Snow on the Hallelujah Mountains?

[Raiden]

Originally Posted by Ashen Key

....yes, but that doesn't answer the question. After all, you can ski in Hawaii. It's a question of altitude, not weather.

You are missing something.

Pandora is not a planet, it is a moon.

The fact that it is orbiting something that is also orbiting changes how often and how close the sun is in the sky. That, plus the high amount of Carbon Dioxide (the main reason why humans cannot breathe the air) creates what is essentially the ultimate greenhouse and squelches any chances for ice crystals to form in the atmosphere.

It is probably cooler up there, but if large reptiles (and therefore presumably cold blooded animals) like Ikran and Toruk are living up there in high numbers, it's gotta be pretty warm most of the time.

Okay, time for the plant person to step in.
IT's been established that the area where the movie takes place is the equivalent of a tropical jungle. What we saw in other areas (the plains and the coast) the plant diversity is very wide.
The plants on top of the floating mountains is different than the plants growing on the planet itself. There are likely micro climates on each individual floating rock as well and due to their floating and rotating, the climate changes constantly as well.
The flora at Site 26 seems to bear out a different weather pattern than on the ground. Long grass, different plant varieties that seem to indicate possible colder weather tolerance.
So, we'll have to see what Cameron plans for us in the next movie and perhaps in the novel as well.

Wow, so I'm not the only person that noticed this. w00t.

Yeah, the plants on top of the mountains were much different than the ones on the ground. There were very few trees, the dominant plants were either short, stubby shrubs or grasses, and a few of those cycad-like plants.

This happens because the atmosphere is thinner, and thus more damaging ultraviolet rays make it to the plants, which either stunts their growth or limits plant communities to only a few very hardy species. Wind and bad weather are also more severe at higher altitudes, so the plants are likely also subjected to more mechanical stress than the ones that grow in the jungle.

There is actually a place in venezuela that mimics this setting called the Tepui; mountains that are very high and very steep and are topped with plateaus that house small communities of life found nowhere else on Earth. There are few trees, and most plants are small and shrub like (depending on available moisture).

But no, I hihgly doubt the existence of much ice of any sort on Pandora.

[Banefull]

We had this exact same post on A-F. Thought I'd post what I came up with there on here also:

"Snow does not probrably exist on the mountains for a combination of reasons. First off, since this is a jungle, the air is full of moisture and water retains heat very well and releases it slowly, keeping the temperature rather constant (even at night). Next, a lot of foilage grows on the floating rocks which helps to absorb even more heat. Finally the atmosphere is very thick with clouds preventing a lot of heat from radiating into back into space. In the the scene where the valkyrie shuttle enters orbit we can clearly see some very very thick cloud formations blanketing the entire atmosphere as far as the eye can see. We also see lots of mist and cloud cover around the mountains themselves (remember Norm's comment that they cannot see anything after going VFR). All this = no snow.

Something that occurred to me was that Pandora orbits a giant gas giant. If I remember correctly, it enters into a dark phase for quite a while as it passes through the shadow of Polyphemus. Perhaps in the middle of this period we could see snow and ice formations at higher elevations. All depends on how well the environment can retain heat. Would be an interesting thing to know. I could easily imagine that during this time all the Ikrans would migrate away from their nests at the top of these mountains to the jungle canopy."

[Human No More]

Originally Posted by Zai-en-ken

It is probably cooler up there, but if large reptiles (and therefore presumably cold blooded animals) like Ikran and Toruk are living up there in high numbers, it's gotta be pretty warm most of the time.

I guess they would be endothermic because they aren't reptiles.




As for ice, there IS ice visible from space at the very north pole, but it's a small area.

[Raiden]

Originally Posted by Human No More

I guess they would be endothermic because they aren't reptiles.




As for ice, there IS ice visible from space at the very north pole, but it's a small area.

WTF?

If they aren't reptiles, then what the hell are they?

They have what look like scales (can be seen when Jake dismounts the Toruk @ the ToS), they have teeth, they lack beaks, they don't have hollow bones, they don't have feathers.........if anything they are Pandoran equivalents of Earth's ancient Pterosaurs.

[ISV Venture Star]

Pandora has lower gravity (0.8g) than the Earth. This means that the scale height (see link below)

Scale height - Wikipedia, the free encyclopedia

is greater. So you need to be at a higher altitude to see a big change in pressure (and also temperature) than is the case on Earth. Higher values of T would also increase H. OTOH, the Pandoran atmosphere has a fair amount of CO2, and that would mean that the average molecular mass (M) of the atmosphere is higher than on Earth, decreasing H. Hmmm.

[Ashen Key]

Originally Posted by Zai-en-ken

WTF?

If they aren't reptiles, then what the hell are they?

They have what look like scales (can be seen when Jake dismounts the Toruk @ the ToS), they have teeth, they lack beaks, they don't have hollow bones, they don't have feathers.........if anything they are Pandoran equivalents of Earth's ancient Pterosaurs.

We...don't know that they don't have hollow bones. And to be honest, I don't see how else they get up there if they DON'T have hollow bones. In addition, they are not from Earth, so they don't have the same species groups.

Originally Posted by ISV Venture Star

Pandora has lower gravity (0.8g) than the Earth. This means that the scale height (see link below)

Scale height - Wikipedia, the free encyclopedia

is greater. So you need to be at a higher altitude to see a big change in pressure (and also temperature) than is the case on Earth. Higher values of T would also increase H. OTOH, the Pandoran atmosphere has a fair amount of CO2, and that would mean that the average molecular mass (M) of the atmosphere is higher than on Earth, decreasing H. Hmmm.

...I always forget about the gravity thing. (Possibly because aside from Quaritch mentioning it, we don't see ANY effect of said lower gravity, *grumbles*). That makes sense.

[ISV Venture Star]

Have just found out that the lapse rate is what it's really all about.

Lapse rate - Wikipedia, the free encyclopedia

But again it relates linearly to gravity. Lower g, lower lapse rate.

[Patrice Maire]

I just read through my Survivalist guide for the first time and there are polar ice caps but another reason for no snow on the Thundering Rocks could also be the magnetic fields and their constant movement.
So, now that we've flogged this topic entirely to a squishy pulp on the ground....

[Human No More]

The magnetic fields would do nothing on their own... Movement COULD, I guess, but most remain in place.

[Banefull]

Magnetism does have some effects on water like reduced surface tension and it can cause snow to stick less to other surfaces in certain conditions but like human no more said above me, theres no real effect significant effect on snow formation.