light was emitted by the sun, which in turn caused less ozone to be formed in the stratosphere. As a result the North Atlantic Oscillation became strongly negative, causing Europe to be unusually cold.
Read the story in more detail here.
Looking at the graph of yearly averaged sunspot numbers, we can discern a rising trend in solar activity following the Maunder Minimum, peaking in the 20th century, and remaining high despite a fall after 1950. Some solar scientists, including NASA’s David Hathaway are predicting a big fall in solar activity in the not too distant future, with an uncertain impact on global temperatures. Another Maunder type minimum on the way? We may not have to wait too long to find out.
Some notes about solar activity/the solar constant:
Measurements of the Nimbus-7 and Solar Maximum Mission satellites reported temporary large decreases of the solar constant of the order of a few tenths of a percent on a time-scale from days to weeks. Investigations show that these decreases were caused by ‘active’ sunspot groups with fast development and complex structure. This connection between the solar constant variation and the appearance of the active groups seems to be clearer in the maximum of the solar activity.
The intensity of the Sun varies along with the 11-year sunspot cycle. When sunspots are numerous the solar constant is high (about 1367 W/m2); when sunspots are scarce the value is low (about 1365 W/m2). Eleven years isn’t the only “beat,” however. The solar constant can fluctuate by ~0.1% over days and weeks as sunspots grow and dissipate. The solar constant also drifts by 0.2% to 0.6% over many centuries.
Samuel Langley and Charles Greeley Abbot of the Smithsonian recorded direct measurements of the solar constant (the level of the Sun’s radiation) over several decades. They concluded that this “constant” varies by about 0.3% on the short-term scale of several days and that on the longer term, the more active Sun is brighter by about 1%. [Hufbauer, 1991]
The proxy relationships observed during solar cycle 21 and the behavior of other sun-like stars [Baliunas and Jastrow, 1990] have been used by Lean et al. [1992] to estimate the solar irradiance during the Maunder Minimum as somewhere between 0.15 and 0.35% lower than the present solar-cycle mean value. An independent estimate by Baliunas and Jastrow [1993] gave a range of 0.1 to 0.7% based purely on observations of solar-like stars, discussed by Lockwood et al. [1992]. The use of other stars to infer solar variability has been questioned by Schatten [1993], however, who has pointed out that the observed irradiance is likely to be a function of the heliographic latitude of the observer, being a minimum near the solar equatorial plane, where the Earth is located. Since other stars are observed at random latitudes relative to their spin axes, the variations observed might not be directly relevant to the local situation.
Baliunas and Jastrow [1993] conclude that a reduction in irradiance of 0.4%, in the middle of their calculated range, would be enough to explain the cold average temperatures of the Little Ice Age, as estimated by Wigley and Kelly [1990]. Hoyt and Schatten [1993] have used a variety of possible proxies for solar irradiance to estimate a value for the Maunder Minimum period that is about 5 W m-2, or about 0.36% below current values, in general agreement with other estimates. Rind and Overpeck [1993] used a general circulation model to estimate the regional temperature changes caused by a decrease of solar irradiance by 0.25%, in the middle of the range estimated by Lean et al. [1992]. They found a global average reduction of 0.45C with no clear latitudinal variation, and with the largest effects over the continental land masses.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
“Another Maunder type minimum on the way? We may not have to wait too long to find out”
The only conclusion we can draw from the graph above relative to our times is the sunspot numbers have been going up and down on a regular basis for ages.
Warm dry winds are still the order of the day.
http://www.bom.gov.au/products/IDN10035.shtml
Must be rather more complicated than sunspots, or CO2 for that matter.
Models?? Have they been validate? How can I trust them. The just goes through cycles, always has, always will. Don’t know why, it just does.
I’m not suggesting the model is right, just interesting. The best use of a model is as a diagnostic tool. And remember, the LIA actually happened – it’s not a prediction 100 years into the future. Take a look at the Shindell’s graphic and see the extent of the cooling anomoly.
And by the way, we came out of the LIA without any help from AGW.
Interesting hypothesis – fall in solar activity – UV – ozone, and a strongly negative NAO.
And herein is the problem – SJT misunderstands the approach of empirical science – wonderment at natural processes and thinking about how such processes occur.
Like a true lefty he/she looks for a hidden motive in any statement made by someone else.
Pure Marxism.
Paul,
The problem with the analysis and modelling you post here is because it is incomplete.
The underlying physical assumptions are a simple radiating sun (nuclear furnace or the standard model) into a vacuum that irradiates the earth that is also assumed to be unaffected by its physical environment, here space.
The standard model of the sun as a nucleur fusion reactor is not observed empirically. That model cannot explain the elevated temperatures of the sun’s chromosphere which are higher than its core, assumed by many, by the way, to be a neutron star, another nuclear impossibility.
Then space is not simply empty but less dense electrical plasma.
So the earth is better understood as a small electrically charged sphere floating in the electrical plasma of space. It is intimately connected to the sun and the solar system by electrical circuits. Gravity has a minor role, if any, in celestial motion.
So the Maunder Minimum (and those who have not should read the recently published book “The Sun Kings” in which the history of science, as applicable to modern astronomy, is concisely narrated.
Did you know that during 1859 the earth was hit by a CME (solar coronal mass ejection) that probably glanced past the earth. If it were a full on hit, life, as we know it, would probably be extinct.
The Maunder Minimum will start to make more sense when science starts looking at the electrical connection of the earth with the solar system, and outwards, the galaxy.
Publications by the IEEE, the largest professional scientific society we have, has a specific area of official study – the plasma universe and cosmos.
Climate science, including mainstream astronomy, know little about these natural forces. Both discplines are wedded to Victorian, gaslight, uniformitarian models of science based on gravity and a clockwork universe.
It isn’t.
Louis
the master of unintended irony.
PS
if all we relied on was empiricism, 90% of science would never have happened, and you wouldn’t be able to connect on the internet.
SJT,
You really do not understand scientific empiricism, do you. Basically it boils down to the statement “It works, or it doesn’t”.
Cell phones, microwaves, automobiles, computers are the practical results of the empirical method. An idea is formulated and tested by physical experiment.
Pseudoscience, and thus religion, pose untestable hypotheses. Climate change is one.
In any case you lefties have been completely succered in by Al Gore’s funding operation for his 2008 US presidential campaign. Paid for by the taxpayers of this planet.
Louis,
all those developments come from the work of pure science and research. The laser beam was initially an invention in search of an application, look at it now.
SJT,
And a Maser was?
Talk in riddles you do.
Being a Soft Systems advocate, I would like to know who this Maunder is (or was).
I have just answered my own question. There is much, including Wiki, on the web. A balanced essay is at http://www.stsci.edu/stsci/meetings/lisa3/beckmanj.html
Louis, who hates modelling, have you looked at the topic’s title?
Paul
I am surprised you didn’t bring the graph up to date. As of October 5th the sun has gone “all quiet”, meaning there are no sunspots anywhere on the face of the star. http://sohowww.nascom.nasa.gov/sunspots/
According to this graph – http://sidc.oma.be/html/wnosuf.html – and your graph above this is a first in any of our lifetimes – indeed it’s a first for anybody we have known living or dead.
Since October 5th, the sunspot number has remained at zero — solar cycle 24 has not yet started. The solar wind has been decreasing in speed, and this is yet another indicator of a slowing in the sun’s magnetic dynamo.
Forget the Goracle, and bundle up the kiddies.
I think we should call it the Mayeau Minimum.
What do you think?
Has a ring to it.