Two snowlines

[Tom Mazanec]

If a mountain could be high enough to reach the stratosphere, would it have a second snowline above which would be no snow, just bare rock?

[Hornblower]

If a mountain could be high enough to reach the stratosphere, would it have a second snowline above which would be no snow, just bare rock?

My educated guess is yes. In a thought exercise we could make the mountain arbitrarily high and put the summit above all precipitation. Clearly Mt. Everest is not that high. I don't know how much higher we could go and still have the bedrock able to bear the load.

[swampyankee]

The density of granite is about 3500 kg/m^3 and its compressive strength is about 200 MPa; the limiting height would be on the order of 50,000 meters. Basalt is roughly similar in its structural properties.

[Hornblower]

The density of granite is about 3500 kg/m^3 and its compressive strength is about 200 MPa; the limiting height would be on the order of 50,000 meters. Basalt is roughly similar in its structural properties.

That would be above about 99.9% of the atmosphere and virtually all of the water vapor. I would say definitely no snow up there.

[DaveC426913]

That would be above about 99.9% of the atmosphere and virtually all of the water vapor. I would say definitely no snow up there.

Hmph. Every image of Niven's Fist-of-God mountain on Ringworld got this completely wrong.

[Trebuchet]

My recollection is that it looked snowcapped but it was really exposed ring metal.

[grant hutchison]

Fist-of-God Mountain had grown large without coming near. Bigger than any asteroid, roughly conical, she had the look of a snow-capped mountain swollen to nightmare size.

Later ...

"But Fist-of-God is real, Louis."
"No, no, no. It's just a shell. Look down; what do you see?"
"Ringworld foundation material."
"We thought it was dirty ice when we first saw it. Dirty ice in hard vacuum! [...]"

Grant Hutchison

[profloater]

There have been icing incidents in high flights, way above normal vapour, it is supposed that tiny ice crystals could be elevated. So ice at hight altitude might be possible, the difficult issue is whether it could sublime away faster than it arrives. The transport mechanism might be charge and magnetic fields way higher than normal atmospherics. If for sf you imagine a grounded mountain and crystals charged by solar radiation, then a kind of sputtering could happen, it would look rather beautiful.

[glappkaeft]

Noctilucent clouds form at 80 km in the mesosphere and the amount of water vapor in the stratosphere is one of the factors that interacts with other factors to drive global warming. I don't know if there is enough moisture to cover the surface of a mountain but clearly there is some water up there.