Climate 101: Why is there snow on mountain tops?
Why is there snow on mountain tops was one of the very first questions that I asked my scientific mentor, Hans. It is indeed a difficult question. If say the summit of Mt Everest or Mt Blanc is nearer the Sun, surely these summits should be hot.
It seems illogical, especially in view of the one piece of pure Physics that I have proposed, namely that Radiation must encounter mass for heat to be generated. Inter alia.
Quite recently there was an enormous fire in a car park in Liverpool where some 1400 cars were destroyed. So hot was the fire that even the concrete floor of this multi storeyed building was decimated. It so happens that Liverpool is 70 miles away from the Isle of Man, where I am presently staying and this is a very similar distance
from the surface of our Planet to the edge of space, known as the Karman line. So did we feel the heat here in Douglas? No, not at all.
If we take a more modest example we know that if we have a bonfire in our garden and we are five feet away the heat may be so intense as to singe one’s hair, yet twenty feet away the heat is barely felt at all. So it is clear that the closer one is to the source of the conflagration the greater the experience of hotness.
Therefore the molecules at the top of the Thermosphere on the edge of space, closest to the Sun, provided that these molecules have mass, should be hot. And guess what, they are, and reckoned to be over 2,000 degrees centigrade.
Therefore it might follow that the Thermosphere is mighty hot, but the contrary is true. It is to all intents and purposes incredibly cold. How can this be so contradictory? How can we reconcile the fact that the molecules are so hot yet the rest is so cold?
The answer is fairly simple. The Thermosphere is vast and is largely empty, with very few molecules there. So the very few molecules may be intensely hot but they may be say 70 miles apart, separated by emptyness, virtual vacuum. So the few molecules may be extremely hot, but the overwhelming atmosphere is cold. Should a human stray there they would be burnt to a frazzle and frozen to death at one and the same time!
Now we live in the lowest level, that is the Troposphere, and at base of the Troposphere we know that the molecules that make up our air are most dense, that is at sea level. As we gain in altitude we say that the air gets thinner, by which we mean that the molecules get farther and farther apart. What is in this intermolecular space? This is a question that came upon me one day that so excited me that I had to ring one of my mentors urgently in order to get the answer.
To my great surprise I was told the answer. Nothing. There is nothing, absolutely nothing between the molecules of gases that make up our air. I was completely overwhelmed by the significance of what this learned gentleman said. Why? Because, if the molecules of our air are suspended in a vacuum, then we know already that only mass can get hot, and have a temperature, or a measure of hotness.
One cannot heat nothing, which is why Outer Space, strictly speaking, is neither hot nor cold – it has no temperature for there is nothing to get hot, nothing to have a temperature. Actually a sort of nominal temperature is applied, using the Kelvin scale that goes down to Absolute Zero, to take account of dust or debris that might stray there.
So now let us put this all together and try to answer why the summits of our tallest mountains are cold. I must tell you that these are my own surmises based on the principles I have gleaned from a number of scientific mentors who have taken my education in this area in hand. They may well turn round on me and say my surmises are not correct.
When we talk of temperature it is most always of atmospheric temperature. When we hear a Weather forecast, we are not told the temperature of the sea in the English Channel or the North Sea, nor the temperature of the soils in a given area, but the expected air temperature in a given area at 5 foot off the ground. And this is where the molecules are most dense and therefore most susceptible to being heated, either by radiation or by Conduction.
Now at altitude where the air is thinner, where the distance between molecules is greater, it follows that with an absence of mass, there is likewise an absence of heat that we call cold.
This all relates to Avogadro’s law. So though the mountains may be slightly nearer the Sun from an earthly point of view, from a Solar point of view with a distance of over 90 million miles, Mt Everest is just a pimple. However the lack of molecules must govern it’s temperature. Hence snow on tops of mountains. The atmosphere or the lack of molecules in the atmosphere causes the extreme cold.
Additionaly there are many other factors we should never forget, namely that we are hurtling round the Sun at over 66,000 miles an hour on an elliptical orbit, where our distance to that Sun has a variance of some 5 million miles. The winds are always changing, a huge factor, then there is pressure and gravity and evaporation. The whole climate business is enormously complex, designed by the Almighty powers that I will call Great Nature or the Great Life Force.
Night follows day and day follows night. The seasons follow inexorably. And for Mankind to seriously believe that they have a hand in this, or even to imagine that mankind could help or hinder in these Almighty processes is the height of vanity.
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Carl Brehmer
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“However the lack of molecules must govern it’s temperature. Hence snow on tops of mountains. The atmosphere or the lack of molecules in the atmosphere causes the extreme cold.”
The thermodynamic phenomenon in physics called “free expansion” falsifies your thesis.
Ascending air decreases in temperature with altitude because it cools adiabatically–it does “work” against its progressively lower pressure surroundings, which decreases it internal energy, i.e., thermal energy is transferred via “work” to its surroundings.
Temperature is directly proportional to matter’s “internal energy” which is quantified in joules/gm; it is quantified by mass not volume. Just doubling the volume that a kg of a gas is occupying will not change its temperature if its internal energy remains the same. In “free expansion”–the expansion of a gas into a vacuum–no “work” is done and therefore no change in temperature occurs.
Snow forms on snow-capped mountains not because the air is thinner, but rather because its temperature is sub-zero. Kilogram for kilogram the air at the top of a snow-capped mountain has less thermal energy than the air at the base of the mountain.
Weather balloon soundings show that at an altitude of ~11km the air stops cooling. This is because that is the altitude at which tropospheric air stops ascending–stops cooling adiabatically. Above this “tropopause” the air begins warming with altitude. In the absence of the aggressive air movement seen in the troposphere, the air in the stratosphere can assume the temperature profile one sees in large bodies of water–the cooler more dense matter sinks to the bottom.
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Hans Schreuder
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Thanks Carl. What is the reason that the atmosphere starts warming once above the Tropopause? Jerry offers an explanation above, but I am not sure that is correct. Air density at ground level density is said to be 1.225 kg/m3 and in the lower Stratosphere is reckoned to be less than 0.16 kg/m3, dropping to 0.0014 kg/m3 at the Stratopause, yet it keeps on warming. What is there to be warmed if the air is so thin?
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Hans Schreuder
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OOPS! Density at the Stratopause is said to be 0.016kg/m3, not the 0,16 mentioned earlier, sorry.
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jerry krause
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Hi Anthony,
In a comment to your recent essay, https://principia-scientific.com/baldness-the-greenhouse-gas-theory/, I had reviewed that which you had previously written: “So who are the real deniers? Who are the supporters of phony science? I ask you, whatever their faults—and all human beings have faults.” I did not complete your statement because I considered what followed distracted attention from “all human beings have faults”. In my previous comment I had written: “We are all at fault if we do not try to restrict our science to observation and to accurately define as we ponder and write.” What I did not clearly state was that this was my answer to your question: “Who are the supporters of phony science?”
I often turn to what R. C. Sutcliffe wrote in his book—Weather and Climate. I do this because I consider Sutcliffe to be without fault but because I consider he writes some good things better than I could write them. This beside the fact that he was a meteorologist and I am not.
The title of your present essay is: Climate 101: Why Is There Snow On Mountain Tops? While I do not know, but I assume you wrote this title and from time to time you do mention snow in the text. But you never mention that there is water vapor (molecules) in the air. And I know that without water molecules cold will never produce snow. So I turn to Sutcliffe to offer readers of your essay an alternative.
Sutcliffe, my meteorology mentor, wrote: “We generally say that the air can hold no more than a definite maximum amount of invisible gaseous water, more or less according as the temperature is high or low, but the statement is acceptable only with reservations. In the first place, the presence of air—that is the unpolluted mixture of pure permanent gases—has little to do with the process. It is the amount of vapour in the available space that matters, the number of molecules of H2O per cubic centimetre, and the presence of other gases is not directly relevant. In this respect, it might be more correct to say that the space and not the air is more or less saturated with vapour, but in meteorology insistence on this distinction would be quite unnatural and confusing.”
Hence, my mentor joins with those who do not consider that “intuitive knowledge keeps pace with accurate definition.” Which in a preface to the readers of Galileo’s book, Dialogues Concerning Two New Sciences, the publishers of this book stated was a common saying at that time.
But my mentor almost immediately, after okaying (condoning) the use of sloppy terminology, wrote: “However, in considering the physics of phase change the presence of the air is not always relevant.” And continues with something which I consider to be very right and essential for one’s intuitive knowledge. “When liquid water and gaseous vapour are present side by side one needs only to think of the exchange of molecules across the interface to have a clear mental image of evaporation and condensation going on continuously.” What I consider most important of this sentence is that Sutcliffe invites the reader to begin to imagine in what I term the mind’s eye. For Einstein has stated: “The true sign of intelligence is not knowledge but imagination.” and “Imagination is more important than knowledge.”
And Sutcliffe continued: “The molecules in the liquid are in incessant motion and a small proportion, moving more rapidly than the average, escape from the liquid surface by overcoming the inter-molecular force which binds the liquid together; in much the same way a rocket, given sufficient speed, will escape from the earth’s gravitational force. The warmer the liquid the greater the speed of the molecules and the greater the number which have the necessary escape velocity—the warmer the water the more rapid the evaporation. At the same time, any molecules from the vapor which penetrate the liquid surface are captured and condensation takes place, at a rate which depends on the vapour temperature and density—or the vapor pressure. The net effect of the two processes going on continuously is either condensation or evaporation and there is a state of balance when escape and capture are at the same rate: in this case, the air is just saturated with respect to the liquid surface.” In this last sentence Sutcliffe accurately defined in a reader’s imagination what air (space) saturated with water molecules (vapor) actually is. Equally important is the accurate dynamic image of the incessant motion of matter’s atoms and molecules is being planted in the imagination of the reader.
However, Anthony, when I read your essay an inaccurate image of a static matter (air, atmosphere), with no water molecules, is being planted in my imagination.
I stop here because this image of many, many, tiny particles with an incessant motion whose ‘vigor’ (speeds) increase with increasing temperature should never be diluted with any fundamentally different image. It is too easy to race on and forget what one has just seen in one’s mind’s eye.
Have a good day, Jerry
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jerry krause
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My statement: “I do this because I consider Sutcliffe to be without fault but because I consider he writes some good things better than I could write them.” need editing. At one time I thought it said what I intended but I finally see that it does not. It Should be:
I do not do this because I consider Sutcliffe to be without fault but because I consider he writes some good things better than I could write them.
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4TimesAYear
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“The title of your present essay is: Climate 101: Why Is There Snow On Mountain Tops? While I do not know, but I assume you wrote this title and from time to time you do mention snow in the text.”
You don’t know? We learned this in grade school. Btw, the water vapor is a given.
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jerry krause
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Hi 4Times,
I have read that some years ski resorts on mountain sides do not get enough snow on which to ski. So, water vapor is not always a given just because the atmosphere is cold. The topic was climate and too many seem to consider that an year’s weather at a given location departs great from the ‘climate’. But I expect that the temperature at the tops of mountains still might be considered cold.
Many places during winter, the cold comes after the snow storm because cold air cannot contain much water vapor to precipitate.
Have a good day, Jerry
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jerry krause
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Yes, 4Times, i am old and make mistakes but I am sure you can correct my mistakes so I will not bother doing do.
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jerry krause
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Hi Carl,
I am quite sure you know the temperature profile of the stratosphere is because this atmosphere is not adiabatic. It is being heated during the daytime by mechanisms in which oxygen molecules are first dissociated into oxygen atoms and these oxygen atoms react with other oxygen molecules to produce ozone molecules which are dissociated back to oxygen molecules and atoms by a the absorption of a different portion of solar radiation and the latter process cycles over and over during the day time, as well as the first mechanism continuing producing more oxygen atoms as oxygen atoms associate (react) with other oxygen atoms to produce oxygen molecule by other mechanisms (reactions), produce a warming (sensible heat) of the atmosphere. Maybe too detailed but it is what is actually understood (explained) to be occurring.
Have a good day, Jerry
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Rosco
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Hi Jerry.
Given it is acknowledged that the stratosphere “commences” at an altitude well above the highest mountains on Earth I fail to see why “the temperature profile of the stratosphere is because this atmosphere is not adiabatic” is relevant to why mountains have snow ?
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jerry krause
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Hi Rosco,
You are right the stratosphere is not relevant to mountain tops. But I addressed my comment to Carl because he had written: “the air in the stratosphere can assume the temperature profile one sees in large bodies of water–the cooler more dense matter sinks to the bottom.”
Some how my comment did not up where it should have. Maybe something about my age.
Have a good day, Jerry
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Rosco
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“Should a human stray there they would be burnt to a frazzle and frozen to death at one and the same time!”
“However the lack of molecules must govern it’s temperature. Hence snow on tops of mountains. The atmosphere or the lack of molecules in the atmosphere causes the extreme cold.”
Are you kidding ?
You seem to be advocating the “space is cold” nonsense – extreme lack of molecules equates to extreme cold.
The nonsense that something cools nearly instantly in a near vacuum is just that – nonsense.
Explain this – In my freezer ice sublimates and within a relatively short amount of time I cannot find ice cubes for my single malt. A whole tray can totally disappear in a fortnight.
My freezer maintains minus 20°C at normal sea level atmospheric pressure where the boiling temperature of water is 100°C.
At the top of Everest the atmospheric pressure is ~0.33 sea level atmospheric pressure and the boiling temperature of water is ~70°C.
During Summer the average temperature at the summit of Everest is higher than minus 20°C.
https://www.dropbox.com/s/zcl94bmsfu99141/Everest%20Summit%20Weather.png?dl=0
Why doesn’t the ice sublimate so rapidly that it becomes unclimbable ?
It is after all subject to high levels of solar radiation and ice and snow have high emissivities > 0.9 and approaching unity.
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Wally
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Say what? You ruin your single malt with ice?
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