In Surveys in Geophysics
Solar Forcing of Climate
C. de Jager
Received: 4 November 2011/Accepted: 16 April 2012
(c)The Author(s) 2012.
This article is published with open access at Springerlink.com here.
Abstract
Solar activity is evident both in the equatorial activity centres and in the polar magnetic field variations. The total solar irradiance variation is due to the former component. During the extraordinarily long minimum of activity between sunspot cycles 23 and 24, the variations related to the equatorial field components reached their minimum values in the first half of 2008, while those related to the polar field variations had their extreme values rather at the end of 2009 and the first half of 2010. The explanation of this delay is another challenge for dynamo theories. The role of the open solar flux has so far been grossly underestimated in discussions of Sun-climate relations. The gradual increase in the average terrestrial ground temperature since 1610 is related both to the equatorial
and polar field variations. The main component (0.077 K/century) is due to the variation of the total solar irradiance. The second component (0.040 K/century) waits for an explanation. The smoothed residual increase, presumably antropogenic, obtained after subtraction of the known components from the total increase was 0.31 K in 1999.
The reference to differential (and time lagged) responses to solar variations between equator and pole is interesting to me.
I have been suggesting for some time that latitudinal climate zone shifting requires a change in the slope of tropopause heights between equator and pole.
This would fit with my proposition that solar variations alter the vertical temperature profile of the atmosphere differentially at different heights and at different latitudes.
Stephen, this article about possible reasons for the decline of pan evaporation over the last 50 yrs might interest you http://biology.anu.edu.au/CMS/FileUploads/file/Farquhar/272RodericketalPanreviewIIGeogCompass2009_000.pdf might interest you. They suggest three factors a) increase in humidity, decline in solar radiation (due to clouds?), and decrease in wind velocity. I have not seen the third factor mentioned before although they give some reference papers. As I recall there is also evidence that landfall cyclones, hurricanes and tornadoes have been decreasing which could fit with decreasing wind.
Just goes to show that climate is complex.
Thanks cementafriend.
The article suggests reduced windspeed as a potential factor.
When the sun is more active, cloudiness decreases and the subtropical high pressure cells both expand and push poleward.
I would expect less windiness from reduced air mass mixing when those high pressure cells are larger.
The mid latitude depression tracks get restricted to a narrower, more zonal and poleward band for less global cloudiness and windiness overall.
I would be interested in an update as to whether pan evaporation rates have stabilised since around 2000 which is when I first noticed the climate changes going into reverse.
I don’t think that anyone knows the total solar forcing.
The most recent reconstruction of TSI based by Wang, Lean, and Sheeley (The Astrophysical Journal, 625:522-538, 2005 May 20) is based on a flux transport model to simulate the long-term evolution of the closed magnetic flux that generates bright faculae, i.e. it is based on the solar magnetic activity; it shows up-trend since 1700.
Dr. Svalgaard offers an alternative reconstruction TSI with near zero trend since 1700.
Graphic comparison (Leif 2007 vs. Wang 2005) is shown here:
http://www.leif.org/research/TSI-LEIF.pdf
In my research I found that changes in the Antarctic’s magnetic field (on bi-decadal scale) are closely synchronized with the TSI, i.e. the solar closed magnetic flux (Wang 2005), but in the percentage terms, changes in the Antarctic’s MF are 40 times greater than those in the corresponding TSI.
Comparing the Svalgaard’s TSI data with the Antarctic’s MF (after de-trending) for period 1900 to date, shows stronger correlation than the Wang et al (2005), while prior to 1900 the correlation is about equal.
http://www.vukcevic.talktalk.net/SSN-dBzA1.htm
(for the Svalgaard’s TSI see the last graph)
Some interesting bits of the paper:
“The main component (0.077 K/century) is due to the variation of the total solar irradiance. The second component (0.040 K/century) waits for an explanation. The smoothed residual increase, presumably antropogenic (sic), obtained after subtraction of the known components from the total increase was 0.31 K in 1999.”
“Essentially, the differences between UV and visual spectral irradiance would be important for climate modelling”
“Over the past grand maximum of solar
activity, the OSF shows a steady increase with time and, while the sunspot data reached
their largest values during the extreme maximum of 1957–1958, the OSF had its maximum
values only after 1980 according to Lockwood”
“UV radiation is absorbed in stratospheric
layers. The precise height and degree of absorption depend both on the wavelength and on
the chemistry of the stratosphere. The resulting terrestrial surface temperature variation
depends on the degree of coupling between the stratosphere and the lower layers. The
forcing is not yet well defined, and the physical explanation of the solar effects is still beset
with uncertainty.”
“the average temperature increase over the period 1610–1970
(hence before the period of significant antropogenic warming) can be split in three com-
ponents (cf. de Jager et al. 2010). Correlated with the equatorial field is an average increase
of 0.077 K/century; the polar field component is 0.040 K/century, and a remaining part of
0.051 K/century is not of solar origin.”
I wonder how de Jager squares his statement that 0.31K is “presumably antropogenic”(sic)
With
” The
forcing is not yet well defined, and the physical explanation of the solar effects is still beset
with uncertainty.”
Vuk: ” Svalgaard’s TSI see the last graph”
Heh. Keep going Leif, almost flat now. Just another few passes with the iron on that data.
Why don’t we see a very large variation in TSI (6.8% i think) that occurs yearly due to the Earth’s eliptical orbit in TSI plots? What about the nutation in Earth’s axis (period of 18.6 years)?
@Vukcevic: A big achievement indeed, which relates to the Sun´s EM field. It results obvious how energy works everywhere: electro and magnetics. Polarity, the generation of order and symmetry…. The new generations will accept it and study it, as the cultures of old did, it is everywhere, but what else can we do for making the blind to see?.
Fellows: the numbers confuse me.
….the average temperature increase over the period 1610–1970
(hence before the period of significant antropogenic warming) can be split in three components (cf. de Jager et al. 2010). Correlated with the equatorial field is an average increase
of 0.077 K/century; the polar field component is 0.040 K/century, and a remaining part of
0.051 K/century is not of solar origin. The first is explained by the variation of the TSI
provided one includes a positive water vapour feedback of a factor 2. The feedback effect
was discussed by Rozanov, who showed that there is a fair amount of coupling between
stratospheric warming and the resulting tropospheric effects. It was, though, not quantified.
The second component has not yet found a physical explanation, while the third must be
due to atmospheric effects. After having subtracted the above-mentioned components from
the recent average surface temperature values, a smoothed residual for 1999 was left of
0.31 K.
Q: 0.168K/century is the total average from 1610 -1970, 360 years, or 0.605K. The missing 0.31K equals an error of attribution of 0.086K/century, or a 37% error of each three elements. What do you think an error level is likely to be for the combined three?
Q: The first: .077K/century is described as TSI WITH AN ASSUMED WATER VAPOUR FEEDBACK OF 2.0X, or 0.277K. If the feedback is actually 1.0, where would the additional temperature rise be located in his analysis?
Q: The second and third, totaling 0.121K/century, are of unknown cause (0.040K/century) or origin and cause (“must be due to an atmospheric effect”, hardly being definitive) (0.051K/century) .
I can accept attribution without cause, but “an atmospheric effect” seems to have both attribution AND cause left to be determined.
Q: The entire temperature breakdown is based on 2009 being 0.605K warmer than (I think his reference point being) 1610. I’ve been looking into temperatures in the period of champagne development, 1570 – 1650, and find the difference to be considerable within France. How solid is this reference temperature?
0.31K: if part is attributable to an inappropriate reference temperature, part is attributable to the unknown “atmospheric” effect, and error bars are taken into account, how much is PROBABLY left over for attribution to other causes, oceanic or AGW?
I did read the paper, but I find the fineness of mathematical explanations to be close to what I felt was the believable limits of data collection. In fundamental science the anomaly is significant relative to the measuring precision. Once something is really well understood, several significant figures mean something; I’m not sure that climate science is there.
Hasn’t Hansen shown us with GISTemp that the “errors” are 2X the initial signal, in that fixing the errors gives you 3X the anomaly you would have had otherwise? And that is only for the past 130 years?
Edim: “Why don’t we see a very large variation in TSI (6.8% i think) that occurs yearly due to the Earth’s eliptical orbit in TSI plots?”
Because the plots are corrected to represent total solar irradiance at Earth’s average orbital distance.
Tallbloke, thanks. I supposed that. Are there uncorrected plots?
Edim: not so far as I know, but it wouldn’t be difficult to approximate by adding an annual sinusoidal variation of ~7% to the TSI data.
adolfogiurfa says: May 13, 2012 at 6:35 pm
……………
Hi Adolfo
Question is why the Antarctic’s magnetic changes are such a large percentage in comparison to the TSI?
- TSI changes are only a minor factor in the solar activity in comparison with the electro-magnetic factors.
- There is a strong possibility that these changes are electrically induced when the Earth transverses currents of about billion Amps in a magnetic cloud with radius many Earth’s radia, so the Earth gets only a fraction, but it is focused at poles. Magnetic cloud is started by a CME in proces initiating geomagnetic storms hitting the Earth
These currents are often much larger
You can see here that a single hit preceding Japan’s earthquake shifted temporarily the vertical component Bz about 0.8%, and horizontal about 4%.
Although most of the change is only temporary, small fraction remains and the change accumulates with the time, as you can see from these daily records:
http://www.vukcevic.talktalk.net/Tromso.htm
It is obvious that slow upward shift in the Bz field is not due to actual SSN (yellow circle) but individual storms as indicated by the Ap (blue line).
tallbloke says: May 13, 2012 at 6:11 pm
Heh. Keep going Leif, almost flat now. Just another few passes with the iron on that data.
There was (looks like 5 days) workshop last week in Bern chaired by L.S., but he has not come up with any info as yet.
http://www.issibern.ch/program/pdf/agenda_may_sep12.pdf
I have no idea what went on there, but do sincerely hope that the participants were nicer to each other than those on a display in the Bern cathedral.
http://www.sacred-destinations.com/switzerland/images/bern/munster/resized/d80_a_174.jpg
Svalgaard gone underground ?
Proposed at Bern Workshop:
- Group SSN is flawed and should be abandoned
- No evidence for Grand Maximum from ~1945-1995
My attempts to get any info about results have failed.
On the basis of Steve McIntyre’s hypothesis that positive results are trumpeted quickly….
New discovery that may confirm my hypothesis of possible sun-Jupiter electro-magnetic feedback
‘Superflares’ erupt on some Sun-like stars
The flares on our Sun are thousands of times punier than those on similar stars, Kepler observations suggest.
http://www.nature.com/news/superflares-erupt-on-some-sun-like-stars-1.10653
How could such magnetic lightweights generate superflares? Schaefer and others have previously suggested that magnetic interactions with nearby Jupiter-like planets could be to blame2. “In a [regular] solar flare, you have magnetic fields coming out of one sunspot and going into its companion sunspot and those get twisted and they break,” he says. Instead, he says, the magnetic field could go out of the superflare star and connect to a ‘hot Jupiter’ nearby, acting like a rubber band connecting the two. As the planet orbited, the field would tauten, getting stronger by drawing the planet closer, until it ultimately snapped, releasing massive amounts of energy.