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Post by duwayne on Jul 7, 2019 14:52:00 GMT
So, co2 is thought to warm our surface increasing the return of some IR bands back to it that would otherwise, at the speed of light, have exited our atmosphere to space. The effect of co2 on IR is 'scattering', the molecule in effect bounces the photons, in any random direction, some of which is down, some up...or wherever. My point is, the same bandwidths of IR are a component of TSI and, were it not for the presence of co2 in our atmosphere, have an un-impeeded route to our surface. Yet these photons too are subject to the same scattering effect of the co2 molecule and stand an equal chance of being bounced back to space as an earth originating photon does in being bounced back to earth. Which i suppose leaves any potential (probably negligible) warming influence to be a balance of the amount of earth generated relevent Ir bands in contrast to the quantities present in TSI. I have no idea what the figures are 🤷♂️ Acidohm, the key is that the TSI is almost all short-wave photons which cannot be absorbed by CO2. The earth emissions are mostly long wave photons and a small portion of these can be absorbed by CO2.
Also, the individual TSI photons contain about 20 times the energy of an earth photon and since the amount of incoming energy equals the amount of outgoing energy, there are 20 times as many earth photons leaving the earth’s atmosphere as TSI photons entering.
So with the earth’s photons greatly outnumbering the sun’s photons combined with the fact that the percentage of earth’s CO2-absorbable photons is far, far greater than the percentage of sunlight photons, the CO2 absorption of TSI is miniscule compared to the CO2 absorption of earth originated photons.
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Post by acidohm on Jul 8, 2019 16:57:19 GMT
The CO2 absorption of TSI is miniscule compared to the CO2 absorption of earth originated photons.
Thx Duwayne 👍👍
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Post by sigurdur on Jul 8, 2019 23:41:37 GMT
So, co2 is thought to warm our surface increasing the return of some IR bands back to it that would otherwise, at the speed of light, have exited our atmosphere to space. The effect of co2 on IR is 'scattering', the molecule in effect bounces the photons, in any random direction, some of which is down, some up...or wherever. My point is, the same bandwidths of IR are a component of TSI and, were it not for the presence of co2 in our atmosphere, have an un-impeeded route to our surface. Yet these photons too are subject to the same scattering effect of the co2 molecule and stand an equal chance of being bounced back to space as an earth originating photon does in being bounced back to earth. Which i suppose leaves any potential (probably negligible) warming influence to be a balance of the amount of earth generated relevent Ir bands in contrast to the quantities present in TSI. I have no idea what the figures are 🤷♂️ Acidohm, the key is that the TSI is almost all short-wave photons which cannot be absorbed by CO2. The earth emissions are mostly long wave photons and a small portion of these can be absorbed by CO2. Also, the individual TSI photons contain about 20 times the energy of an earth photon and since the amount of incoming energy equals the amount of outgoing energy, there are 20 times as many earth photons leaving the earth’s atmosphere as TSI photons entering. So with the earth’s photons greatly outnumbering the sun’s photons combined with the fact that the percentage of earth’s CO2-absorbable photons is far, far greater than the percentage of sunlight photons, the CO2 absorption of TSI is miniscule compared to the CO2 absorption of earth originated photons. The IR band is much larger than the CO2 portion.
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Post by walnut on Jul 11, 2019 19:45:00 GMT
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Post by Ratty on Jul 12, 2019 0:21:15 GMT
There is a link to the paper in that article; it's not obvious.
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Post by nautonnier on Aug 30, 2019 18:43:05 GMT
While not wishing to rekindle arguments on the 'release of latent heat' ..... From the article: "Christy compared the average model projections since 1979 to the most reliable observations — those made by satellites and weather balloons over the vast tropics. The result? In the upper levels of the lower atmosphere, the models predicted seven times as much warming as has been observed." This is the so called missing tropospheric 'hot spot' shown in _all_ the models. Now why would all the models show an increase in _temperature_ (a hot spot)? I believe that the reason is the assumption that has been often stated here that latent heat released by change of state of water is transferred to the other gases in the atmosphere as _sensible heat_ in other words when latent heat is released the surrounding atmosphere is heated up. This does happen (otherwise Dorian would not be 'barreling' (sic) this way now), but sensible heat transfer is not to the level the models expect as there is no hot spot. Now if a large proportion of the latent heat was radiated away as infrared (as shown by the satellites) there would be no temperature change as radiation is not heat, and there would be no hot spot which is what is shown by observation. I will cross post this to Temperature and CO2 to avoid thread drift here Any comments on the above hypothesis?
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Post by missouriboy on Aug 30, 2019 21:47:44 GMT
While not wishing to rekindle arguments on the 'release of latent heat' ..... From the article: "Christy compared the average model projections since 1979 to the most reliable observations — those made by satellites and weather balloons over the vast tropics. The result? In the upper levels of the lower atmosphere, the models predicted seven times as much warming as has been observed." This is the so called missing tropospheric 'hot spot' shown in _all_ the models. Now why would all the models show an increase in _temperature_ (a hot spot)? I believe that the reason is the assumption that has been often stated here that latent heat released by change of state of water is transferred to the other gases in the atmosphere as _sensible heat_ in other words when latent heat is released the surrounding atmosphere is heated up. This does happen (otherwise Dorian would not be 'barreling' (sic) this way now), but sensible heat transfer is not to the level the models expect as there is no hot spot. Now if a large proportion of the latent heat was radiated away as infrared (as shown by the satellites) there would be no temperature change as radiation is not heat, and there would be no hot spot which is what is shown by observation. I will cross post this to Temperature and CO2 to avoid thread drift here Any comments on the above hypothesis? As a non-physics sort, it sounds reasonable to me. So how do you test it? In the standard scientific way.
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Post by fatjohn1408 on Aug 31, 2019 1:27:59 GMT
While not wishing to rekindle arguments on the 'release of latent heat' ..... From the article: "Christy compared the average model projections since 1979 to the most reliable observations — those made by satellites and weather balloons over the vast tropics. The result? In the upper levels of the lower atmosphere, the models predicted seven times as much warming as has been observed." This is the so called missing tropospheric 'hot spot' shown in _all_ the models. Now why would all the models show an increase in _temperature_ (a hot spot)? I believe that the reason is the assumption that has been often stated here that latent heat released by change of state of water is transferred to the other gases in the atmosphere as _sensible heat_ in other words when latent heat is released the surrounding atmosphere is heated up. This does happen (otherwise Dorian would not be 'barreling' (sic) this way now), but sensible heat transfer is not to the level the models expect as there is no hot spot. Now if a large proportion of the latent heat was radiated away as infrared (as shown by the satellites) there would be no temperature change as radiation is not heat, and there would be no hot spot which is what is shown by observation. I will cross post this to Temperature and CO2 to avoid thread drift here Any comments on the above hypothesis? Not a physicist just an engineer. A hot blackbody radiates more than a cold one. Same goes for grey bodies off course (which are real life objects in reality. So just because you see a high radiation coming from a storm you cant say the latent heat is mainly converted in radiation. No it is transferred as heat and has succesfully heated up the clouds of the storm. Now that the clouds of the storm are hot it is radiating at a rapid pace in order to cool it down down to equilibrium temprlerature. And that is the radiative signature of the storm. I hope i made sense.
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Post by nautonnier on Aug 31, 2019 1:37:57 GMT
Any comments on the above hypothesis? Not a physicist just an engineer. A hot blackbody radiates more than a cold one. Same goes for grey bodies off course (which are real life objects in reality. So just because you see a high radiation coming from a storm you cant say the latent heat is mainly converted in radiation. No it is transferred as heat and has succesfully heated up the clouds of the storm. Now that the clouds of the storm are hot it is radiating at a rapid pace in order to cool it down down to equilibrium temprlerature. And that is the radiative signature of the storm. I hope i made sense. It makes sense and that is why all the models say that there is a tropospheric hot spot - except there isn't one. Remember the heat release is happening all the time due to the wet adiabatic lapse rate. One of the frustrations I have is that there is no good explanation for: ** How a water molecule holds such an extreme amount of energy ** How the water molecule releases that energy
There is a lot of hand-waving and ' it releases latent heat' is stated but I have seen no explanation of how. Even if it is by sensible heat - how is that done? The amount of heat involved is significant so how does that convert into kinetic energy of a colliding molecule of O 2 or N 2 as the water molecule in the middle of a water drop freezes into the ice crystal lattice?
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Post by acidohm on Sept 1, 2019 9:26:25 GMT
Not a physicist just an engineer. A hot blackbody radiates more than a cold one. Same goes for grey bodies off course (which are real life objects in reality. So just because you see a high radiation coming from a storm you cant say the latent heat is mainly converted in radiation. No it is transferred as heat and has succesfully heated up the clouds of the storm. Now that the clouds of the storm are hot it is radiating at a rapid pace in order to cool it down down to equilibrium temprlerature. And that is the radiative signature of the storm. I hope i made sense. It makes sense and that is why all the models say that there is a tropospheric hot spot - except there isn't one. Remember the heat release is happening all the time due to the wet adiabatic lapse rate. One of the frustrations I have is that there is no good explanation for: ** How a water molecule holds such an extreme amount of energy ** How the water molecule releases that energy
There is a lot of hand-waving and ' it releases latent heat' is stated but I have seen no explanation of how. Even if it is by sensible heat - how is that done? The amount of heat involved is significant so how does that convert into kinetic energy of a colliding molecule of O 2 or N 2 as the water molecule in the middle of a water drop freezes into the ice crystal lattice? I suspect i understand this conundrum less then yourself, but find it intriguing and feel compelled to understand it myself. Does this statement make any headway at all?? "Latent heat can be understood as energy in hidden form which is supplied or extracted to change the state of a substance without changing its temperature." Its the "hidden form" part which i think is the crux of the matter??
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Post by acidohm on Sept 1, 2019 9:44:48 GMT
As water boils, it takes the applied heat energy to convert liquid to gas, but remains at constant temperature for a period of time.
Where is the applied heat going during this time period??
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Post by acidohm on Sept 1, 2019 9:49:32 GMT
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Post by acidohm on Sept 1, 2019 9:57:56 GMT
Here is a decent look at bonds between water molecules. www1.lsbu.ac.uk/water/water_hydrogen_bonding.htmlWould it be incorrect to follow the line of inquiry that latent heat is an expression for the energy required to form/break these bonds during state change??
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Post by nautonnier on Sept 1, 2019 10:04:16 GMT
Here is a decent look at bonds between water molecules. www1.lsbu.ac.uk/water/water_hydrogen_bonding.htmlWould it be incorrect to follow the line of inquiry that latent heat is an expression for the energy required to form/break these bonds during state change?? I think you may be right. But as you will see everyone is far happier talking about applying heat to break bonds, but not as you say where this heat is going and how it stays 'stored' in a free water molecule to be released on condensation. It is not a trivial amount of heat either.
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Post by acidohm on Sept 1, 2019 10:11:43 GMT
Here is a decent look at bonds between water molecules. www1.lsbu.ac.uk/water/water_hydrogen_bonding.htmlWould it be incorrect to follow the line of inquiry that latent heat is an expression for the energy required to form/break these bonds during state change?? I think you may be right. But as you will see everyone is far happier talking about applying heat to break bonds, but not as you say where this heat is going and how it stays 'stored' in a free water molecule to be released on condensation. It is not a trivial amount of heat either. In my sorta proto understanding of this, i think stored is maybe the wrong way of describing it in relation to the molecule bonds. During phase change the molecules are taking or releasing the energy required to accomplish the bond requirements from the surrounding environment. Scanned through stuff to analyse water vapour, heres what we know. No bonds between vapour molecules Contain energy as they're excited Volumn in increase from liquid to vapour 1600x. So I'd assume the energy imbalance due to the condensation (and i mean that in terms of "to condense", ie, make small) a large volumn of excited molecules to a well bonded liquid form to be a net positive donation to the environment? Another way to look at it, the energy from all the molecules in 1.6m2 of are squeezed into 1cm2, and they dont need kinetic energy anymore because theyre bonded tightly to each other. (Tho obv not 1cm2 as a cloud isnt that dense.....)
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