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Post by Ratty on Sept 21, 2017 23:10:28 GMT
Acidohm, my understanding from Nautonnier's post on the other thread is that the "images of hurricanes" are showing temperatures at the top of the the clouds and therefore the cloud heights. They do not indicate the amount of IR. Fair enough Dwayne, I clearly missed the point at some stage! I wonder does this NASA page help at all? A Lesson in Infrared Light - Looking at Three Tropical Cyclones
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Post by icefisher on Sept 22, 2017 0:17:39 GMT
Well climate science attributes very little net heat being convected into the atmosphere. Its possible that is based upon the idea that the release of latent heat is at a Planckian rate and thus all it can do is correct for nighttime cooling of the atmosphere back to the standard lapse rate (other such overly simple assumptions are made in climate models as to begin to address other issues leaves more for the warmists to explain).
Water vapor having a double heat capacity changes the lapse rate in the atmosphere leaving it warmer than if there was no water vapor convecting. Hurricanes driving the moisture higher in the atmosphere leaves more heat high in the atmosphere than non-storm convection.
Since the cloud top radiation is very low because of being so high in the atmosphere and with the low emissivity of clouds hurricanes probably do not radiate a lot of heat immediately.
But as I recall Naut once saying heat moved into the atmosphere is simply heat on its way to space. I think that makes sense as once up there its not coming back down. Eventually that greater amount of heat left in the atmosphere and the fact the lapse rate is changed to even higher elevations, after the water vapor condenses and falls as rain is going to cool radiatively from greenhouse gases and the water remaining in the atmosphere.
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Post by missouriboy on Sept 22, 2017 1:27:35 GMT
Acidohm, my understanding from Nautonnier's post on the other thread is that the "images of hurricanes" are showing temperatures at the top of the the clouds and therefore the cloud heights. They do not indicate the amount of IR. Fair enough Dwayne, I clearly missed the point at some stage! For infrared, satellite instruments are measuring the intensity of IR radiation emitted by surfaces that pass through a specific atmospheric window ... for standard IR satellite imagery this wavelength is 10.7 microns. For non-cloud areas the surface is the land or ocean. For thick cloud areas the emitting surfaces are primarily within the cloud itself. Yes, high, thick cloud tops are cold ... but they are considered warmer than the surrounding, non-cloud air mass at similar elevation. which is not emitting in this wavelength, The IR is merely passing through from below.
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Post by missouriboy on Sept 23, 2017 15:00:28 GMT
This paper discusses different data and techniques for measuring cloud top elevation. These include Lidar, radar and infrared radiometers. It points out that the later technique may seriously underestimate this property because the measured infrared radiation was being emitted much deeper in the cloud structure. Another common way to measure cloud height uses measurements from nadir-viewing passive infrared radiometers. These instruments measure upwelling infrared radiance emitted from about one optical depth below the cloud top, and convert this to a cloud-top height. The most common way of converting radiance to cloud-top height is by finding the height in a nearby temperature profile where the environmental temperature equals the cloud-top brightness temperature, and assigning that height to the cloud top (for clouds with optical depths below one, more sophisticated methods, such as CO2 slicing [Wylie and Menzel, 1989], must be used). GLAS, on the other hand, detects a cloud top at the point where the optical depth, measured from the top of the cloud downward, exceeds an optical depth of 0.002 –0.02. Just as for radars, it has been assumed that these two levels are near each other for thick, convective clouds because of the high ice water content of deep convective clouds. However, case studies using aircraft data [e.g., Heymsfield et al., 1991; McGill et al., 2004] have shown that the one optical depth level can sometimes lie several kilometers below the lidar-detected cloud top,
and a recent study [Sherwood et al., 2004] found that this distance was typically 1 km even for deep convective clouds. www.researchgate.net/profile/James_Spinhirne/publication/252784274_Tropical_cloud-top_height_distributions_revealed_by_the_Ice_Cloud_and_Land_Elevation_Satellite_ICESatGeoscience_Laser_Altimeter_System_GLAS/links/5410e6590cf2df04e75d698d/Tropical-cloud-top-height-distributions-revealed-by-the-Ice-Cloud-and-Land-Elevation-Satellite-ICESat-Geoscience-Laser-Altimeter-System-GLAS.pdf
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Post by nautonnier on Sept 23, 2017 17:09:42 GMT
This paper discusses different data and techniques for measuring cloud top elevation. These include Lidar, radar and infrared radiometers. It points out that the later technique may seriously underestimate this property because the measured infrared radiation was being emitted much deeper in the cloud structure. Another common way to measure cloud height uses measurements from nadir-viewing passive infrared radiometers. These instruments measure upwelling infrared radiance emitted from about one optical depth below the cloud top, and convert this to a cloud-top height. The most common way of converting radiance to cloud-top height is by finding the height in a nearby temperature profile where the environmental temperature equals the cloud-top brightness temperature, and assigning that height to the cloud top (for clouds with optical depths below one, more sophisticated methods, such as CO2 slicing [Wylie and Menzel, 1989], must be used). GLAS, on the other hand, detects a cloud top at the point where the optical depth, measured from the top of the cloud downward, exceeds an optical depth of 0.002 –0.02. Just as for radars, it has been assumed that these two levels are near each other for thick, convective clouds because of the high ice water content of deep convective clouds. However, case studies using aircraft data [e.g., Heymsfield et al., 1991; McGill et al., 2004] have shown that the one optical depth level can sometimes lie several kilometers below the lidar-detected cloud top,
and a recent study [Sherwood et al., 2004] found that this distance was typically 1 km even for deep convective clouds. www.researchgate.net/profile/James_Spinhirne/publication/252784274_Tropical_cloud-top_height_distributions_revealed_by_the_Ice_Cloud_and_Land_Elevation_Satellite_ICESatGeoscience_Laser_Altimeter_System_GLAS/links/5410e6590cf2df04e75d698d/Tropical-cloud-top-height-distributions-revealed-by-the-Ice-Cloud-and-Land-Elevation-Satellite-ICESat-Geoscience-Laser-Altimeter-System-GLAS.pdfTypically radar sensed cloud tops can be up to 5000ft lower than the actual cloud top see this study from some time ago ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970027388.pdf. So that seems to match. Note that these areas that affect the real world flight safety are validated. Meteorological graphics from the GOES sensors not so much. The only testing appears to be algorithm and mathematics checking rather than real observational validation.
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Post by duwayne on Sept 23, 2017 17:31:40 GMT
I've provided a layman's description of latent heat which is based upon the observation that when water molecules condense, they heat up the surrounding air with heat equivalent to the latent heat. This is why we have thunderstorms and hurricanes and this can be shown in the laboratory (using glassware, of course).
Acidohm posted links to papers by Tatartchenko in which he convincingly shows that IR photons are given off when water condenses. Does that mean that my latent heat description is wrong?
I believe that my description of latent heat and Tatartchenko's statements concerning photon emissions are both correct.
How can that be?
I read through the Tatartchenko papers looking for anything which would indicate how much photon energy emission he finds as a percentage of the latent heat in the original water vapor molecule. If it's 100% obviously there is an indication that the latent heat is converted to photons on condensation.
I didn't find the answer I was looking for (although it may be there someplace) but I did find find a description of his hypothesized molecular physics and if I read it correctly, he says 2 to 4 photons are released when a molecule of water condenses.
Sigurdur has indicated that the energy in 1 IR photon is much less than the latent heat energy in 1 molecule of water. He didn't provide an exact value and I'd be interested if he is willing to do that, but let's just say that if the energy of 1 photon is one-millionth of the energy of the latent heat of condensation, and the photon energy comes out of the latent heat, then for all practical purposes my layman's description is correct.
If the above is true except that the photons do not come from the latent heat but come from energy related to changes in the bonds, then both statements above are totally true. I suspect that is the case.
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Post by sigurdur on Sept 23, 2017 18:33:35 GMT
Both are true. From my physics of a few stretched decades ago, my professor indicated that no photons are emitted via latent heat. It becomes sensible heat and then can be emitted as radiation. My memory is slightly tarnished by time, but the energy release was 1,000's of times more than the energy of a photon. I can no longer provide the math. Observation tho, using hydro cells to cool potatoes. The hotter the air temp being drawn in, the cooler the air temp being pulled out. All done via water changing phase.
For all practical purposes, a photon is an energy by-product of sensible heat.
Make sense?
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Post by sigurdur on Sept 23, 2017 18:39:33 GMT
As an aside, I am seasoned. I use stress ratings in steel frequently when I am building something. I use the latent properties of water. I don't remember the molecular reasons why things work, but I do remember how to use graphs, etc done by molecular folks to base decisions on.
I could teach them about soils, agronomy, marketing, stats which isn't their field of expertise. They don't know how I grow food, all they care about is the food in front of them.
Make sense?
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Post by nautonnier on Sept 24, 2017 14:43:58 GMT
As an aside, I am seasoned. I use stress ratings in steel frequently when I am building something. I use the latent properties of water. I don't remember the molecular reasons why things work, but I do remember how to use graphs, etc done by molecular folks to base decisions on. I could teach them about soils, agronomy, marketing, stats which isn't their field of expertise. They don't know how I grow food, all they care about is the food in front of them. Make sense? It makes sense Sig. People have been making use of latent heat for centuries. It is just disappointing when science seems content to hand-wave 'latent heat is released' and not make any attempt to explain either how so much energy can be 'stored' in a water molecule or how that energy is 'released' into the environment.
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Post by acidohm on Sept 24, 2017 15:04:34 GMT
Seeing as ir is being discussed here....
Chatting with a warmist, amongst their incorrectness they stated, all objects radiate heat.
The assumption was this was ir.
Now, objects in sunlight emit ir I'm sure...radiative heat right??
But then what about an object that radiates heat eg electric radiator.
Also, what about objects in for example, a deep cave?? With no energy input and no sun....
Obviously all objects above 0°k vibrate and therefore have capacity to heat via conduction/convection. The radiative bit has got me....
Edit: lol....spelt incorrect wrong 😝
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Post by duwayne on Sept 24, 2017 16:04:00 GMT
In a post above I made a comparison using the unsupported assumption that the latent heat energy in 1 molecule of water is a million times the energy of 1 IR photon. This would mean that if Tatartchenko is right and 2 to 4 photons are emitted when a water molecule condenses, then the energy of the photons emitted are insignificant.
I had hoped that someone would have found or calculated the actual ratio and posted it here since it would provide perspective on the latent heat condensation issue.
This morning I looked for a source for the value and couldn’t find one so I’ve made my own calculation. I came up with a number of 102,000,000 to 1 for the ratio of the energy of latent heat in 1 water vapor molecule to the energy of a photon. I knew the ratio would be high, but I wouldn’t have guessed it to be quite that high so I would encourage someone to check my calculation.
Here’s the bases for my calculation. I found an online reference which gave the energy value of 1 IR photon as 6.63 times 10 to the -34th Joules (6.63E-34). I haven't listed the reference since it would be good to corroborate that value.
I found a source which shows the heat of vaporization for water (which is the same as the latent heat of condensation) as 2260 Kilojoules per Kilogram. The problem then is to convert this value into the latent heat of condensation for 1 molecule of water and then into Joules so it can be compared directly with the photon.
Water vapor has a molecular weight of 18 so there are 18 grams of water in a Mol or dividing by 1000, 0.018 kilograms of water in a mol. Multiplying 0.018 Kilograms per Mol by 2260 Kilojoules per Kilogram (see above) we get 40.68 Kilojoules per Mol as the heat of condensation of water.
Since there are 6.02E+23 molecules in a Mol (Avogadro’s number), we divide that into 40.68 (see above) and we get 6.76E-23 Kilojoules as the heat of condensation for a molecule of water. Then dividing by 1000 we get 6.76E-26 Joules as the heat of condensation for a molecule of water.
Lastly, we divide the 6.76E-26 Joules, the heat (energy) of condensation of a molecule of water by 6.63E-34 Joules, the energy of an IR photon (see above) we get 1.02E+8 or 102,000,000 as the ratio of a water molecule’s latent heat energy of condensation to the energy of an IR photon.
Thank goodness for Excel because calculators don't help much with numbers of this size.
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Post by Ratty on Sept 24, 2017 23:23:24 GMT
Seeing as ir is being discussed here.... Chatting with a warmist, amongst their incorrectness they stated, all objects radiate heat. The assumption was this was ir. Now, objects in sunlight emit ir I'm sure...radiative heat right?? But then what about an object that radiates heat eg electric radiator. Also, what about objects in for example, a deep cave?? With no energy input and no sun.... Obviously all objects above 0°k vibrate and therefore have capacity to heat via conduction/convection. The radiative bit has got me.... Edit: lol.... spelt incorrect wrong 😝 Fail .... on two (2) counts !! First you MAKE the mistake, then you ADMIT it.
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Post by duwayne on Sept 21, 2019 16:47:44 GMT
Yesterday, I went to a ground-breaking ceremony at a college near where I grew up. The new building is an addition to the main science facility and the head science professors and top students were there to thank the donors. After the ceremonies, I got a chance to separately ask the head of the science department and a bright physics student about the molecular mechanics of latent heat.
In separate conversations they both gave me the same answer.
As liquids, the H2O molecules are bonded to each other. Considerable energy is required to free a water vapor molecule from its liquid neighbors. This energy is provided from the sensible heat in the liquid molecules which surround the “freed” water vapor molecule. The energy breaks the bonds but it is not actually taken away by the water vapor molecule.
On condensation, something similar to a chemical reaction occurs. The water vapor molecule bonds (reacts) with the liquid molecules and gives off heat which is captured by the liquid molecules as sensible heat.
I also talked to another student about "slow light". As we all know light (photons) travel at about 186,000 miles per second in air. She has found a material through which light travels at much slower speeds. Light can be shined onto a block of this material and the light will pass through, but it will takes a few seconds to do so.
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Post by nautonnier on Sept 21, 2019 20:44:44 GMT
Yesterday, I went to a ground-breaking ceremony at a college near where I grew up. The new building is an addition to the main science facility and the head science professors and top students were there to thank the donors. After the ceremonies, I got a chance to separately ask the head of the science department and a bright physics student about the molecular mechanics of latent heat. In separate conversations they both gave me the same answer. As liquids, the H2O molecules are bonded to each other. Considerable energy is required to free a water vapor molecule from its liquid neighbors. This energy is provided from the sensible heat in the liquid molecules which surround the “freed” water vapor molecule. The energy breaks the bonds but it is not actually taken away by the water vapor molecule. On condensation, something similar to a chemical reaction occurs. The water vapor molecule bonds (reacts) with the liquid molecules and gives off heat which is captured by the liquid molecules as sensible heat. I also talked to another student about "slow light". As we all know light (photons) travel at about 186,000 miles per second in air. She has found a material through which light travels at much slower speeds. Light can be shined onto a block of this material and the light will pass through, but it will takes a few seconds to do so. Honest I am not being argumentative I really want to know - but this seems like hand waving. So the first 'evaporation' the sensible heat 'frees' the evaporating molecule but it does not take away any heat.... So there is no such thing as evaporative cooling? The reason we sweat is to loose heat by evaporative cooling as the evaporating molecules remove the latent heat of evaporation. This is not true? Then the molecule that did not take any heat away, condenses and gives the heat it did not take away to the liquid molecules it condensed onto? It would be really really useful for someone to document the flow of latent heat and storage of latent heat without using words like provide, release, and even sensible heat(which is transference of heat from (somewhere in the molecule to somewhere in another molecule); but instead saying that the heat stored as (name how it is stored) is transferred to (heat sink) by (method of transference) where it is stored as (description of heat storage) or how the molecule loses heat that is how the storage for the heat transfers the heat from the molecule and the way it leaves the molecule.
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Post by icefisher on Sept 21, 2019 23:21:56 GMT
Honest I am not being argumentative I really want to know - but this seems like hand waving. So the first 'evaporation' the sensible heat 'frees' the evaporating molecule but it does not take away any heat.... So there is no such thing as evaporative cooling? The reason we sweat is to loose heat by evaporative cooling as the evaporating molecules remove the latent heat of evaporation. This is not true? Then the molecule that did not take any heat away, condenses and gives the heat it did not take away to the liquid molecules it condensed onto? It would be really really useful for someone to document the flow of latent heat and storage of latent heat without using words like provide, release, and even sensible heat(which is transference of heat from (somewhere in the molecule to somewhere in another molecule); but instead saying that the heat stored as (name how it is stored) is transferred to (heat sink) by (method of transference) where it is stored as (description of heat storage) or how the molecule loses heat that is how the storage for the heat transfers the heat from the molecule and the way it leaves the molecule. Not sure if these details matter. Trenberth's budget for the cooling of the surface and emissions to space holds that about 86 watts/m2 of heat is extracted from the surface into water vapor, transported to TOA and emitted to space. Beyond that only a net of about 18 watts/m2 each of radiation and conductive heat is extracted from the surface, absorbed by the atmosphere and eventually emitted to space. Thus latent heat accounts for about 70% of the surface cooling that involves the atmosphere. If you include the 40 watts/m2 emitted straight to space from the surface, then latent heat is still 53% of the overall surface cooling.
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