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Moderator
Location: Graham, North Carolina | Hey All;
Actually this is a change to the OT direction I took Andre's thread "Moncktons Calculations", my apologies Andre. Charles, John and Alastair have all been very patient with me, as I tried to wrap my mind around the basic physical processes and unlearn a false concept I had picked up recently in regards to how different gases can be combined into the same container and the pressure not be changed. (The concept was, that it was possible that the density could be changed and with a corresponding increase in temperature, though the air pressure remained the same. As John and others pointed out if the temperature increases so would the apparent density decrease. This appears to fit with the theory that along with the concept that for a given temperature the density of a gas or an amalgam of a mix of gases would have a specific density and to to change any of the four values will change the nature of the others. (Mix, Temperature, Density, Pressure))
In short, the BS I had read was wrong and the result is I got into an extended OT discussion as I tried to get things straightened out in my mind. To the end of trying to clear up my understanding I decided to take the correct concept out for a walk to see if I can understand the macro effects of the physical processes in light of the actual weather. This has led to the following attempt at the hypothetical activities that would occur under the corrected concepts and may be verified by recent observations.
Hey Charles;
Again thanks for your input. What you have written recently suggests to me is that the atmosphere must be similar to a pot on the stove with a light cover. You can heat the contents until the liquid begins to change state. The lid begins to compress the contents and the internal temperature increases in the forming vapor until the pressure is sufficient and the lid pops up and removes a portion of the pressure.
The difference in the atmosphere is that gravity appears to form a heavy lid and the pot is oversized, a poor conductor and on a much too small burner. Instead of popping up the lid, you have rapid turnover of the atmosphere. It would appear that the majority of the exchange of energy would occur at the edges of cooler/warmer air parcels. So even though you get more vapor in the air over the liquid you should also be getting much higher turnover, which is in line with the hurricane intensity hypothesis of Global Warming.
The problem is that much of the energy would appear to be lost in the convection through the layers of the atmosphere rather then the winds in many of the recent tropical storms. This ends up resulting in lower pressure zones and increases in secondary wall eyes; however, much of the added energy is lost by the time it returns to the surface, as it disperses with as much outflow as inflow to the storms heart which seems to cool the waters and warms the upper atmosphere, in advance of the storm. This appears to dissipate much of the additional surface heat before the storm arrives. This appears to result in a stronger anti-cyclonic zone in advance of the storm and can result in the increase in upper atmospheric wind shear resulting in a horizontal distribution of the upward convective forces and hence the loss of the pressure differential required to drive the storm as would be expected when dealing with the temperature differential between the warmer SSTs and the relatively cooler upper troposphere.
Apparently this translates into an additional branch of physics which were had not discussed before in relation to the energy change of the atmosphere, the dynamics of wind as it disperses the additional surface heat. The suggestion would be if there were a direct relationship between global surface temperature increase and any other natural physical process it should be wind, if all other parts of the equation were to remain the same, as is observed everyday.
If there is a direct correlation between wind and temperature then we have the means to measure the amount of actual surface heating that must be occurring in relation to the increased surface heating. If the average wind is driven by the flow of heat and the resulting barometric pressure zones we might need to go a bit further and discuss the reasons or the theories regarding the formation of stagnant pressure zones. How do they form and why would they disconnect from the Jet Stream? Does the Jet Stream develop a tighter gradient in a warming environment and increase it's meander through the sky instead? Hence, the question now becomes one of whether or not the change in the Jet Stream could have a direct correlation to surface temperature changes as well? Which then leads to another thought what drives the Jet Stream anyway and what effect does it have on the ENSO, NPO (aka PDO) and NAO?
The result suggests that there should be a relationship between the surface winds, the temperature differentials based on altitude and the average wind speeds, along with the resulting ocean current speed or volume increases. Anyone wish to discuss? If not, it is not an issue, I figure that the rightness of this thought pattern suggests we will probably be back here in just a few years as more data is collected.
This is terrible so much work and so little time, hopefully, the world will end up taking care of itself, in the meantime it is a lot of fun trying to understand...
Dave |
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| Anytime you can disperse energy, the T is going down. Anytime there is T!=0 there is radiation leaving. |
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| ldavidcooke - 14/12/2007 13:39 Hey All; Actually this is a change to the OT direction I took Andre's thread "Moncktons Calculations", my apologies Andre. Charles, John and Alastair have all been very patient with me, as I tried to wrap my mind around the basic physical processes and unlearn a false concept I had picked up recently in regards to how different gases can be combined into the same container and the pressure not be changed. I think what you needed was Dalton's law of partial pressures (which I have never really understood so kept quiet) but ... Water vapour is not an ideal gas. Steam (gaseous water) is. But don't confuse the water aerosol that you can see coming out of the spout of a kettle with steam. Steam, and water vapour, are a colourless gas which is not visible. HTH, Cheers, Alastair. |
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| Alastair,
Don't you mean water vapor is an ideal gas like steam versus water aerosol is not? Of course no real molecule or atom is an ideal gas but they come fairly close in atmospheric conditions to being reasonably well described as one.
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| No, steam is gaseous water and behaves like an ideal gas provided that it is kept at temperatures above 100 C. If you lower the temperature, and you are now talking about water vapour, then its partial pressure falls according to its saturated vapour pressure not proportionally to the absolute temperature which an ideal gas does. Putting it another way, as you increase the temperature of water from 0 C to 100 C the vapour pressure of water rises from approximately 0% to 100% exponentially. The pressure of a ideal gas rises in proportion to the absolute temeperature ie 275 K to 373 K. Therefore, as you raise the sea surface temperature the amount of water vapour in the air rises exponentially. The positive feedback from the additional greenhouse effect that is caused has the potential to produce a runaway temperature rise. |
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Moderator
Location: Graham, North Carolina | Hey Alastair;
Thanks, I had reviewed the Dalton partial pressures and that was the driver of the steam experiment I had suggested in the other thread. I believe that if the environment was maintained at 100 Deg. C that the physics appears to be different for the physics of vapor versus steam.
However, as the original issue relates to Charles suggesting the vapor density/mass would lessen, it would fall under the Dalton partial principle, in my understanding. If the steam vapor was used for the model, it appears the physics actually more relate to the unified ideal gas principles. This is one of the quandaries I keep running into as I try to understand the physics. Both you and Charles have been very patient and it is appreciated.
Dave
Got it flip, flopped, now corrected, if I follow correctly...
Edited by ldavidcooke 20/12/2007 09:00
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| I see what you're saying but usually when one speaks of ideal gases, it's in the context of theory and concepts. It's a good approximation for most of the atmosphere too. Water vapor is a gas and behaves much like the ideal gas until conditions are changed and it ceases to be in the vapor form or some reservoir of non vaporous h2o comes into play.
As for the feedback, it would seem that more vapor means more lighter density air which will convect upward. Once aloft, it will reach temperatures where cloud formation will prevail. Clouds will block incomming solar flux, reducing surface insolation, evaporation and cloud formation. Sorta sounds like an iris doesn't it?
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| ldavidcooke - 20/12/2007 13:56 Hey Alastair; Thanks, I had reviewed the Dalton partial pressures and that was the driver of the steam experiment I had suggested in the other thread. I believe that if the environment was maintained at 100 Deg. C that the physics appears to be different for the physics of vapor versus steam. However, as the original issue relates to Charles suggesting the vapor density/mass would lessen, it would fall under the Dalton partial principle, in my understanding. If the steam vapor was used for the model, it appears the physics actually more relate to the unified ideal gas principles. This is one of the quandaries I keep running into as I try to understand the physics. Both you and Charles have been very patient and it is appreciated. Dave Got it flip, flopped, now corrected, if I follow correctly... The atmospheric pressure at the surface depends on the weight of air above that point. If you add water vapour at the base by heating the surface water then the pressure will rise, and it will lift the column of air above it. the air at the top of the column will spill off the top and so the pressure at the base will fall again. In other words the pressure at the surface remains constant but the density of air is reduced and convection results. I mention that because I have been told that convection is more often the result of chemical change rather than heating. In fact the area where the surface temperature is highest, the sub-tropical deserts, is where the air is descending rather than rising. The main areas of convection are in the tropics where the greatest humidities are found. |
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| cba - 20/12/2007 14:01 I see what you're saying but usually when one speaks of ideal gases, it's in the context of theory and concepts. It's a good approximation for most of the atmosphere too. Water vapor is a gas and behaves much like the ideal gas until conditions are changed and it ceases to be in the vapor form or some reservoir of non vaporous h2o comes into play. It certainly behaves like an ideal gas (in the boundary layer) until it stops behaving like an ideal gas (in the free troposphere.) Rather like There Was a Little Girl There was a little girl,
Who had a little curl,
Right in the middle of her forehead.
When she was good,
She was very good indeed,
But when she was bad she was horrid.
-- Henry Wadsworth Longfellow As for the feedback, it would seem that more vapor means more lighter density air which will convect upward. Once aloft, it will reach temperatures where cloud formation will prevail. Clouds will block incomming solar flux, reducing surface insolation, evaporation and cloud formation. Sorta sounds like an iris doesn't it? Your description of the feedback effect of clouds is close, but that is not how the Iris Effect works! First, cloud do not just cutreflect solar energy, they also radiate long wave radiation to space and to the ground. The radiation to space helps to cool the planet but the radiation to the ground tends to keep the surface warm. The Iris Effect is supposed to work by reducing the the radiation back to Earth and allowing more radiation to escape to space. This would act like a steam valve allowing heat to escape when teh temperature rose too high. However, if this effect does happen how is it that the cliamte in the past has been much warmer than it is today. Even during the last interglacial it was at least 2 K warmer. Why didn't the Iris kick in then?
Lindzen is correct that the models have not been proved correct. In fact they are continually being proved wrong but the programmers will not admit that there is a bug in their program. Spencer et al (2007) is a recent example of this, and RealClimate's response typical of how the scientists will not acept that their paradigm is wrong.
But both Lindzen and Spencer are arguing that the models are over estimating the effects from increasing CO2. In fact the models are underestimating the effects, as is shown by the rapid melt of the Arctic sea ice. |
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Logic Models - A Learning Moment
