Solar Science Bipolar Disorder
Guest post by Steven Goddard
About once every 11 years, the sun’s magnetic poles reverse. However some high profile solar scientists reverse their own polarity more frequently.
The BBC reported Wednesday that Mike Lockwood at the University of Reading has established a statistical link between cold weather and low solar activity.
The UK and continental Europe could be gripped by more frequent cold winters in the future as a result of low solar activity, say researchers.
“By recent standards, we have just had what could be called a very cold winter and I wanted to see if this was just another coincidence or statistically robust,” said lead author Mike Lockwood, professor of space environment physics at the University of Reading, UK.
To examine whether there was a link, Professor Lockwood and his co-authors compared past levels of solar activity with the Central England Temperature (CET) record, which is the world’s longest continuous instrumental record of such data.
The researchers used the 351-year CET record because it provided data that went back to the beginning of the Maunder Minimum, a prolonged period of very low activity on the Sun that lasted about half a century.
“Frost fayres” were held on the Thames during the Maunder Minimum
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The Maunder Minimum occurred in the latter half of the 17th Century – a period when Europe experienced a series of harsh winters, which has been dubbed by some as the Little Ice Age. Following this, there was a gradual increase in solar activity that lasted 300 years.
Professor Lockwood explained that studies of activity on the Sun, which provides data stretching back over 9,000 years, showed that it tended to “ramp up quite slowly over about a 300-year period, then drop quite quickly over about a 100-year period”.
He said the present decline started in 1985 and was currently about “half way back to a Maunder Minimum condition”. More at the BBC
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His study was basically a rehash of what many others have done previously over the past few centuries, but he has the BBC’s ear – because in 2007 he prominently claimed just the opposite.
No Sun link’ to climate change
Tuesday, 10 July 2007
“This should settle the debate,” said Mike Lockwood
Similarly, in 2006 David Hathaway at NASA reported that the Sun’s conveyor belt had “slowed to a record low.”
May 10, 2006: The Sun’s Great Conveyor Belt has slowed to a record-low crawl, according to research by NASA solar physicist David Hathaway. “It’s off the bottom of the charts,” he says. “This has important repercussions for future solar activity.”
Then on March 12, 2010 he reported the exact opposite:
March 12, 2010: In today’s issue of Science, NASA solar physicist David Hathaway reports that the top of the sun’s Great Conveyor Belt has been running at record-high speeds for the past five years.
In 1810, the great English astronomer William Herschel established a link between sunspot activity and the price of grain in Europe – a proxy for climate. As far as we know, he never reversed polarity on that belief. Modern solar science is just coming around to what Herschel hypothesized 200 years ago.
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UPDATE: Full Lockwood et al paper at Environmental Research Letters here
Abstract. Solar activity during the current sunspot minimum has fallen to levels unknown since the start of the 20th century. The Maunder minimum (about 1650–1700) was a prolonged episode of low solar activity which coincided with more severe winters in the United Kingdom and continental Europe. Motivated by recent relatively cold winters in the UK, we investigate the possible connection with solar activity. We identify regionally anomalous cold winters by detrending the Central England temperature (CET) record using reconstructions of the northern hemisphere mean temperature. We show that cold winter excursions from the hemispheric trend occur more commonly in the UK during low solar activity, consistent with the solar influence on the occurrence of persistent blocking events in the eastern Atlantic. We stress that this is a regional and seasonal effect relating to European winters and not a global effect. Average solar activity has declined rapidly since 1985 and cosmogenic isotopes suggest an 8% chance of a return to Maunder minimum conditions within the next 50 years (Lockwood 2010 Proc. R. Soc. A 466 303–29): the results presented here indicate that, despite hemispheric warming, the UK and Europe could experience more cold winters than during recent decades.
Figure 2 from the paper:
- Figure 2. Variations since the mid-17th century of the following. (a) The mean northern hemisphere temperature anomaly, ΔTN: black shows the HadCRUT3v compilation of observations [17, mauve shows the median of an ensemble of 11 reconstructions (individually intercalibrated with the HadCRUT3v NH data over the interval 1850–1950) based on tree ring and other proxy data [18–23]. The decile range is given by the area shaded grey (between upper and lower decile values of ΔTU and ΔTL). (b) Average winter Central England Temperatures (CET) [5, 6] for December, January and February, TDJF. (c) The open solar flux, FS, corrected for longitudinal solar wind structure: dots are annual means of interplanetary satellite data; the black line after 1905 is derived from ground-based geomagnetic data [1]; and the mauve line is a model based on observed sunspot numbers [14]. Both curves show 1 year means. (d) Detrended winter CET, δTDJF, obtained by subtracting the best-fit variation of ΔTN, derived using the regressions shown in figure 3(b): the width of the line shows the difference resulting from the use of ΔTN = ΔTU and ΔTN = ΔTL prior to 1850. In all panels, dots are for years with δTDJF < 1 °C (the dashed horizontal line in (d)), colour-coded by year using the scale in figure 3(a). Data for the winter 2009/10 are provisional.”]
Leif Svalgaard (13:00:11) :
Here is what I get:
http://www.leif.org/research/Nutation-in-Obliquity.png and
http://www.leif.org/research/Nutation-in-Obliquity-and-Longitude.png
http://www.leif.org/research/Nutation-1920-1960.png
The small wiggles are mostly due to a semiannual variation.
The last plot is the total nutation during 1920-1960, graphed from its two components.
Leif Svalgaard (13:44:25) “I don’t know where you get the graph from.”
I’ve isolated the decadal-timescale component of observational records of nutation in obliquity obtained here:
http://hpiers.obspm.fr/eop-pc/
Thanks for the graphs which you have posted.
If you can point to materials that will clarify the difference between the curves which you have plotted and the curve which I have plotted, that will be greatly appreciated. I need to learn the proper terminology to describe the curve which I have isolated from the IERS observational data.
Paul Vaughan (17:03:58) :
I’ve isolated the decadal-timescale component of observational records of nutation in obliquity obtained here:
http://hpiers.obspm.fr/eop-pc/
The polar wander is not the nutation of the obliquity. You conflate the two. Nutation is where the axis of rotation moves, i.e. the North Pole points toward a different star. Polar wander is where a planet undergoes a solid-body rotation with respect to its spin axis, like if you try to spin a ball of butter about a fixed axis [e.g. a pin stuck through it]; the butter ball may slide off to the side, especially if it not perfectly round. It is because the Earth is really triaxial and is not perfectly rigid.
I just found this link to Lockwood’s paper if anyone is interested:
http://iopscience.iop.org/1748-9326/5/2/024001/pdf/1748-9326_5_2_024001.pdf
Oh, by the way, the sun is blank today, no sunspots! I think the sucker is broke, probably needs new (conveyor) belts, just like my car!
Leif Svalgaard (14:52:27) :
2) something else is changing the climate, so that the impact of the same Sun might be different
I’ll offer a 3rd option based on your 2nd one:
something else is changing the Sun AND the climate, which keeps both the Sun and the Earth’s internal mechanisms intact, but capable of being affected down the chain of command.
When Earth was going through it’s latest warming period, so were other Planets. That’s an unaccounted for effect. It is possible that the entire Solar System was affected by external forces.
And further, it is possible that only the Planets observed to warm were affected, but the Sun is only cosmetically affected.
So, does NASA have any new info on the Planets they observed to be warming, as in they are now cooling?
Leif Svalgaard (20:07:23) “Nutation is where the axis of rotation moves, i.e. the North Pole points toward a different star. Polar wander is where a planet undergoes a solid-body rotation with respect to its spin axis, like if you try to spin a ball of butter about a fixed axis [e.g. a pin stuck through it]; the butter ball may slide off to the side, especially if it not perfectly round. It is because the Earth is really triaxial and is not perfectly rigid.”
I already understood this.
Leif Svalgaard (20:07:23) “The polar wander is not the nutation of the obliquity. You conflate the two.”
IERS calls the variable nutation in obliquity. They give 5 output variables: LOD, polar motion x, polar motion y, nutation in obliquity, & nutation in longitude (along with error estimates for each).
rbateman (23:44:44) :
When Earth was going through it’s latest warming period, so were other Planets.
Links, please.
The outer planets move so slowly in their orbits that what we see may just b seasonal changes. The microwave temperature of Uranus has declined from ~255 +/- 10 K (circa 1984-86) to ~200 +/- 8 K in 2002. http://aas.org/archives/BAAS/v34n3/dps2002/279.htm
“Mars’ atmosphere now seems to be both colder and dryer than measured by the Viking landers [1976]”
http://nineplanets.org/mars.html
Paul Vaughan (03:04:49) :
They give 5 output variables: LOD, polar motion x, polar motion y, nutation in obliquity, & nutation in longitude (along with error estimates for each).
I don’t think so. They may give the tiny difference [dEps] between the calculated mean nutation and the actually observed one; like climate people talking about the ‘anomaly’, although this is not standard terminology in EOP. The latter being influenced by non-astronomical things, like the climate/weather and volcanism. One of your [perennial] problems is that your never show the actual units of what you graph, but normalize it somehow. This is bad practice, as it makes the ‘smell test’ harder.
Leif:
Two of the links are rather old for the Global Warming on other worlds, which is why I am interested in any recent follow-ups/corroborating observations.
http://web.mit.edu/newsoffice/2002/pluto.html
http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html
http://web.mit.edu/newsoffice/1998/triton.html
rbateman (10:02:35) :
http://web.mit.edu/newsoffice/2002/pluto.html
Pluto’s orbit is very eccentric and the increase is likely simply that Pluto was getting closer to the Sun [as the paper mentions]. Since then, Pluto is receding from the Sun, so the ‘warming’ should subside [after the inevitable lag that people often invoke to explain away discrepancies].
http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html
talks about ‘three summers in a row’. Here is a reasoned paper on Mars:
http://www.gps.caltech.edu/uploads/File/People/mir/Szwast_JGR2005JE002485.pdf
“Finally, we show that the apparent long-term darkening of the southern mid and high latitudes between the Viking and MGS eras is largely a consequence of the timing of image acquisition relative to global dust storms and surface dust ‘‘cleaning’’ by the seasonal ice cap; it does not represent a steady decadal-scale, secular change.”
http://web.mit.edu/newsoffice/1998/triton.html
From the clip: “The moon is approaching an extreme southern summer, a season that occurs every few hundred years.”
Yeah, summer is a clear indication of global warming. Works here on Earth too. It is indeed warmer during the summer.
It is amazing to what lengths people will go to maintain their myths, rather than try to read and understand what they cite.
Leif Svalgaard (05:30:23) “They may give the tiny difference [dEps] between the calculated mean nutation and the actually observed one; like climate people talking about the ‘anomaly’, although this is not standard terminology in EOP. The latter being influenced by non-astronomical things, like the climate/weather and volcanism.”
These notes are very helpful, particularly since I have no local access to people with expertise in EOP.
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Leif Svalgaard (05:30:23) “One of your [perennial] problems is that your never show the actual units of what you graph, but normalize it somehow. This is bad practice, as it makes the ’smell test’ harder.”
As discussed previously, this is a matter of competing paradigms about what is good practice. From a statistical point of view, it is drilled into students heads that rescaling does NOT affect measures like correlation, wavelet transforms, etc. From a data visualization perspective, normalization optimizes human perception of pattern.
I welcome your reiteration of this message about how to cater to a physics audience.
I get the point:
Physicists have different priorities and may be suspicious of claims based on graphical presentations that are conforming to paradigms other than those which are conventional in mainstream physics. (And this statement extends beyond physics.)
I thank you for reinforcing this point, particularly as I have no local access to physicists who will answer questions about such things. (They prioritize study of other things (e.g. dark matter) and have maintained a policy of not hiring people with interest in celestial mechanics for decades, something I am told may be about to change, however, which is welcome news from my perspective).
Leif:
I’d prefer to use a bit of math. Since I am not so good at it, I have posted below the data for Neptune from The Sky (Software Bisque) from 3 years.
April 20, 2010
Neptune
Phase: 99.978%, Apparent magnitude: 7.94
Heliocentric ecliptical:
l: 326°33’30.4″ b: -00°26’52.1″ r: 30.021379
Geometric geocentric ecliptical:
l: +328°15’12” b: -00°26’28” r: 30.473975
Mean geometric ecliptical:
l: +328°15’09” b: -00°26’28” r: 30.473963
Triton : 30.019939055501 r in AU (JPL HORIZONS)
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1998
Phase: 99.972%, Apparent magnitude: 7.92
Heliocentric ecliptical:
l: 300°12’14.5″ b: +00°21’16.8″ r: 30.141702
Geometric geocentric ecliptical:
l: +302°06’57” b: +00°21’16” r: 30.152565
Mean geometric ecliptical:
l: +302°06’53” b: +00°21’16” r: 30.152553
Triton : 30.140919921374 r in AU (JPL HORIZONS)
—————————
1989
Phase: 99.975%, Apparent magnitude: 7.91
Heliocentric ecliptical:
l: 280°33’43.1″ b: +00°54’55.1″ r: 30.216640
Geometric geocentric ecliptical:
l: +282°22’09” b: +00°55’32” r: 29.885389
Mean geometric ecliptical:
l: +282°22’06” b: +00°55’32” r: 29.885376
Trtion: 30.216593378272 in AU (JPL HORIZONS)
I would be inclined to think that the Heliocentric r is what we want, but I included the geocentrics as well. I used JPL’s Horizon to compute Triton’s Heliocentric r in comparison to Neptune, since The Sky Planetarium program does not give me Triton.
What I don’t know how to arrive at is the difference in degrees F that should result from watts/meters^2 out to Neptune/Triton for the 3 years.
Neptune/Triton is moving away from the Sun in elliptical orbit, so either the measurements are in error, the uncertainties too large, or there is more to be determined here.
Can you tell me what values should I plug into 1=S/4*pi*r^2 and what representation of the equation should give the needed answer.
Leif:
Oops, I should have quoted this fromt the 1998 MIT triton link:
“At least since 1989, Triton has been undergoing a period of global warming. Percentage-wise, it’s a very large increase,” said Elliot, professor of Earth, Atmospheric and Planetary Sciences and director of the Wallace Astrophysical Observatory. The 5 percent increase on the absolute temperature scale from about minus-392 degrees Fahrenheit to about minus-389 degrees Fahrenheit would be like the Earth experiencing a jump of about 22 degrees Fahrenheit. ”
The -392F and -389F need to go into 1=S/4*pi*r^2 formula.
Paul Vaughan (12:41:33) :
From a statistical point of view, it is drilled into students heads that rescaling does NOT affect measures like correlation, wavelet transforms, etc.
If it makes no difference, then why rescale in the first place? It adds another step, and makes the result more difficult to visualize. Physics is a very intuitive science. You usually intuit the result, then dress it up with math.
rbateman (13:15:37) :
April 20, 2010
Phase: 99.978%, Apparent magnitude: 7.94
Geometric geocentric ecliptical:
l: +328°15′12″ b: -00°26′28″ r: 30.473975
1998
Phase: 99.972%, Apparent magnitude: 7.92
Geometric geocentric ecliptical:
l: +302°06′57″ b: +00°21′16″ r: 30.152565
1989
Phase: 99.975%, Apparent magnitude: 7.91
Geometric geocentric ecliptical:
l: +282°22′09″ b: +00°55′32″ r: 29.885389
The apparent magnitude [seen from Earth] is increasing [getting dimmer] as it should.
But more importantly “the moon is approaching an unusually warm summer season that only happens once every few hundred years. Elliot and his colleagues believe that Triton’s warming trend could be driven by seasonal changes in the absorption of solar energy by its polar ice caps.”. So, no solar activity link.
Leif Svalgaard (14:32:37) “If it makes no difference, then why rescale in the first place? It adds another step, and makes the result more difficult to visualize. Physics is a very intuitive science. You usually intuit the result, then dress it up with math.”
You are a physicist. My academic background has 7 branches. One of my roles has been teaching Stat 101 online. Another has been learning data visualization techniques based on psychological research. When attempting to make it intuitive for math-anxious arts students to understand via the online medium concepts like correlation, things go MUCH more smoothly if the teacher supplies helpful visuals. (The cost of not doing it right is a murderous onslaught of phenomenally time-consuming questions.)
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I thank you again for your very helpful comment on ‘dEps’.
Cheers.
Paul Vaughan (16:12:33) :
When attempting to make it intuitive for math-anxious arts students to understand via the online medium concepts like correlation, things go MUCH more smoothly if the teacher supplies helpful visuals.
And that means using meaningful units that the students can understand and relate, feet, Fahrenheit, AUs, etc, rather than e.g. standard deviations [often used for normalization].
Leif Svalgaard (17:11:56) “And that means using meaningful units that the students can understand and relate, feet, Fahrenheit, AUs, etc, rather than e.g. standard deviations [often used for normalization].”
You are either missing or ignoring the point.
A REQUIRED learning outcome of Intro Stats is that students understand that THE UNITS ARE IRRELEVANT STATISTICALLY (and when I say REQUIRED, bear in mind that the learning outcomes are not set by lowly instructors, nor are they even necessarily set by department chairs — they are generally set by multi-institution committees to ensure credit-transfer eligibility).
Practical significance vs. statistical significance is another learning outcome. THAT is where your point fits in (and THAT is best left to practitioners in other fields — it is NOT AT ALL REASONABLE to expect statisticians to be well-versed in what is PRACTICALLY significant IN EVERY SINGLE FIELD — the Stat’s teacher’s job is to teach STATISTICAL concepts — of course the students take other courses as part of a well-rounded program, so they are not limited to acquiring only a statistical perspective – they’ll run into important lessons from folks like you IN OTHER COURSES).
You can afford to show a little respect to other fields. When I was in the Statistics Department I never heard my superiors barking at the physics profs about how to teach Physics 101.
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Thanks for the notes on ‘dEps’. That was constructive.
Leif Svalgaard (14:32:37)
What I really wanted to know is how to work the W/m^2 by the inverse square law correctly and run the numbers, but not specifically for the solar activity link. The temperature of other planets at distance from the Sun would be a refreshing break from the fixation on Earth and it’s trace C02 fuss.
Paul Vaughan (18:29:34) :
A REQUIRED learning outcome of Intro Stats is that students understand that THE UNITS ARE IRRELEVANT STATISTICALLY
How do they understand that other that you simply TELL them that up front. This should not be hard to understand: X = a X’ + b.
But there are situations where the unit is not constant, e.g. the Richter scale, the Kp index, the magnitude of stars, and many others. These indices you cannot perform the usual statistical calculations on, like calculating the moments. This would be a valuable lesson that only for variables for which the units do not matter, do the usual statistical procedures make sense at all, making the whole thing a tautology.
If statistics is to have any value, it must be used in real-world situations, where input values have units, and where results should be presented in those same units to make sense to the non-statisticians that are the raison d’etre for using statistics at all. You show respects for your ‘users’ rather than they show respect for your field.
These comments are as constructive that I can make them.
rbateman (18:34:59) :
What I really wanted to know is how to work the W/m^2 by the inverse square law correctly and run the numbers
The temperature, T, in Kelvin is given by T = Ts * SQRT(Rs/(2*As)), where Ts is the temperature of the Sun = 5780K, Rs the radius of the Sun = 696,000 km, As the distance to the Sun which for the Earth is 149,600,000 km. Doing the numbers for the Earth we get Te = T = 279K. For a planet at distance Ap [in AU], the formula is simply Tp = Te/SQRT(Ap). So for Neptune where An = 30 AU, Tn becomes 279*SQRT(1/30) = 50K.
The above assumes that the planets are black bodies, while in reality they reflect a certain fraction of the energy from the Sun and thus would be at a lower temperature. On the other hand, there is a ‘greenhouse’ effect that raises the temperature above that of a black body, depending on the amount [pressure] of greenhouse gases. The net effect is that the two opposing effects often nearly cancel, so the formula given is not too bad. An exception is Venus with its extremely dense atmosphere.
Leif Svalgaard (19:34:02) : correction
to rbateman (18:34:59) :
For a planet at distance Ap [in AU], the formula is simply Tp = Te*SQRT(1/Ap). So for Neptune where An = 30 AU, Tn becomes 279*SQRT(1/30) = 50K.
For a gas planet, one might debate what the temperature means, where to measure it, etc. The temperates calculated here are ‘effective temperatures’, that is, the temperature at which the planet radiates away what it gets from the Sun.
Leif Svalgaard (20:21:08) :
As long as one does the same type of measurement from a far enough distance to get a mean temp. Measuring Earth is a problem becasue we are on Earth. It would be helpful to measure Earth plus the other available planets from Mars orbit, while measuring the planets from Earth orbit.
Re: Leif Svalgaard (19:34:02)
Leif, I appreciate your comments. The ladder of powers is addressed but the course is moving too fast for most students to appreciate it deeply. Stat 101 is a jam-packed course with a limited scope. Underlings (even ones who score 70% “excellent” in ratings from students) who are too pushy with an education-reform agenda may quickly lose their contracts or get reassigned to less desirable duties. (At first I considered reassignment to climate research a demotion. Later it became evident that while the pay was lower, the freedoms were much higher.)
On a lighter note, your pal Piers Corbyn has released a new bedtime story you might want to check out:
http://fintandunne.com/audio/BeautifulTruth-10-03-31.mp3
Sweet dreams.
Paul Vaughan (00:04:52) :
Piers is easy listening. I’d welcome him doing a guest post on a general forecast for summer oh-10.
rbateman (12:38:32) “Piers is easy listening.”
He’s a talented communicator – colorfully packs a lot of details into short soundbites.