An 11 year solar signal in the atmosphere
A 10 year old paper in JGR unearthed a slight solar effect in the atmosphere and whilst the paper is mentioned in various blog comments around the netnote, a quick search suggests it hasn’t had direct exposure. No harm done if it has.
Subset of Figure 4 from the paper, y-axis is atmospheric pressure hPa. Above is a hovmoller diagram.
Eleven-year solar cycle signal throughout the lower atmosphere
K. Coughlin and K. K. Tung
Journal of Geophysical Research: Atmospheres
A statistically significant atmospheric signal, which represents the influence of solar radiation changes on our climate, is found in global data (1958–2003). Using a nonlinear, nonstationary time series analysis, called empirical mode decomposition, it is shown that atmospheric temperatures and geopotential heights are composed of five global oscillations and a trend. The fourth mode is synchronized with the 11-year solar flux almost everywhere in the lower atmosphere. Statistical tests show that this signal is different from noise, indicating that there is enhanced warming in the troposphere during times of increased solar radiation.
The paper mentions Ultra Violet variation “Over each 11-year solar cycle the total energy output of the Sun varies by about 0.1% and its ultraviolet radiation fluctuates by 6–8%, with higher irradiance values during solar maxima than during solar minima.”
The effect is least at the surface “high natural variability in the atmosphere close to the surface”
Their lack of comment: “We refrain from commenting on the fifth mode since the data record contains only two periods of this oscillation” strikes me as odd since this looks about correct for a solar magnetic signature. Visually do I see a falling off as the polar field is telling us? (we have 10 years of hindsight)
They report the usual: “The nonlinear trend indicates warming in the troposphere in recent decades. A similar result at 30 hPa in the lower stratosphere has been shown by Coughlin and Tung , except that the secular trend in the stratosphere indicates cooling. These trends are consistent with the anticipated effect of increasing greenhouse gases.”
Consistent-with is sitting on the wall.
I point out there is a difference between an effect as shown and for example atmospheric temperature variations, perhaps a subtle point intended to reduce excessive claims made in blog comments. The paper does say “We conclude that the atmosphere warms during the solar maximum almost everywhere over the globe” and yes my point will seem contradictory, yet the lack of any obvious sunspot effect is a warning. (I unearthed a surface effect some time ago but don’t recall on which datasets, about +0.1K, too weak to make a fuss about)
Perhaps a 10 year old paper has been shown invalid. If so please tell me.
Extending the work by 10 years might be possible and illuminating. Any takers?
I think a good discussion to do with this paper is understanding how the result was achieved and any further applicability. Quite likely the wavelet folks will be along since there is a commonality in factoring a whole into components (words chosen carefully).
Adding yet another facet flowing from considering layers, the work of Christopher Essex’s seminal 1984 works. This tends to lead to a more general problem with GCM as implemented, which almost pointedly do not use the alternate Net Exchange Formulation, perhaps to do with fewer possibilities for fiddle factors. This seems to originate from two sources, one science and the earlier, engineering.
Finally that leaves a conundrum for me. I think I have twigged why there is so much confusion over “back radiation” but how to get this across clearly when it is a sea change in thinking is a poser. I want a pling moment. This is related to GCM and NEF.
Briefly we do not take into account atmospheric pressure when weighing apples because it is a fixed field pressing from all directions, cancels.
So why is the thermal radiation fixed field used? This goes as far as instrumentaion which must inherently cancel the fixed field but then is artifically computed and added to the supposed instrument readings! Pyrgoemeter is a case in point, Kipp & Zonen being a manufacturer showing in manuals how to do this.
NEF deals with energy transfer, fixed field is not involved. Paper at the top deals with pressure levels.
note) I do not know who first cited the paper so I cannot attribute them.
Jaynes 1980 paper might be of interest, deals with history
THE MINIMUM ENTROPY PRODUCTION PRINCIPLE
One of the three Essex 1984 papers, this one open access.
Minimum entropy production in the steady state and radiative transfer
A fairly recent NEF paper (2011)
Present and Last Glacial Maximum climates as states of maximum entropy production
Post by Tim