(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
I’m sticking with Zeus, Umvelinqangi, Taranis, Parjanya, Stribog, and the rest of the gang. Don’t need any difficult maths.
Steven Mosher says:
October 10, 2013 at 7:55 pm
Even half is preposterous, based upon feedback assumptions not only not in evidence but contrary to all actual objective data & observations. There was an accidental correlation in the 1990s between increasing CO2 & rising T, but far more often in climate history there has been negative or no correlation. The effect from CO2 is demonstrably & prima facie negligible to non-existent, except possibly as a minor positive feedback, since naturally warming oceans give up the gas.
To quote the late, great Reid Bryson, “You can go outside and spit and have the same effect as doubling carbon dioxide”.
But please say where IPCC states that it’s only half & to what they attribute the rest. Thanks.
Steven Mosher: “Prove its not unicorns Pat.”
Small perturbation in a climatological system are not Unicorns. Which are defined as horses with a pointy thing on the front. And, we should note, are just as mythical as your ability to reason.
Bill Taylor says:
October 10, 2013 at 5:12 pm
strange that anyone could possibly claim the sun really doesnt have much impact on our climate……
Try this analogy – gasoline powered autos. If one reads the ads for vehicles there are all sorts of differences and wonders to behold. There is a continuous variable transmission (old idea, new technology) touted as providing better gas mileage. Just one of many. All auto companies use such things to claim they can provide you with a better product. None of the car companies claim its the gasoline that does it.
The Sun is there. We understand that. What we don’t have are the processes (cosmic, oceanic, magnetic, solar, or whatever) that cause the shorter climatic fluctuations. Several folks on this (and other) posts are just saying “show me.”
While this is an interesting article, there are serious problems with the underlying data. TSI measurements are based on several different satellites since 1979 (3 different ones). So there is about 34 years of data that is taken from the bottom of the outermost layer of the atmosphere. So TSI is probably not being properly measured, I am sure its reasonably precise for each of the three satellites for where they were at in the atmosphere, however since its measuring inside the atmosphere we don’t actually know what or how much is making it to parts of the atmosphere away from where the satellites orbits were/are. Additionally TSI has a very short approximately 3 cycles of data which is probably not enough to know what its potential long term flux is.
In addition to TSI the upper level of ocean temperatures is measured very well and its reaction to TSI over the entire body of water as well as the mixing effects of AMO and PDO make it very unlikely that we can calculate how much energy is actually accounted for by TSI flux. Most likely I would think that the energy entering the system is coming from the sun If there is a flux that matches TSI flux then most likely the sun is the direct or indirect cause.
Stan is probably right, if we can figure this out, we will get a much better understanding of the climate system. But what we really need is better data. For the most part were just scratching a small part of a very large surface in our attempts to measure the Earth.
v/r,
David Riser
Woops,
In addition to TSI the upper level of ocean temperatures is measured very well and its reaction to TSI over the entire body of water as well as the mixing effects of AMO and PDO make it very unlikely that we can calculate how much energy is actually accounted for by TSI flux
should be
In addition to TSI the upper level of ocean temperatures is not measured very well and its reaction to TSI over the entire body of water as well as the mixing effects of AMO and PDO make it very unlikely that we can calculate how much energy is actually accounted for by TSI flux
v/r,
David Riser
Steven Mosher,
You must know a lot about unicorns. Thank you for sharing the knowledge that unicorns have squate roots and that they are variable. The variable part is of course a given.
Plankton convert radiant energy into to chemical energy via photosynthesis. Could it be a variability concerning them? e.g. http://www.icess.ucsb.edu/bbop/
Paul, you must be joking. The Sun has nothing to do with the heating of your yard in the daytime and its cooling at night. A moment’s thought will clear your head. But given the state of scientific knowledge held by adults the world over, there is very likely another guy on the opposite side of the planet who is as convinced as you with a twist. While you are pointing to the Sun as the driver of your daytime yard heating, the guy on the opposite side of the globe is pointing at the lack of the Sun as the driver if his nighttime cooling.
You do realize, I hope, that the cause is the Earth’s rotation on its axis? I know it seems I am stating the obvious but many people here have used the same illogical statement to support their belief that the Sun is the driver of trends.
And the answer is,,,,
Those randy little photo plankton and diatoms are exponentially stimulated by the increase in TSI; the resulting sexual activity warms the ocean.
Far fetched you say ? Just look at the energy released in this thread by just a few small inputs, due in large measure to an effect known as Onan’s Razor.
bones says:
October 10, 2013 at 7:56 pm
The problem is that your calculation would apply only to a surface with no heat capacity. You are failing to consider the heat required to raise the water temperature for a considerable depth below the surface.
Your question was “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?” and I showed that it could produce such variations at the surface of the ocean.
David Riser says:
October 10, 2013 at 8:16 pm
So there is about 34 years of data that is taken from the bottom of the outermost layer of the atmosphere. So TSI is probably not being properly
Not so. One of the satellites is a million miles away, the others at 645 km and 700 km altitude, not ‘the bottom of the outermost layer’, but effectively outside the atmosphere; and TSI is measured very precisely [and accurate to one part in 2700].
Reading through this discussion has been a real eye opener for me. Leif Svalgaard is treated with respect on this blog as an expert on solar physics, and he certainly regards himself as one. And then he makes the most astounding simple errors in the arguments presented here – and insists despite very clear explanations of his errors. First he confuses the production of energy with a regulation of energy transport, and then he calculates the variation of sea surface temperature from instantaneous balance between incoming energy flux and emitted blackbody radiation.
We can all have a bad day but this is really strange.
Dr. Robertson, very good analysis. Have read it once through but I want to slow down the next pass to absorb it all. Have checked your figures through paragraph two and did noticed you are being extra conservative at each step. Nice, better to not have something for someone to pick at. Going to enjoy this one! Well, tomorrow. This is one good question.
lsvalgaard says:
October 10, 2013 at 8:53 pm
bones says:
October 10, 2013 at 7:56 pm
The problem is that your calculation would apply only to a surface with no heat capacity. You are failing to consider the heat required to raise the water temperature for a considerable depth below the surface.
Your question was “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?” and I showed that it could produce such variations at the surface of the ocean.
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So when did the ocean lose it its heat capacity? And you are bragging about an incorrect solution to a physics problem? That’s incredible to me, especially after I had extended the courtesy of a heads up on this one.
No one really has a satisfactory explanation for the global surface warming throughout recent years. But solar power could be used for more good than it currently is.
http://www.climal.com/solar-power.php
bones says:
October 10, 2013 at 9:26 pm
So when did the ocean lose it its heat capacity? And you are bragging about an incorrect solution to a physics problem?
Nobody is bragging here [at least not I] Perhaps you should consider the possibility of having presented a correct solution to the wrong problem. Circulation and convection rather than conduction are probably more important.
lsvalgaard says:
October 10, 2013 at 9:31 pm
Perhaps you should consider the possibility of having presented a correct solution to the wrong problem. Circulation and convection rather than conduction are probably more important.
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Not on an 11 year time scale. Not to mention that vertical water convection is rolled into the thermal diffusivity. The thermal conductivity of water in a lab flask would be nearly 1000 times smaller. Seems to me that you don’t understand the basic physics of the situation, so I am going to abandon arguing about it and leave you to think about it or maybe talk to one of your colleagues. It’s bed time here in the boonies.
Dr. Isvalgaard,
Do you think there is correlation between the cosmic rays and temperature historically?
I understand correlation is not causation but from what I’ve seen of Dr. Shaviv’s work he makes a compelling connection.
I understand the TSI variations as measured at the top of the atmosphere are not strong enough to explain temperature fluctuations as seen in the correlation. Are the energy measurements at the surface theoretical from what is measured at the top or are they measured at the surface?
The explanation from Shaviv seemed to be that all the energy doesn’t reach the surface because of cloud variations. Therefore the fluctuations at the bottom will be larger because sometimes the average reaching the bottom is very little (many clouds) sometimes it is very large (few clouds).
Do you think his theory is incorrect that solar winds can cause more clouds?
If he was correct do you think this could explain temperature variations?
Thank you for your time explaining this.
bones says:
October 10, 2013 at 9:41 pm
” Circulation and convection rather than conduction are probably more important.”
Not on an 11 year time scale. … Seems to me that you don’t understand the basic physics of the situation, so I am going to abandon arguing about it
I am not arguing with you, i am trying to understand what you are saying and so far I have failed. In my book a failure of the student reflects upon the teacher. In this animated graph http://www.bom.gov.au/climate/enso/sub-surf_anim.gif the rapid temperature changes over several hundred meters in a few days shows me the effect of circulation overwhelming that of conduction. 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.
Dr. Svensmark’s new paper suggests that GCRs are capable of creating cloud seeds in excess of 50 nanometers, which are of sufficient size to create clouds.
When other scientists replicate Svensmark’s SKY2 experiment and get the same results, then at least part of the puzzle of SSN flux/GCR flux/cloud cover flux/albedo flux/global temp flux can help explain part of the Sun’s affect on climate.
The SSN flux/global temp flux correlation had been well established, but the specific interactive mechanisms that create that correlation have yet to be firmly established. I do think Svensmark’s research into the Svensmark Effect had at least explained part of the puzzle, although there is heated debate on the subject.
It’s becoming increasing obvious that CAGW hypothetical assumptions that: 1) solar influences are relatively constant and thus can’t explain the 20th century warming, and 2) the lowly CO2 molecule is the ultimate climate control knob, are absurd.
The bottom line is that the longer the IPCC/governments/academia holds climate science hostage under the disconfirmed CAGW hypothesis, the longer it will take true scientists to solve the mysteries of Earth’s complex and changing climate system.
shenanigans24 says:
October 10, 2013 at 9:48 pm
Do you think there is correlation between the cosmic rays and temperature historically?
Many people have looked at this and cosmic ray hypothesis doesn’t look too good now, see e.g. http://www.leif.org/EOS/swsc120049-Cosmic-Rays-Climate.pdf [“it is clear that there is no robust evidence of a widespread link between the cosmic ray flux and clouds”] or http://www.leif.org/EOS/1303-73140Cosmic-Rays-Climate-billion-yrs.pdf [“It has already been shown by Overholt et al (2009) that the peaks and troughs in the Shaviv distribution do not correspond to crossings of the SA in the Galaxy. Here we show that the estimated intensity variations from the Shaviv distribution are also unrealistic”].
Now, you can also find papers that claim to support the hypothesis. I guess everybody has to make up his own mind what to believe. Personally, I don’t think there is a link at all.
milodonharlani
Here are all the forcings: C02, CH4,halocarbons, N2O, C0. NMVOC, No3,NH3,S02,Black Carbon, Organic Carbon, Mineral Dust, Aerosol, Aircraft (contrails), Land Use, Solar.
For 1750 to today C02 forcing is around 1.6Watts, Ch4 is around 1 watt, black carbon about .7Watts. halocarbon and N02 around .5Wwatts
so.. the non c02 stuff is around 1+ .7 +.5 or around 2.2 Watts
C02 is the largest SINGLE contributor, but if you look at all contributors its around 1.6 watts out of 3.8 or so.. thats for the forcings that are postive.
Its in Ar5. read the science before you criticize it. That’s what I learned from Steve Mcintyre and Anthony. You might consider it
lsvalgaard says:
October 10, 2013 at 9:54 pm
. . . In my book a failure of the student reflects upon the teacher. In this animated graph http://www.bom.gov.au/climate/enso/sub-surf_anim.gif the rapid temperature changes over several hundred meters in a few days shows me the effect of circulation overwhelming that of conduction. 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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Nice graphic. Thermal diffusivity (turbulent) is precisely what is used to describe time averages over these vertical transports of heat for periods of months or more rather than weeks. I don’t think that God himself understands turbulence. The best we can do is a phenomenological mixing length theory to describe conduction, viscosity and diffusion in the presence of turbulence, but average thermal diffusivity provides a good parameterization of the vertical transport of heat in the oceans. Temperature profiles from surface to great depths, averaged over a few months, can be well described in terms of an average thermal diffusivity.
On longer time scales of decades to multiple decades, horizontal thermohaline circulation is what transports cold water from polar regions into the depths at lower latitudes. That is what makes the thermocline a stable feature of the tropical to mid-latitude oceans (aside from seasonal variations near the surface). The ocean depths are still cold, in part, because of the cold water runoff from the melting ice during the most recent deglaciation. There were times in the geologic past when the earth was warmer, polar ice was lacking and the ocean basins were filled with much warmer water. Many people make the mistake of thinking that our climate is some optimal and stable feature of the earth, but it is not. The earth has spent at least 90% of the last million years locked in ice ages and we are about due for another one.
bones says:
October 10, 2013 at 10:27 pm
Temperature profiles from surface to great depths, averaged over a few months, can be well described in terms of an average thermal diffusivity.
Fair enough, but then I’m puzzled by “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.
temperatures measured where?
at the surface.