(Perturbation Calculations of Ocean Surface Temperatures.)
Guest essay by Stan Robertson, Ph.D., P.E.
1. Introduction
It is generally conceded that the earth has warmed a bit over the last century, but it is not clear what has caused it, nor whether it will continue and become a problem for humanity. There is a possibility that some of the warming has been caused by anthropogenic greenhouse gases, but it is also likely that the sun has been partially responsible. The arguments that are advanced to say that humans caused it and that it will become a serious problem rely on models that have not been validated and positive feedback effects that have not been shown to exist, at least at the hypothesized levels of effectiveness. The apparent weakness in the argument that the sun has been a major contributor is that satellite measurements of Total Solar Irradiance (TSI) have not shown changes large enough to have directly produced the warming of the earth over the last half century. But what about indirect effects? Is it possible that the sun exerts control in some indirect way? In these notes I recapitulate the evidence that this is the case by showing that the variations of TSI cannot provide the energy that is necessary to account for the warming of the oceans during solar cycles.
TSI, as measured above the earth’s atmosphere varies by about 1.2 watt/m2 over a nominal eleven year solar cycle (h/t Leif Svaalgard) primarily at wavelengths shorter than 2 micron. The dominant harmonic variation of TSI would thus have an amplitude half this large, or about 0.6 watt/m2. About 70% of this enters the earth atmosphere. Averaged over latitudes and day/night cycles, about one fourth of this 70%, or ~0.11 watt/m2, on average, enters the upper atmosphere. Since only about 160 watt/m2 of 1365 watt/m2 of incoming solar radiation at wavelengths less than 2 micron reaches the earth surface, the amplitude of short wavelength TSI reaching the earth surface would be only (160/1365)x0.6 = 0.07 watt/m2. However, about half of the difference between 0.11 and 0.07 watt/m2 eventually reaches the earth surface as scattered thermal infrared radiation at wavelengths greater than 2 micron. Thus the average amplitude of TSI reaching the earth surface in all wavelengths would be about 0.09 watt/m2. So the question is, just how much sea surface temperature variation can this produce?
Several researchers, including Nir Shaviv (2008), Roy Spencer (see http://www.drroyspencer.com/2010/06/low-climate-sensitivity-estimated-from-the-11-year-cycle-in-total-solar-irradiance/) and Zhou & Tung (2010) have found that ocean surface temperatures oscillate with an amplitude of about 0.04 – 0.05 oC during a solar cycle. (In fact, all of the ideas that I am presenting here were covered in Shaviv’s work, but it has not gotten the attention that it deserves.) Using 150 years of sea surface temperature data, Zhou & Tung found 0.085 oC warming for each watt/m2 of increase of TSI over a solar cycle. Although not strictly sinusoidal, the temperature variations can be approximately described in terms of a dominant sinusoidal component of variation with an 11 year period. Thus the question to be answered at this point is, can 0.09 watt/m2 amplitude of variation of TSI entering the oceans produce temperature oscillations with an amplitude of 0.04 – 0.05 oC?
The answer to this question depends on the average thermal diffusivity of the upper oceans. That is an unknown, but not unknowable, quantity. Thermal diffusivity is the ratio of thermal conductivity to heat capacity. The upper 25 to 100 meters of oceans are well mixed by waves and shears. These are mixing zones with high thermal diffusivity and correspondingly small temperature gradients. Diffusivities are lower at greater depths. Bryan (1987) has found that thermal diffusivities ranging from 0.3 to 5 cm2/s are needed to account for the temperature profiles below the mixing zone. In my first trial calculations of the energy flux necessary to account for the temperature variations, I tried values of thermal diffusivity in the range 0.1 – 10 cm2/s and found that the TSI variations were generally inadequate to produce the sea temperature variations over a solar cycle. But there was wide variation of calculated energy flux. Larger values of thermal diffusivity required more heat because more was able to penetrate to the depths, but even for 0.1 cm2/s, the required input was double the TSI variations that reach the earth surface. Fortunately, there is a way to constrain both the value of the thermal diffusivity and the heat input. It consists of first matching the measured trends of surface temperatures and ocean heat content over time. Measurements of these were reported by Levitus et al. (2012) and are available from http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/ .
In the calculations described below, I have used the data from 1965 to 2012 for ocean depths to 700 meters. Sea surface temperatures and ocean heat content began to increase after 1965. Only about a third of the increase of heat content occurred at depths below 700 meter. Since little heat migrates below this depth over 11 year solar cycles, it is preferable to use the 0 – 700 m data for the purpose of calibrating the thermal diffusivity
2. Heat Transfer Perturbation Calculations
For the calculation of sea surface temperature and sea level changes, we can treat the variations of radiations entering and leaving atmosphere, lands and oceans as minor perturbations on an earth essentially in thermal equilibrium. Ocean mixing zones, thermoclines and other features of the temperature profiles remain largely as they were while small radiant disturbances produce minor variations of temperature starting from zero, and imposed at each depth. Thus the effects of these disturbances can be modeled as one-dimensional energy flows into a medium at uniform temperature. Such “perturbation calculations” are among the most powerful analysis techniques used by physicists and engineers and are widely used. The energy equation to be solved in this case is:
http://i1244.photobucket.com/albums/gg580/stanrobertson/equation_zpscea297ad.jpg
Where T is the temperature departure from equilibrium at depth , z, and time, t. q is a perturbing radiant flux entering the surface, u the absorption coefficient, c is absorber heat capacity and k its thermal conductivity. The rate of heat transfer by conduction processes is controlled by the thermal diffusivity, which is the ratio k/c.
As a one dimensional heat flow problem, it is straightforward undergraduate level physics or engineering to numerically solve the equation above for the expected changes of surface temperature as surface radiant flux varies. In my calculations, temperature changes were calculated for 1.0 meter increments of depth in the oceans. Two cases were considered. In one
case the surface radiation perturbation was assumed to increase linearly with time. This corresponds to the ocean conditions for the period 1965-2012. In the second case, it was assumed to vary as a cosine function of time with the 11 year period of the solar cycle. The cosine function provides both some positive and some negative variation in the first half cycle, which helps to minimize the transients of the first few years.
I treated q and thermal diffusivity, (k/c), as input parameters that were chosen to provide agreement with the observed sea surface temperature variations and ocean heat content measurements (https://www.ncdc.noaa.gov/ersst/ ). The absorption coefficient, u, was entered in piecewise fashion. Only the deep UV radiations penetrate to depths below 10 meter, but conduction takes energy to much greater depths. For the values of u chosen, only 44.5% of the surface energy flux goes deeper than 1 meter, 22.5% below 10 meter and 0.53% to 100 meter (h/t Leif Svalgaard). Thermal diffusivity of oceans was assumed to be 0.3 cm2/s below 300 m. This accords with Bryan’s estimates below the mixing zone, but little change of results occurred for values as low as 0.1 cm2/s. The required heat inputs are relativity insensitive to the thermal diffusivity below 300 meter. For the shallower depths, thermal diffusivity was varied until trends in accord with observed temperatures and heat content were produced.
It is necessary to maintain an energy balance at the sea surface in approximate equilibrium with the incoming solar radiation. As estimated by Trenberth, Fasullo and Kiehl (2009), about 160 watt/m2 enters the surface, on average. At a mean temperature of 288 oK, the sea surface will emit about 390 watt/m2 of surface thermal infrared radiation at wavelengths longer than about 2 micron, however, about 84% of that is returned as back scattered radiation. The rest of the energy balance is provided by evaporation and thermal convection, which remove about 59% of the heat from the surface. From the standpoint of merely wanting to know how much heat is required to change the ocean surface temperature, it is possible to maintain a proper energy balance without delving into the messy details of evaporation, convection and infrared absorption in the first few millimeters of water. The temperature variations at one meter depth will not be measurably different from those at the surface for the thermal diffusivities of interest here. If we merely want to know what net energy flux entering the surface is required to make the water temperature at one meter depth oscillate with an amplitude of 0.04 – 0.05 oC , then all we need to do is account for the outgoing surface infrared emission and let 41% (160 watt/m2 / 390 watt/m2 = 0.41) escape. At the present 288 oK, the earth radiates an additional 5.42 watt/m2 for each 1 oC increase of surface temperature. In the case of surface temperature being perturbed by 0.04 oC, an outgoing additional 0.22 watt/m2 would be generated and 0.09 watt/m2 was allowed to escape. This nicely balances the amplitude of TSI variations that reach the earth’s surface.
3. Linear heating:
In these calculations, the aim was to find the heat input and thermal diffusivities necessary to account for the observed surface temperature increase (http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/ )Extended Reconstructed Sea Surface Temperature) and the increased ocean heat content (OHC 700) that have been reported by NOAA. Since surface temperatures had not been increasing in the early 1960s, but began to increase in the last half of that decade, I chose to start calculations with linearly increasing heating in 1965. I found that the ocean heat content to a depth of 700 meters was quite sensitive to the thermal diffusivity used. The best results that I have been able to obtain were for a thermal diffusivity of 1 cm2/s to 300 meter depth and surface heat input increasing at a rate of 0.31 watt/m2 per decade. These are shown on the graph below with calculated trends shown by the green and black lines. On a time scale of 50 years, most of the heat accumulates at relatively shallow depths. To better reflect a realistic thermal diffusivity for greater depths, I used a lower value of 0.3 cm2/s below 300 meter. That has little practical effect on a 50 year times scale, but would be necessary if one wanted to extend the calculations for several centuries while surface heating perturbations had time to penetrate to much greater depths.
http://i1244.photobucket.com/albums/gg580/stanrobertson/OHC700_zpsb9e34e91.jpg
Figure 1. Ocean heat content 0 – 700 meter and surface temperature trends according to NOAA. Blue and green lines show trends calculated for the parameters shown.
These calculations establish some parameters that do a good job of representing the thermal behavior of the upper oceans, however, if one looks closely at the data trends in the graph, it is apparent that both surface temperature and ocean heat content have considerably slowed their rates of increase in the last decade. This makes it unlikely that greenhouse gases are the cause of the rate of heating needed to explain the previous trends because their effects should have become enhanced rather than diminished. It might also be noted that a similar warming trend occurred in the first half of the previous century before anthropogenic greenhouse gases could have contributed significantly. Thus it is more likely that both warming periods had natural origins.
Obtaining simultaneous fits to the ocean heat content and sea surface temperature trends with only two free parameters, thermal diffusivity and surface heating rate, is quite confining. Acceptable, but noticeably worse, fits than shown above, were obtained with thermal diffusivities ranging from 0.8 to 1.2 cm2/s and heat inputs ranging from 0.29 to 0.33 watt/m2. Based on previous calculations for sea level data, I was initially inclined to think that larger thermal diffusivities would be necessary, but larger values let more heat penetrate to greater depths than the amounts of heat reported by Levitus et al. In addition, I was chagrined to learn that most of the variation of sea level that accompanies solar cycles is caused by evaporation rather than thermal expansion.
Solar Cycles:
The process of choosing thermal diffusivity and surface heating rates to accord with observations provides a sound basis for calculating what to expect for the temperature variations during solar cycles. In this case we can use the thermal diffusivity of 1 cm2/s that is required of the ocean heat content results as an input parameter and choose the heat input that is required to produce temperature variations of 0.04 – 0.05 oC amplitude. Producing sea surface temperature variations with an amplitude of 0.04 oC requires a surface heat input of 0.33 watt/m2, as shown below:
http://i1244.photobucket.com/albums/gg580/stanrobertson/solarcycle10_zpsa3b8b0ee.jpg
Figure 2. Radiant flux, ocean temperature oscillations, and sea level variations for three solar cycles of eleven years each. The entering flux shown here is the value of q = 0.33 watt/m2 needed to drive the variations of surface temperature of 0.04 oC with ocean thermal diffusivity of 1.0 cm2/s to depth of 300 m. The amplitude of thermosteric rate of change of sea level was 0.47 mm/yr. Temperature lags the driving energy flux by 15 months. The thermal expansion coefficient of sea water used here was 2.4×10-4/ oC.
I believe that this settles the issue of what is required to produce sea surface temperature oscillations with an amplitude of 0.04 oC. The solar TSI variations that reach the earth’s surface are smaller than the 0.33 watt/m2 needed to account for sea surface temperature variations by a factor of 3.6 for this smallest estimate of sea surface temperature variability.
Although the estimated 0.33 watt/m2 that is required to explain the surface temperature variations is large compared to the amplitude of TSI variations that reach the surface, it is still only about two parts per thousand of the 160 watt/m2 of solar UV/VIS/NIR that reaches the earth surface. There are many possible ways in which the sun might modulate the surface energy flux to this extent. These include modulation of cloud cover and small spectral shifts in the energetic UV that might modulate ozone absorption or produce shifts of the effective sea surface albedo. It would seem to be a fairly direct radiative effect, rather than feedback, since it must vary in phase with the solar cycle.
In summary, my calculations based on energy conservation considerations imply that the sun modulates the ocean temperatures to a much greater extent than can be provided solely by its TSI variations. The great question that desperately needs an answer is how does it do it? It should be easily understood that solar effects would not necessarily be confined to cycles. More likely, the sun has been the driver of the large changes of temperatures of the Roman and Medieval warm period, the Little Ice Age, and the recent recovery from it without requiring large changes of its own irradiance. When we understand how the sun does this, we will have begun to understand the earthly climate.
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Biographical note:
Stan Robertson, Ph.D, P.E, retired in 2004 after teaching physics at Southwestern Oklahoma State University for 14 years. In addition to teaching at three other universities over the years, he has maintained a consulting engineering practice for 30 years.
References:
Bryan, F., 1987: Parameter Sensitivity of Primitive Equation Ocean General Circulation Models. Journal of Physical Oceanography, 17, 970-985. (PDF available here http://journals.ametsoc.org/doi/abs/10.1175/1520-0485%281987%29017%3C0970%3APSOPEO%3E2.0.CO%3B2
Levitus, S. et al., 2012 World ocean heat content and thermosteric sea level change (0–2000 m), 1955–2010, Geophysical Research Letters, 39, L10603, doi:10.1029/2012GL051106, 2012 http://onlinelibrary.wiley.com/doi/10.1029/2012GL051106/abstract
Shaviv, Nir 2008, Using the oceans as a calorimeter to quantify the solar radiative forcing, Journal of Geophysical Research, 113, A11101 http://www.sciencebits.com/files/articles/CalorimeterFinal.pdf
Trenberth, K., Fasullo, J., Kiehl, J. 2009: Earth’s Global Energy Budget. Bull. Amer. Meteor. Soc., 90, 311–323. doi: http://dx.doi.org/10.1175/2008BAMS2634.1 www.cgd.ucar.edu/staff/trenbert/trenberth.papers/TFK_bams09.pdf , Fig. 1
Zhou, J. and Tung, K. ,2010 Solar Cycles in 150 Years of Global Sea Surface Temperature Data, Journal of Climate 23, 3234-3248 http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3232.1
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Stan Robertson,
Thank you for a tightly reasoned discourse that will be useful to encourage more research on how the sun modulates the ocean temps; given that a significant set of observations reasonably show that there is a basis for saying that it has.
Personal Note: the solar discussions over the years at WUWT constitute, I think, the best prototype science dialog in the climate blogosphere. A certain Northern California based Dane has been central to the discourse; replying to virtually every single comment addressed to him (thanks Leif).
John
Not only “The solar d**niers”
Let us recall the famous work – paper by H. von Storch (http://www.academia.edu/4210419/Can_climate_models_explain_the_recent_stagnation_in_global_warming): “Of the possible causes of the in consistency, the underestimation of internal natural climate variability on decadal time scales is a plausible candidate, but the influence of UNACCOUNTED EXTERNAL forcing factors or an overestimation of the model sensitivity to elevated greenhouse gas concentrations cannot be ruled out. The first cause would have little impact of the expectations of longer term anthropogenic climate change, but THE SECOND and particularly the third would. […]”
“…variations in solar insolation or activity still require rather speculative [but not impossible] amplification mechanisms that could contribute to the observed recent decrease in global warming.”
… speculative … – it’s not the fault of the skeptics that insufficient research relates to the great very important topic.
My “favorite” quotation with Bard and Frank: “Overall, the role of solar activity in climate changes — such as the Quaternary glaciations or the PRESENT GLOBAL WARMING — remains unproven and most probably represents a SECOND-ORDER EFFECT.”
And this is what must be examined …
the sun does it now go figure out how
It ain’t simple, but the data shows that as the sun twinkles the Earth shakes
http://www.vukcevic.talktalk.net/SSN-NAP.htm
http://www.vukcevic.talktalk.net/APS.htm
Since 1955, the Earth has accumulated about 19 x 10^22 joules of Energy.
The Sun, however, has put down on Earth about 22,400 x 10^22 joules of Energy over that same timeframe.
http://s9.postimg.org/7iqicpfsv/Earth_Energy_Accumulation_vs_Solar_Energy_Q2_201.png
That is where you answer is. We are thinking about the very small changes in Solar Irradiance, but the Sun is still hitting the surface with 386.4 x 10^22 joules of Energy/photons each and every year.
Solar energy can accumulate in the Earth’s rocks, water, vegetation, ice and atmosphere over any time period. It accumulates and drawsdown on a per second basis, each hour, every day, certainly throughout the seasonal cycle and even annual or decadal timeframes.
For example, if your live in the Northern Hemisphere, your location is at its coldest about January 19th each year. For the next 182 days, your backyard then starts to accumulate about 0.1 W/m2 of energy each day (on average) until your backyard becomes the warmest it will get on July 19th. Then the cycle reverses and your backyard loses about 0.1 W/m2 until January 19th again.
Since this clearly happens, there is no reason why it doesn’t also change from year to year so that January 19th has 0.3 W/m2 more of energy than it had the previous January 19th. Maybe it is 0.5 W/m2 more than January 19th of 25 years earlier.
Start accumulating the numbers over time and the answer could emerge from that because it is more realistic of what really happens. The rocks and soil and water and ice accumulate/drawdown energy over time.
And
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Bruce Cobb,
I assume you are referring back to Mosh’s interjection of unicorns into the wonderful thread initiated by Stan Robertson’s well done sun/ocean essay.
I think Mosh has performed, with his unicorn interjection, an intellectual acrobatic known as ‘the inverted Black Swan Maneuver’. It works within the so-called lukewarmer meme, otherwise it does not.
John
For the topic of this post (also last comment) is important this textbook: Impacts of multi-scale solar activity on climate. Part I: Atmospheric circulation patterns and climate extremes, Weng, 2012. (http://link.springer.com/article/10.1007%2Fs00376-012-1238-1), this proposal (of it) I recommend to all, but especially authors of IPCC reports:”The atmospheric amplifying mechanism indicates that the solar impacts on climate should NOT BE SIMPLY ESTIMATED by the magnitude of the change in the solar radiation over solar cycles when it is compared with other external radiative forcings that do not influence the climate in the same way as the sun does.”
Not just the sun’s energy variation, but also the frequency domain variations, and particle output variations (and thus the electrical charge inherent in our atmosphere). We need to holistically think of these parameters to be able to come to grips with the sun’s effect on our climate.
To focus solely on solar energy output variations restricts us to a very myopian view of our immediate universe.
To think that straightforward energy inputs are “amplified” (some kind of positive feedback) requires alot of evidence. Nature does not easily produce positive feedback (ice/snow and resulting albedo-change effects are an exception). Negative feedback rules. Remember CO2 & purported warming amplifications? Same general situation here.
lsvalgaard says:
October 10, 2013 at 11:32 pm
The albedo is basically determined by clouds. It takes a lot of energy to make clouds. The solar wind does not have a lot of energy.
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chemistry provides the answer. the solar wind acts as a catalyst to cloud formation. As a catalyst, the solar wind alters the rate of cloud formation without any requirement to supply energy.
Many mechanism have been proposed by which this can happen. Currently, the cause is unknown. What the author has shown is simply that such a mechanism much exist, outside of TSI.
Again, like the discovery of the outer planets. We knew they must exist because of the effect they had, long before they were discovered.
I have had lot of confrontations with the Stanford Solar Supremo, but he is correct, TSI doesn’t vary sufficiently, but it supplies enough energy to the point where all of the Arctic’s ice could disappear, as it did in the past. .
The Arctic ice was not melted by variability in the TSI, it was melted by the warm Atlantic currents. Heat is absorbed in the equatorial regions, and what varies far more then the incoming TSI is ratio of energy radiated back to the space and the energy moved pole-ward by currents. Only natural non-climatic force that can shift this ratio is the Earth’s tectonics.
http://www.vukcevic.talktalk.net/APS.htm
No, the unicorns all died when they sacrificed themselves for us to take all the excess heat to the bottom of the ocean. My proof is that there is now not even one unicorn to be found.
@tom0mason>”Not just the sun’s energy variation, but also the frequency domain variations, and particle output variations”
But TSI encompasses _all_ (as in ‘total’) the energy in the Sun’s elecromagnetic radiation (EMR) spectrum. What other ‘frequency domain’ did you have in mind?
Solar energy emitted by particles is miniscule, in comparison to EMR.
John Day says:
October 11, 2013 at 6:34 am
Solar energy emitted by particles is miniscule, in comparison to EMR.
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A virus is miniscule. The energy it supplies is miniscule at best. For all intents and purposes zero. Yet it can radically alter the chemistry of objects that in comparison are almost infinitely more massive.
Leif, I believe that you have stated in past comments (not on this thread, but on this blog) that you believe that the dearth of sunspots and the present expected solar minimums will not lead to declining temperatures. And you believe that the correlation between, say, the Maunder Minimum and the Little Ice Age is largely or even exclusively coincidence. Can you expand upon that?
It seems to me that TSI may not be the only solar mechanism that affects our climate or global temperature. As some commenters have proposed, there could be other mechanisms at play, ripple effects as it were. For example, deep solar minimums may somehow unleash more volcanic eruptions which cool the earth, albeit in apparently short timeframes.
Any thoughts? I don’t find this addressed on your blog, but may have missed it. Any insight would be appreciated.
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lsvalgaard says:
October 10, 2013 at 9:54 pm
Please explain why that doesn’t matter and why the bottom of the ocean after billions of years of conduction has not reached the average yearly surface temperature. Again: I’m trying to learn, not to argue.
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As you say, deep ocean water @ur momisugly 4C has 15C avg water-temp above, and 100C rock-temp just a mile or so below the sea-bottom, thus one has to conclude that it’s highly insulated, and that heat-transfer rates in/out of those ocean depths are very small.
They’re working w/300m depth — that seems roughly correct for a mixing zone, but IMO means changes below that have little effect on climate and no “pipeline-heat” there.
beng says:
October 11, 2013 at 6:25 am
To think that straightforward energy inputs are “amplified” (some kind of positive feedback) requires alot of evidence.
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a catalyst does not involve positive feedback. look in the mirror and you will see nature using extremely complex catalysts to produce a result that would be impossible otherwise. these catalysts do not add energy to the reaction. they lower the energy at which the reaction can take place, and thus increase the reaction rate, without adding any energy to the reaction.
I’m still curious about the claim of 0.33 W/M2.
Joanna Haigh published in the royal society that TSI has increased by 3-4 W/M2 since the end of the LIA. If you take that only 45% of that reaches the surface, [we’ll make it easy and say 50%], that equates to 1.5-2 W/M2 increase since the LIA. That is considerably greater than 0.33 W/M2, and given that the Ocean stores heat, moves it around, releases it, etc … it would seem that the OP presentation is support that the TSI itself is in fact a significant contributor.
beng says:
October 11, 2013 at 6:58 am
As you say, deep ocean water @ur momisugly 4C has 15C avg water-temp above, and 100C rock-temp just a mile or so below the sea-bottom, thus one has to conclude that it’s highly insulated, and that heat-transfer rates in/out of those ocean depths are very small.
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unlikely. insulation cannot explain the uniformity. If the result was due to insulation there should be a gradient according to latitude. The lack of any such gradient argues that the effect is dynamic, that the cold water is in continual re-supply (from the poles?), and that the resupply is massive. The 4C temperature is explained as a result of the expansion of water above and below 4C.
@berple>”A virus is miniscule. …”
Yes, but tom0mason was addressing “particle output variations“, so changes in the solar wind, when it’s not firmly established/accepted that the solar wind per se has any lasting impact on climate. So would you expect changes in that regime to have more impact? (Not cosmic rays, BTW, they don’t come from the Sun)
Personally, (since we now know the unicorns died) I think it has to be changes in the flapping rates of those butterflies on the other side of the world. We know they can change the course of mighty hurricanes.
:-]
At a mean temperature of 288 oK, the sea surface will emit about 390 watt/m2 of surface thermal infrared radiation.
This is simply misunderstood, it will radiate that much if air above sea is 0ºK.
This is pure fictious. If the surface temperature is 288 K, air above it might be 286K. Temperature difference is only approx 2K, when you calculate using these with Stefan Bolzman law or look from this engineering toolbox table, you can see that heat radiated is only few watts/m2. http://www.engineeringtoolbox.com/radiation-heat-transfer-d_431.html . Heat radiation is a minor part of heat radiation from surface to air, approx 98% is heat transfer via conduction. CO2 can trap very specific waveleghts and that happens in few meters above surface, that heat is transfered very soon to other atmosphere molecules via convection. CO2 has nothing to do with warming atmosphere, in contary it is a good cooler, cause as a 3- atomic molecule it can emit energy to space in top of atmosphere. Without increased CO2 we would have much warmer atmosphere, because less energy is radiated to atmosphere. CO2 is much more cooler than warmer.
Lief, et. al.;
‘TSI does not vary sufficiently . . .’
Vary sufficiently from what? Our observational time frame is completely unacceptable as a touchstone. The Earth has been warming, rather suddenly and quickly for some 20 thousand years, before that it was gradually cooling for some 125 thousand years, before that it warmed, suddenly and quickly for about 20 thousand years.
Do we know what the earth’s mean equilibrium temperature should be at a given TSI?
Do we know what the TSI was 150 thousand years ago? 50? 10?
The oven is on. Its warming up. How long does it take to reach equilibrium? If you cannot look at the Sun’s TSI and predict, very accurately, what the Earth’s equilibrium heat content (notice that; heat content, not surface T) should be and how long it will take to reach that equilibrium, then just about everything else the ‘climate witchdoctors’ are talking about is next to useless.
We do not know the variability of the sun. The reconstructions and so forth that I have seen go back no farther than 10 thousand years. The earth, according to antarctic ice core reconstructions as a proxy for global temperature, started warming, as I said, some 20 thousand years ago, quite suddenly and quite rapidly following a long cooling period.
Lief, you claim that the TSI change is insufficient to cause the change in surface T. How do you know what governs surface T if you cannot even model the overall heat content of the planet (there’s that heat content thing again)? The oceans certainly have a lot more control over the temperature of the atmosphere than CO2. The Cloud experiments at CERN could overturn the entire CAGW industry. And, as a final ‘coup de grace’ to this rebuttal of your argument; if delta TSI is insufficient to cause the observed warming because it doesn’t provide for enough additional energy at the surface, consider that CAGW provides for the observed warming sans any additional energy whatsoever. Zero. Maybe a 9% TSI equates to just enough added shortwave reachi ing the Earth to increase global photosynthesis just enough to result in higher CO2 . . . maybe CO2 induced global warming is itself a positive feedback of a very slight increase in TSI?
In short; I disagree that you can shoot down TSI out of hand, based on some authoritative knowledge of the downwelling radiation, based on the fact that we do not have a model to get us to equilibrium and thermal inertia for the Earth. Without that little else can be said.
Even our scientists (at least the honest ones) admit that there is a great deal more they don’t know than what they do know.
Ulric Lyons says:
October 11, 2013 at 3:19 am
Looking how well the SABER data follows the geomagnetic signal, the solar wind appears to be responsible for a large proportion of the heating of the upper atmosphere.
Up there the density is a billionth of sea-level density so there is almost no heat and hot air does not descend.
David Riser says:
October 11, 2013 at 3:49 am
I would like to point out that the farthest away satellite was launched in 2010 and does not provide data to the TSI dataset.
The SOHO satellite which forms the basis for the PMOD TSI dataset was launched in 1995.
So your still measuring from within the atmosphere for this data
Not at all. Once you are above 20 km [the usual definition of TOA Top of Atmosphere] the atmosphere is so thin that it does not influence TSI to the extent we can measure it.
Madman2001 says:
October 11, 2013 at 6:56 am
the Maunder Minimum and the Little Ice Age is largely or even exclusively coincidence. Can you expand upon that?
http://www.leif.org/research/Does%20The%20Sun%20Vary%20Enough.pdf
@me>(Not cosmic rays, BTW, they don’t come from the Sun)
Yes, GCR’s are modulated by the Sun. But still those effects on climate not firmly established, in spite of recent research by Svensmark et all.
The Earth’s magnetic field acts a shield to protect us from the ravages of solar wind. Else our atmosphere (and climate) would have been stripped away eons ago.
The obsession with radiation is a hold over from the cold war, when nuclear weapons and radiation fears dominated the world, both politically and scientifically. This obsession drives the IPCC in its obsession with CO2 and LW radiation.
We forget that Nature does not rely on brute force alone. Nature is also extremely subtle. Time and time again nature shows us that what we believe is impossible is due to the limitations of our minds, not the limitations of the universe around us.
The weather, the weather, everyone talks about, never does a thing about……..stay tuned for the next artificial crisis and chaos. A opportunity for change! 😉