radiative (solar-volcanic) forcing. The purple line shows the CO2 concentration (right axis). b, Shown are the global mean temperature (red), and the global mean precipitation intensity (blue) simulated in the forced run with the ECHO-G model. (p.p.m., parts per million.)
From the University of Hawaii ‑ SOEST, more modeling mania for the future.
New research shows complexity of global warming
Greenhouse gases versus solar heating
Global warming from greenhouse gases affects rainfall patterns in the world differently than that from solar heating, according to a study by an international team of scientists in the January 31 issue of Nature. Using computer model simulations, the scientists, led by Jian Liu (Chinese Academy of Sciences) and Bin Wang (International Pacific Research Center, University of Hawaii at Manoa), showed that global rainfall has increased less over the present-day warming period than during the Medieval Warm Period, even though temperatures are higher today than they were then.
The team examined global precipitation changes over the last millennium and future projection to the end of 21st century, comparing natural changes from solar heating and volcanism with changes from man-made greenhouse gas emissions. Using an atmosphere-ocean coupled climate model that simulates realistically both past and present-day climate conditions, the scientists found that for every degree rise in global temperature, the global rainfall rate since the Industrial Revolution has increased less by about 40% than during past warming phases of the earth.
Why does warming from solar heating and from greenhouse gases have such different effects on global precipitation?
“Our climate model simulations show that this difference results from different sea surface temperature patterns. When warming is due to increased greenhouse gases, the gradient of sea surface temperature (SST) across the tropical Pacific weakens, but when it is due to increased solar radiation, the gradient increases. For the same average global surface temperature increase, the weaker SST gradient produces less rainfall, especially over tropical land,” says co-author Bin Wang, professor of meteorology.
But why does warming from greenhouse gases and from solar heating affect the tropical Pacific SST gradient differently?
“Adding long-wave absorbers, that is heat-trapping greenhouse gases, to the atmosphere decreases the usual temperature difference between the surface and the top of the atmosphere, making the atmosphere more stable,” explains lead-author Jian Liu. “The increased atmospheric stability weakens the trade winds, resulting in stronger warming in the eastern than the western Pacific, thus reducing the usual SST gradient—a situation similar to El Niño.”
Solar radiation, on the other hand, heats the earth’s surface, increasing the usual temperature difference between the surface and the top of the atmosphere without weakening the trade winds. The result is that heating warms the western Pacific, while the eastern Pacific remains cool from the usual ocean upwelling.
“While during past global warming from solar heating the steeper tropical east-west SST pattern has won out, we suggest that with future warming from greenhouse gases, the weaker gradient and smaller increase in yearly rainfall rate will win out,” concludes Wang.
Citation:
Jian Liu, Bin Wang, Mark A. Cane, So-Young Yim, and June-Yi Lee: Divergent global precipitation changes induced by natural versus anthropogenic forcing. Nature, 493 (7434), 656-659; DOI: 10.1038/nature11784.
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Full paper here: http://www.readcube.com/articles/10.1038/nature11784
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What is the wavelength of a photon?
Box of Rocks says:
February 1, 2013 at 2:38 pm
What is the wavelength of a photon?
It ranges from 10000 m for radio waves to 10^-16 m for gamma rays.
Google “electromagnetic spectrum”.
Box of Rocks says:
February 1, 2013 at 2:38 pm
What is the wavelength of a photon?
###
wavelengeth = planksConstant * C / photonEnergy
Next questions…
So when a molecule of say CO2 bumps into a molecule of N2 what determines the net transfer of energy and how is accomplished?
Also, if I have 2 molecules 1 of CO2 and one of N2 and the are at say 100 degree F and they just happen to be caught in an up draft and are lifted vertically.
What happens and how is there energy transferred?
If by chance the air is still, and then sun sets, and the atmosphere ‘cools’ (the molecules have not moved) what happens in that case?
Why and how are the cases different?
Where does the energy go?
DesertYote:
Does the energy that say CO2 molecule absorbs = photonEnergy?
or is the energy transfer in and out of the molecule non-linear?
And why?
John Marshall:
“The sun is the ONLY heat input into the climate system.”
No, the core of the planet generates heat that travels outwards. The heat comes from four sources:
– Residual heat from the gravitation formation of the planet.
– Heat from radioactive elements decaying in the core and mantle.
– Gravitational friction as the solid core is pulled by the Moon and to a lesser extent the sun and planets.
– Losses from the earth’s electromagnetic system.
There are poor measurements of the heat flux. Parts of the USA have fluxes up to 10Wm-2. Average continental USA flux is estimated at about 250mWm-2 but it is poorly understood what the flux is in other parts of the planet, especially under the oceans.
It is also not known how the flux varies with time.
Volcanism is a forcing in the system, but it is very poorly quantified.
Box of Rocks
February 1, 2013 at 5:12 pm
The total momentum ( mass * velocity as classically defined, there are other defs) of a system is constant. That means that the sum of the momentum of two particles after they interact is the same as it was before they did so, and is independent of the nature of the interaction. Mathematically, momentum is an invariant.
Box of Rocks says:
February 1, 2013 at 5:12 pm
The following may help:
http://wattsupwiththat.com/2011/05/07/visualizing-the-greenhouse-effect-light-and-heat/
DesertYote, doesn’t that apply to a totally inelastic collision?
What happens to the energy if the collision is non linear?
Can that be backed up with math?
“Steven Mosher says:
February 1, 2013 at 8:20 am”
And here’s me thinking the science of the climate system on this rock was settled (Read understood and not simulated).
Box of Rocks says:
February 1, 2013 at 8:47 pm
DesertYote, doesn’t that apply to a totally inelastic collision?
Momentum is always conserved in collisions, whether elastic or inelastic. But kinetic energy (1/2mv^2) is only conserved in elastic collisions which we are dealing with in molecular collisions. To test this, note that you cannot hear molecules colliding in a glass jug nor do the molecules warm up due to their collisions. This proves that no energy lost.
P.S. To my earlier reply, I also should have added:
http://wattsupwiththat.com/2011/03/29/visualizing-the-greenhouse-effect-molecules-and-photons/
Box of Rocks says:
February 1, 2013 at 8:47 pm
DesertYote, doesn’t that apply to a totally inelastic collision?
What happens to the energy if the collision is non linear?
Can that be backed up with math?
###
Velocity is a vector so elastic collision is just simple addition of vectors.
Different branches of mechanics have different ways of defining momentum, but they all play the same role, though quantum mechanics is a bit of an outlier. The mathematical foundations of all of this can get a bit complicated and a proper study would entail a fairly detailed tour of modern math. Don’t forget that much of mathematics was developed as a language to express the rules of mechanics as relieved through experimentation.
Werner Brozek says: February 1, 2013 at 9:57 pm
“….note that you cannot hear molecules colliding in a glass jug…”
Well, not entering the argument here…just pointing out that there are all sorts of wavelengths our ears cannot detect….
Lew Skannen says:
February 1, 2013 at 2:42 am
No! Not complex at all. David Attenborough explains it.
Basically the climate is modelled by a green line and a yellow line. The green line is the climate without human produced CO2 and that is a rather trivial model because all it requires is the input of volcanoes and the sun … and a few hundred other parameters available here.
You then add in the effect of CO2 to this simple model and you get the yellow line.
Simple.
—————————————————————————————————————
If you then look at Keith Briffa`s tree ring study there is a divergence from the dodgy ground temps around 1960, so the model in the above video shows temps not increasing from 1960 which agree with Briffa`s tree rings, has there actually been a temp rise or is it it all down to those dodgy UHI infected numbers. It seems to me that the tree ring proxy`s may be correct after all.
http://s446.beta.photobucket.com/user/bobclive/media/attenborough_zps1fdbe055.jpg.html?sort=6&o=0
http://s446.beta.photobucket.com/user/bobclive/media/800px-Briffa-tree_ring_density_vs_temperature_1880-2000_zps39423dee.jpg.html?sort=6&o=1
in some sciences you cannot afford the test and you cannot control the test conditions.
So, you have a choice:
1. head in the sand. we know nothing.
2. Our best reasoning ( modelling ) says the following.
Folks interested in live fire can see this
http://jaspo.csd.disa.mil/archives.html
As an engineer, modeling the structural performance of an aircraft is cake walk. I can have 3rd year Mechanical Engineering Students design and test aircraft structures till the chickens come home to roost.
Modeling a non linear thermodynamic model of the earth is far more complex task.
“..global rainfall has increased less over the present-day warming period than during the Medieval Warm Period, even though temperatures are higher today than they were then.”
The first clause is a pretty good falsification of the second clause an vice versa.
The absorbed Photons raise the energy level of their respective molecules (symbolized by red outlines).
The energized molecules re-emit the Photons in random directions, some upwards, some downwards, and some sideways. Some of the re-emitted Photons make their way out to Space and their energy is lost there, others back down to the Surface where their energy is absorbed, further heating the Earth, and others travel through the Atmosphere for a random distance until they encounter another GHG molecule.
So when a ‘new’ photon is emitted as the CO2 molecule loses energy – what wavelength is emitted, why and how do we know?
John Marshall says:
February 1, 2013 at 2:54 am
Global warming by GHGs does not require additional heat input; it is a matter of redistribution of the heat; the troposphere warms, the stratosphere cools. (The ocean is involved, too, but I’m trying to keep this simple.) I’m sure you’d answer this by saying that re-radiation is bunk, but if it is bunk, it is bunk regardless of whether the sun is the only heat input, so it would only make sense to point out the latter if you were arguing that global warming, regardless of mechanism, without additional heat input is impossible – but in that case your argument would be grossly inadequate because surely it is conceivable that something could redistribute the heat. The bottom line is that your argument fails with no consideration of the science at all; merely pointing out that global warming theory claims that the warming is a matter of redistribution suffices to kill it as a rebuttal to that theory.
So Mosh, the extension of your argument seems to say that if a model shows there is risk walking on the sidewalk, we should all be made to suit up in padding to protect us in case we fall and in addition, pay a “potential injury tax” for the sidewalk.
Actually, the risk of sidewalk injury is FAR greater than the risk of injury from climate change. So there ya go greenies who are so concerned about what harm we are doing to our children. Make us pay an injury tax on sidewalks.
Leif Svalgaard says:
February 1, 2013 at 1:31 pm
Vuk: Beauty is in the eye of the beholder
Dr.S: So is, apparently, garbage.
best with ‘full screen’ setting
There still seems to be some lingering doubts about the greenhouse effect (GHE). The GHE is not new; it has been known about, measured, and accounted for in engineering calculations for decades. Although it wasn’t commonly called the greenhouse effect until recently, as I recall we just referred to it as the radiation from the “apparent sky temperature”.
Heat Transfer (lol, literally: Energy Transfer Transfer) in a nutshell is the transfer of energy through a variety of mechanisms/processes including conduction, convection, and radiation.
In a wordy equation format:
[Net Energy Gain] = [Energy In] – [Energy Out] = [Solar (Short Wave) Energy Absorbed] – [Long Wave Energy Emitted] + [Long Wave “backradiation”] – [Evaporation] ± [Convection] ± [Conduction]
Solar (Short Wave) Energy Absorbed = the energy from the sun. Important variables are TSI, location (angle), sky conditions (clear/cloudy), and albedo.
Long Wave Energy Emitted = the energy radiated in proportion to its temperature (Stephan-Boltzmann). Important variables include temperature and emissivity.
Long Wave “Backradiation” = the greenhouse effect. Important variables include sky conditions (clear/cloudy) and relative humidity.
Evaporation = Energy evaporating water (typically). Important variables include mass and heat of vaporization.
Convection = Energy transferred through convection. Important variables include mass, velocity, thermal conductivity, heat capacity, and temperature gradient.
Conduction = Energy transferred through conduction. Important variables include thermal conductivity, mass, heat capacity, and temperature gradient.
If we were just looking at “heat gain” at night of an outside surface it would most likely be negative, therefore, we might look at Heat Loss instead (so it would be positive) and furthermore if we just looked at the radiant part:
[Net Radiant Heat Loss] = [Long Wave Energy Emitted] – [Long Wave “Backradiation” (GHE)]
http://www.asterism.org/tutorials/tut37%20Radiative%20Cooling.pdf
Note that clouds and water vapor regulate the magnitude of the GHE.
So John how does one account for the energy that is absorbed by CO2 then re-emitted at a different temperature?
Since only GHG gases i.e. CO2 can absorb that particular energy, what happens to it? Yes one has to account for it in a thermodynamic equation yet the sad reality is that that energy is lost forever.
There is a lot of energy that is out there that is not used for anything yet it is there,
How does one account for it?
John West says, February 2, 2013 at 2:46 pm: “There still seems to be some lingering doubts about the greenhouse effect (GHE). The GHE is not new; it has been known about, measured, and accounted for in engineering calculations for decades. … In a wordy equation format:
[Net Energy Gain] = [Energy In] – [Energy Out] = [Solar (Short Wave) Energy Absorbed] – [Long Wave Energy Emitted] + [Long Wave “backradiation”] – [Evaporation] ± [Convection] ± [Conduction]”
==========================================================
John, let me guess for how many decades: ZERO? Because I never heard about that “back radiation warming” being proved experimentally.
To your equation, there are some problems there.
First, why would you cut out Solar Infra-red (long wave)?? As we know from the Wood’s experiment, he needed an extra glass pane to eliminate the effect of solar infra-red there: “When exposed to sunlight the temperature rose gradually to 65 oC., the enclosure covered with the salt plate keeping a little ahead of the other, owing to the fact that it transmitted the longer waves from the sun, which were stopped by the glass. In order to eliminate this action the sunlight was first passed through a glass plate. There was now scarcely a difference of one degree between the temperatures of the two enclosures. The maximum temperature reached was about 55 oC.”. You can see, the solar IR was responsible for the 10C difference in temperature. Is it negligible to you? And the “greenhouse gases” do block some portion of the incoming solar IR, thus contributing to cooling. So,we have on the one hand cooling “greenhouse gases”. I just wonder, why we do not find any mention of it in the innumerable warmists’ explanations, neither in the IPCC reports nor in Wikipedia nor in other similar resources. It seems to be a dirty little secret to me, sorry.
Second, that thing about back radiation warming has apparently never been experimentally proven to work in the real world, although the hypothesis is 150 years old. On the other hand, the experiment by American professor of physics R.W.Wood dealt with the issue and demonstrated that the warming effect was either zero or negligible “even under the most favourable conditions” (http://www.wmconnolley.org.uk/sci/wood_rw.1909.html).
Does not look good for the AGW concept.
Box of Rocks says:
”So John how does one account for the energy that is absorbed by CO2 then re-emitted at a different temperature?”
Energy doesn’t have a temperature.
”Since only GHG gases i.e. CO2 can absorb that particular energy, what happens to it? Yes one has to account for it in a thermodynamic equation yet the sad reality is that that energy is lost forever.”
Once a CO2 molecule absorbs some energy that energy becomes vibration energy in the molecule (not translational therefore not affecting temperature within a gas), from there it could be emitted as IR or through a collision with another molecule become translational motion which is encompassed in the temperature measurement of a gas.
”There is a lot of energy that is out there that is not used for anything yet it is there,
How does one account for it?”
One accounts for it with the LAW of conservation of mass and energy.
Greg House says:
”John, let me guess for how many decades: ZERO?
Absolutely not zero. This is from memory because I don’t feel like crawling around my cold attic digging through boxes but way back in the 1980’s my “Heat Transfer, A Numerical Approach” had an equation for estimating radiant heat loss for a outside body at night that basically went [replacing engineering symbols for words]:
[Net Radiant Heat Loss] = [Stephan-Boltzmann Constant] X [Emissivity] X [Temperature(body)^4 – Temperature(sky)^4]
That Temperature(sky) is the apparent sky temperature being subtracted from the body’s temperature to account for “backradiation” or GHE in order to estimate the NET radiation instead of just the body’s emission based on its temperature alone. There are more accurate ways, like the link in my previous post shows, but this would do in most situations.
”First, why would you cut out Solar Infra-red (long wave)??”
You’re right there is significant IR in solar output, but solar spectrum peaks at a shorter wavelength and that’s pretty much what everyone identifies it by. I don’t think it really matters at night when there’s no solar UV or IR or anything in between.
CO2 absolutely can be a cooling agent (besides adsorbing solar IR), take a scenario where convection has heated some gas with CO2 in it, some of that energy could be imparted through collision to a CO2 molecule which them might emit that energy as IR resulting in net cooling of the mass of gas.
Experimentally, go outside at night and point an infrared thermometer at the darkest part of the sky you can find, the temperature read out will be the temperature proportional to the IR the instrument is picking up, i.e. apparent sky temperature.
Notice that while the GHE is real, it’s just one little part of the overall heat transfer scheme of things.