Water density and other things on high gravity planets

[CosmicGamer]

For no reason I can put my finger on, I was pondering about a citizen of a high gravity world with a large amount of surface water and began to wonder what would be the effect of the gravity on the water density? How hard would it be to swim in it's water? How does the higher gravity effect evaporation, clouds, weather, and the general cycle of water? Or does temperature have a larger effect on the waters density, evaporation and the overall water cycle?

I know there are folks here with a lot more science knowledge than myself. What do you think?

 

[tjoneslo]

The biggest issue with the items you raise (water cycle, etc) would be the atmospheric density. A high gravity world generally would have more atmosphere. A denser atmosphere has a number of interesting effects. Winds (if the temperature's drive them) may be slower but more destructive. A denser atmosphere could hold more water, making storms stronger.

The big difference in a body of water would be the water pressure would increase more quickly with depth. While swimming at the surface you would notice little difference. But trying to dive underwater you would find the water pressure getting uncomfortable much more quickly.

 

[GypsyComet]

Water's density is not going to change very much. Water pressure on the other hand will rise faster at depth because it is due to the weight of the water above you.

Swimming in heavier gravity will take about the same amount of effort since the swimmer's body density relative to the water will also remain similar (unless you are denser than water, in which case stay on dry land). Maximum diving depths will be quite different, though, and nitrogen narcosis (the bends) will be harder and lengthier to avoid. Leave deep diving to the native life.

 

[whartung]

For no reason I can put my finger on, I was pondering about a citizen of a high gravity world with a large amount of surface water and began to wonder what would be the effect of the gravity on the water density? How hard would it be to swim in it's water? How does the higher gravity effect evaporation, clouds, weather, and the general cycle of water? Or does temperature have a larger effect on the waters density, evaporation and the overall water cycle?

I know there are folks here with a lot more science knowledge than myself. What do you think?

I don't think it matters, at least within reasonable limits.

Simply, liquids don't compress (witness hydraulics), so gravity per se won't affect the density of liquids.

That said, a boat from a normal G world will "weigh more" on the high G world, and thus will displace more liquid to float. And it may well affect the buoyancy of a person who would normally be able to swim, but now may struggle floating in water since they're heavier.

But those are impacts on the objects themselves due to gravity, not to the liquids.

 

[Enoki]

Of course, it would also depend on salinity and such. In fact, you could easily have world with even standard or light gravity where the water is so salty that you can almost walk on it.

 

[warwizard]

I don't think it matters, at least within reasonable limits.

Simply, liquids don't compress (witness hydraulics), so gravity per se won't affect the density of liquids.

That said, a boat from a normal G world will "weigh more" on the high G world, and thus will displace more liquid to float. And it may well affect the buoyancy of a person who would normally be able to swim, but now may struggle floating in water since they're heavier.

But those are impacts on the objects themselves due to gravity, not to the liquids.

I think that the water ALSO weighs more, so there is no net effect on the boat. I would expect that 1.01 g/cm density fellow has to spend more energy to stick his face out of water to breathe, and the .99 g/cm density fellow spends less energy to do the same.
Edit, The effect on the boat comes from the atmosphere, the air has higher density so the displaced air aids the boat, which will ride a little higher esp. if the interior is kept at std. pressure.