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Post by glc on Sept 14, 2010 18:01:52 GMT
nautonnier It's not an argument. It's a dumb statement. The statement is correct but it doesn't add anything to the discussion. You know it's true. But you also know that I and glc know that it is true. So it's just a distraction. That's why it's dumb. Dumber still was glc saying the earth doesn't cool by convection. Dumber still was glc saying the earth doesn't cool by convectionIt depends what you mean by "the earth". Do tell us what you mean.
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Post by magellan on Sept 14, 2010 21:56:44 GMT
Dumber still was glc saying the earth doesn't cool by convection. Dumber still was glc saying the earth doesn't cool by convectionIt depends what you mean by "the earth". Do tell us what you mean. I don't know, you tell use what you mean..... solarcycle24com.proboards.com/index.cgi?action=display&board=globalwarming&thread=1179&page=18#47693glc said You seem to be implying that the earth can cool by convection. It can't. The earth (and ocean) surface can cool by convection (and evaporation) but that just moves the heat elsewhere (e.g. the poles). It doesn't cool the system. You think you were right, but didn't support it with anything substantive. You said: Magellan
I was right - you didn't understand - again.
Would you like to have a go at it again? Maybe reword it? You said the system cannot be cooled by convection. I beg to differ. BTW glc, your track record is quite dismal. This will add to it. Was that blur glc back pedaling at Olympic speeds? Whoosh.....there he goes!
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Post by northsphinx on Sept 14, 2010 22:16:11 GMT
"We find that volcanoes play a particularly important part in the phasing of the multidecadal variability through their direct influence on tropical sea-surface temperatures, on the leading mode of northern-hemisphere atmosphere circulation and on the Atlantic thermohaline circulation. We suggest that the implications of our findings for decadal climate prediction are twofold: because volcanic eruptions cannot be predicted a decade in advance, longer-term climate predictability may prove challenging, whereas the systematic post-eruption changes in ocean and atmosphere may hold promise for shorter-term climate prediction." www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo955.html
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Post by glc on Sept 14, 2010 22:36:41 GMT
I don't know, you tell use what you mean.....
I mean the earth's climate system (or the troposphere) which can only cool by radiation from the top of the atmosphere. The climate system does not cool by convection.
Now tell us what you mean .....
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Post by magellan on Sept 14, 2010 23:07:30 GMT
I don't know, you tell use what you mean.....I mean the earth's climate system (or the troposphere) which can only cool by radiation from the top of the atmosphere. The climate system does not cool by convection. Now tell us what you mean ..... Yes, the back pedaling begins.... Let's try again. You said: It doesn't cool the system. What evidence do you have that supports your contention that convection can't and doesn't cool the system? Will you now redefine what the system is? Is the system now limited to the top of the atmosphere? Do you think Spencer and Lindzen would agree? In that other thread, you said: The earth (and ocean) surface can cool by convection Just so we can nail down your definition of climate system, what does it include and exclude? What is 'radiative-convective equilibrium'?
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Post by glc on Sept 14, 2010 23:34:52 GMT
What evidence do you have that supports your contention that convection can't and doesn't cool the system? Will you now redefine what the system is? Is the system now limited to the top of the atmosphere? Do you think Spencer and Lindzen would agree? The 'system' is effectively confined by the tropopause. The amount of energy in the 'system' is determined by the incoming solar energy and the outgoing LWIR energy. If incoming=outgoing the system will have a stable temperature If incoming < outgoing the system will cool If incoming > outgoing the system will warm Adding ghgs to the atmosphere reduces the outgoing radiation to space so that incoming is greater than outgoing and the system warms. Yes I do think Lindzen and Spencer will agree with me. I also think that you are getting confused. Convection cools the earth's surface but this just transfers heat vertically. It doesn't remove it from the atmosphere. It is the radiation balance at the TOA which determines whether we warm or cool (or neither). UPDATE: I was right you are getting confused. You say What is 'radiative-convective equilibrium'? You've got this from Roy Spencer's blog but you haven't understood what he's saying. The full paragraph reads what many people don’t realize is that the 33 deg. C of surface warming is not actually a measure of the greenhouse warming – it represents the balance between TWO competing effects: a greenhouse warming effect of about 60 deg. C (the so-called “pure radiative equilibrium” case), and a convective cooling effect of about 30 deg. C. When these two are combined, we get the real-world observed “radiative-convective equilibrium” case. Spencer is talking specifically about surface warming.
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Post by magellan on Sept 14, 2010 23:51:57 GMT
What evidence do you have that supports your contention that convection can't and doesn't cool the system? Will you now redefine what the system is? Is the system now limited to the top of the atmosphere? Do you think Spencer and Lindzen would agree? The 'system' is effectively confined by the tropopause. The amount of energy in the 'system' is determined by the incoming solar energy and the outgoing LWIR energy. If incoming=outgoing the system will have a stable temperature If incoming < outgoing the system will cool If incoming > outgoing the system will warm Adding ghgs to the atmosphere reduces the outgoing radiation to space so that incoming is greater than outgoing and the system warms. Yes I do think Lindzen and Spencer will agree with me. I also think that you are getting confused. Convection cools the earth's surface but this just transfers heat vertically. It doesn't remove it from the atmosphere. It is the radiation balance at the TOA which determines whether we warm or cool (or neither). What is 'radiative convective equilibrium'? You said convection cannot cool the system, so provide the evidence, either observationally or the meteorological literature. Every time you say someone is confused, you end up turning the conversation into a convoluted litany of babble talk once you figure out you're wrong. Now, again, what is 'radiative convective equilibrium'? If you can explain that, it will be arguing with yourself. Have at it.
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Post by glc on Sept 15, 2010 0:04:18 GMT
What is 'radiative convective equilibrium'? You said convection cannot cool the system, so provide the evidence, either observationally or the meteorological literature. Read my UPDATE in the previous post. The 'radiative convective equilibrium' in Spencer's post is referring to the earth's surface. Have a look at this for starters en.wikipedia.org/wiki/StratosphereThis should give you some idea why convection effectively stops at the troposphere. This vertical stratification, with warmer layers above and cooler layers below, makes the stratosphere dynamically stable: there is no regular convection and associated turbulence in this part of the atmosphere There is very little energy transfer between the troposphere and the stratosphere other than by radiation. Read this as well eosweb.larc.nasa.gov/EDDOCS/whatis.htmlLook at the Trenberth model of the atmosphere.
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Post by magellan on Sept 15, 2010 0:36:27 GMT
What is 'radiative convective equilibrium'? You said convection cannot cool the system, so provide the evidence, either observationally or the meteorological literature. Read my UPDATE in the previous post. The 'radiative convective equilibrium' in Spencer's post is referring to the earth's surface. Have a look at this for starters en.wikipedia.org/wiki/StratosphereThis should give you some idea why convection effectively stops at the troposphere. This vertical stratification, with warmer layers above and cooler layers below, makes the stratosphere dynamically stable: there is no regular convection and associated turbulence in this part of the atmosphere There is very little heat transfer between the troposphere and the stratosphere other than by radiation. Ah, so you now quote Spencer and then resort to Wikipedia to redirect your argument to minimize the significant error in your original statement which I quoted. You also tried to invoke Lindzen to support your hypothesis, but it was noted you never did cite any references To whit, you said: It doesn't cool the system.
That is what you said, period, end of story. So the system is not really a system, but only 2m above the surface? The surface is the system and convection only takes place there? Read Spencer's latest paper, then come back here and convince us convective cooling does not cool the system . www.drroyspencer.com/wp-content/uploads/Spencer-Braswell-JGR-2010.pdfLet's guess, you read it and found some errors
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Post by poitsplace on Sept 15, 2010 3:32:50 GMT
GLC is (to put it in easier to understand terms) a luke warmer that's supporting the luke warming impacts of CO2. I do point out occasionally that most of the reason he gets crap is because he's worded things poorly for this group...such is life. He agrees with you guys more than you think...and GENERALLY is debating the finer (and often not so fine) points frequently discussed here.
I think luke warmers and those specifically debating against catastrophic AGW all agree that...
From the tropopause on, radiative transfer is pretty much the only energy transfer to be concerned with (occasional overshoot by thunderstorms not withstanding).
Up to the tropopause the atmosphere establishes a radiative/convective equilibrium. Decreasing one necessarily increases the other.
The radiative/convective equilibrium shift keeps the temperature of the tropopause from getting TOO low and therefore limits the impact of CO2's forcing to some extent, but likely not entirely.
And finally...a doubling of CO2 might lead to around 1C increase in temperature. It might possibly be a little higher in the event that there are some positive feedbacks. OR it could possibly (probably) be less if feedbacks are negative.
Then of course the catastrophic AGW crowd all believe the various components of the earth's climate system were precariously balanced and likely to undergo catastrophic changes at the slightest hint of a change
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Post by glc on Sept 15, 2010 7:56:45 GMT
Magellan says this
Ah, so you now quote Spencer and then resort to Wikipedia to redirect your argument to minimize the significant error in your original statement which I quoted. You also tried to invoke Lindzen to support your hypothesis, but it was noted you never did cite any references
Poitsplace says
From the tropopause on, radiative transfer is pretty much the only energy transfer to be concerned with (occasional overshoot by thunderstorms not withstanding).
I said this
There is very little energy transfer between the troposphere and the stratosphere other than by radiation.
Poitsplace reckons I've worded things poorly. Perhaps he's right. It was 1:30am when I was responding to Magellan and I was trying to do something else at the time. Thank you, Poitsplace, if you have managed to clarify the issue.
Magellan
In the context of my previous posts the word 'system' refers to earth's weather/climate system which includes the land surface, oceans and the troposphere. Convection occurs within the troposphere but this just means the air is mixed at higher altitudes (and latitudes). The 'system', as a whole, does NOT cool by convection. It is only by emitting LW radiation to space that the earth can cool and maintain a balance with incoming solar energy.
Lindzen knows this. Spencer knows this. I know this, Poitsplace knows this and many others who post on this blog know it. I doubt it would be easy to find a paper by Lindzen or Spencer where this is specifically mentioned because, for most readers, it is a fundamental, well accepted fact. A bit like the fact that the earth orbits the sun.
I'll re-word my original statement just in case there is any ambiguity.
The earth's climate system, as a whole, does not cool by convection. The earth's climate system can only cool by radiation.
Now tell me which part you disagree with or don't understand.
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Post by steve on Sept 15, 2010 11:21:18 GMT
Magellan,
The best interpretation of your spat with glc is that you and glc are talking about different things. The way around it is for *you* to say what *you* mean so that glc can put what he is saying into context. Instead you focus on your erroneous assumption of what glc means with the quote-mined, context-free "It doesn't cool the system".
What Spencer appears to be saying is that a basic model would predict that the surface of the earth would be another 30C warmer if there were no convection. That doesn't falsify glc's statement that the convection does not remove energy from the earth system.
Tell us what *you* think, magellan.
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Post by hunterson on Sept 15, 2010 17:11:31 GMT
Convection, among other things, moves parcels of air up to where they can lose energy more easily.
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Post by socold on Sept 16, 2010 22:16:42 GMT
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Post by nautonnier on Sept 16, 2010 22:56:56 GMT
Well of course something else has been changing in the troposphere SoCold As atmospheric humidity drops the same heat content will result in rising atmospheric temperature as the dry air has a significantly lower enthalpy than humid air. Perhaps you should use heat content of the atmosphere for your last graph, as it is the correct metric for measuring trapped heat energy, and see if the same simple slope remains.
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