AlecM – the heated air molecules, they aren’t ejected, they just bump into their neighbors more frequently, thereby raising the pressure. The additional pressure expands the heated parcel of air thus reducing its density, then it rises as a thermal. This isn’t the only scenario, but it is a common one.
Comment on How long is the pause? by jim2
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Comment on Trenberth’s science communication interview by Wagathon
Nominally, it’s all about the Sun and albedo certainly plays a role in that. A study of the Earth’s albedo (project “Earthshine”) shows that the amount of reflected sunlight does not vary with increases in greenhouse gases. The “Earthshine” data shows that the Earth’s albedo fell up to 1997 and rose after 2001.
What was learned is that climate change is related to albedo, as a result of the change in the amount of energy from the sun that is absorbed by the Earth. For example, fewer clouds means less reflectivity which results in a warmer Earth. And, this happened through about 1998. Conversely, more clouds means greater reflectivity which results in a cooler Earth. And this happened after 1998.
It is logical to presume that changes in Earth’s albedo are due to increases and decreases in low cloud cover, which in turn is related to the climate change that we have observed during the 20th Century, including the present global cooling. However, we see that climate variability over the same period is not related to changes in atmospheric greenhouse gases.
Obviously, the amount of `climate forcing’ that may be due to changes in atmospheric greenhouse gases is either overstated or countervailing forces are at work that GCMs simply ignore. GCMs fail to account for changes in the Earth’s albedo. Accordingly, GCMs do not account for the effect that the Earth’s albedo has on the amount of solar energy that is absorbed by the Earth.
What we now know about the sun explains everything about late 20th century warming. As it turns out, “the modern Grand maximum (which occurred during solar cycles 19–23, i.e., 1950-2009),” says Ilya Usoskin, “was a rare or even unique event, in both magnitude and duration, in the past three millennia.” [Usoskin et al., Evidence for distinct modes of solar activity, A&A 562 (2014)]
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Comment on Trenberth’s science communication interview by Scott
african Warm Period had increased rainfall along the equatorial belt and lakes, rivers, grasslands and savannahs in the current Sahara desert. Saudi Arabia also in the Rub Al Khalai and Najuf deserts. So some may be wetter and some dryer.
Scott
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Comment on Trenberth’s science communication interview by Wagathon
ditto…
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by Pekka Pirilä
That H2O is a boson makes a difference only if a single state has an occupancy significantly different from zero. That’s not possible at high temperatures, because so many states are then available. Molecules in a lattice are also bound to their location so strongly that they do not switch place with their neighbors easily enough to make a difference.
The best known example of Bose-Einstein statistics is the superfluid helium at very low temperatures. Under those conditions all helium atoms are free to move in a finite volume and have a significant probability of having essentially zero kinetic energy. That’s a single state (or a set of very few states). Under those conditions the symmetry of the state relative to switching particles makes a big difference, and it’s this symmetry, what makes bosons to have B-E statistics.
I cannot imagine any conditions, where water molecules could have essentially zero kinetic energy and be free to move in a finite volume. When they are close to each other at very low temperature they are always in a molecular lattice.
Having very small differences between energies of states is not the same thing as having a very small total energy. Therefore I cannot see any situation, where many water molecules involved in cloud physics could share the same quantum state and make B-E statics significant for their behavior.
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by Carrick
It has been well known (since the 1930s!) that ordinary water has two nuclear spins, ortho-water (I=0) and para-water (I=1).
From <a href="http://en.wikipedia.org/wiki/Spin–statistics_theorem" rel="nofollow">the spin–statistics theorem,</a> we know that:
Integral spin = bosons.
Half integral spin = fermions.
That is all.
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by phatboy
Are you sneaking a peak?
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by Wagathon
<blockquote>In an annual global mean, about 80–90% of aerosol particles are removed from the atmosphere by in-cloud and below-cloud scavenging (wet deposition). Remaining part of particles is removed by different ways of dry deposition. (István Lagzi, et al., Atmospheric Chemistry, © 2013 Eötvös Loránd University)</blockquote>
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Comment on Week in review by brent
Kerry: God Wants Me to Save Muslim Countries from Global Warming
http://www.whitehousedossier.com/2014/09/03/kerry-god-save-muslim-countries-global-warming/
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by AK
@ Pekka Pirilä...<blockquote>Bosons are bosons and fermions are fermions. No more accounting of particles is needed for that.</blockquote>I find that hard to believe. When these <i>"Bosons"</i> are actually composite particles made up entirely of primitive Fermions. The question is whether the Fermion nature of these primitive particles can manifest itself when they are locked into configurations that are, for practical purposes, bosons.
For instance, the two electrons that work together to create a covalent bond are Fermions, but the union of those two electrons can, for some purposes, be considered a Boson. But not all purposes, or every atom would look like a helium or lithium atom.
@WebHubTelescope...<blockquote>Multiple photons can exist in the same state and therefore the Bose-Einstein statistics is important in deriving the Planck distribution. But not for physical matter such as water molecules, which obey the Pauli Exclusion principle and thus every molecule must exist in a different state.</blockquote>If it can happen with a helium atom, it can happen with a water molecule. The question is under what circumstances.
Now consider superconductors: in these materials, at the appropriate temperatures, a pair of electrons can be "attracted" to one another, occupying states identical except for opposing spins. The resulting particle behaves as a Boson.
For a long time, it was assumed that such phenomena required very low temperatures, however that <a href="http://en.wikipedia.org/wiki/High-temperature_superconductivity" rel="nofollow">assumption turned out to be overly simplistic</a>. It's <a href="http://www.simonsfoundation.org/quanta/20140430-decoding-the-secrets-of-superconductivity/" rel="nofollow">even possible</a> that <i>"room temperature superconductivity"</i> will become a fact.
Similarly, you shouldn't base a rejection of such possibilities regarding Bosons in cloud microphysics on obsolete and poorly understood <i>"rules of thumb"</i> you learned in graduate school.
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Comment on Trenberth’s science communication interview by Jim Owen
You quote Media Matters on Fox? I thought you were smarter than that.
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by AK
In an annual global mean, about 80–90% of aerosol particles are removed from the atmosphere by in-cloud and below-cloud scavenging [...]
But the key question is: how many times, on average, does a particular particle get to serve as a CCN?
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by Wagathon
The chemical composition of ‘a particle’ changes when dissolved in water…
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by Don Monfort
pair of fermions can behave as a boson
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Comment on Week in review by kim
Nope, stolen; God knows where.
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Comment on Trenberth’s science communication interview by Vaughan Pratt
As I have just recently judged a High School Science Fair,
“A critic is someone who never actually goes to the battle, yet who afterwards comes out shooting the wounded.”
–Tyne Daly
Rephrasing my (admittedly rudely phrased) claim, how does being asked to judge a high school science fair suddenly make you competent at something you were merely asked to judge, as opposed to do yourself?
That said, I’d be more than happy to be proved wrong by a set of slides for a talk you’ve given, on any topic.
I have to ask if you actually looked at it.
You say that as though anyone who looks at it would instantly see the truth of what you say.
Given that the panel was titled “Climate Change: It’s About the Data”, Judy’s 16 heavily technical graphs and a plug for the stadium wave seemed very much on point.
However given that the audience was the public, the conference schedule was enormously broad (music, gender equity, health, and dozens of other topics), and that she and Kevin were communicating in real time in a 15 minute window each, I would say Kevin’s talk was a better match to the audience, to the diversity of interests of the conference, and to the available constraints of real time.
If however you were comparing the two talks from the point of view of an audience of experienced climate science skeptics allowed to ponder each slide at leisure at home, I bet Judy would win hands down.
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by kim
Well, since plants like music it would be foolish of cows not to like music too. This is not dispositive; the odd cow won’t follow the herd.
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by Faustino
Geoff, Judith is married to an Australian and holidayed in Australia recently, she met a number of interested parties/organisations while she was here. Australian clouds are not unknown to here.
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Comment on Trenberth’s science communication interview by kim
Aimed at the uninformed masses, which he would manipulate as a demagogue, with fear, shame, and guilt.
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Comment on Thermodynamics, Kinetics and Microphysics of Clouds by kim
She really doesn’t know Aussie clouds at all.
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