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At 14 C, the saturation vapor pressure of water is about 16 millibars. That's more or less independent of the total pressure--whether the total pressure is 1 bar or 50 bars it's the same. The boiling point is when the vapor pressure equals the atmospheric pressure, so if the atmospheric pressure was 50 bars, the boiling point would be around 300 C
Edit: not true Climate Realist. If water vapor is the only gas present, then the partial pressure equals the total pressure, but it could still be less than the saturation pressure, and the relative humidity would be less than 100%.
An example might clear this up. Imagine a planet like Earth, except with no atmosphere--you could imagine it's a giant tungsten sphere or something else with a low vapor pressure at ordinary temperatures. Maybe it's even at 14 C, like the question suggests. Now I dump out a bucket of water somewhere on that planet. At least some of the water will evaporate. Now I have an atmosphere--one that consists entirely of water vapor. You're claiming that the relative humidity of that atmosphere will be 100%, so if I were to dump out ANOTHER bucket of water, we would not expect it to evaporate--since the relative humidity is already 100%. I don't think so.
If water vapor were the only component of the atmosphere, the relative humidity would generally be 100%. More pressure from other gases would tend to lower relative humidity.
Pegminer
< If water vapor is the only gas present, then the partial pressure equals the total pressure, but it could still be less than the saturation pressure, and the relative humidity would be less than 100%.>
OK! Relative humidity could still be less than 100% if the vapor is not in contact with liquid water. The relative humidity could drop below 100% if the vapor undergoes isobaric heating, isothermal expansion or reversible adiabatic compression. (Not the only cases.)
C obviously doesn't read questions. The temperature in both cases are the same. Just different air pressure.
The air would be compressed but the water will not. You are correct that increased air pressure retards evaporation at the same temperature because the temperature at which water phase changes from liquid to gas is much higher.
Water cannot be compressed like air can. If one takes a fan and restricts the output of the air flow to nil the fan motor will be drawing max current because it is compressing the air before the point of restriction. If one were to take a water pump and restrict its output flow to nil the water pump will be operating at its peak efficiency. It will be drawing minimum current because there is no compression before the point of restriction so the impeller does not have to work as hard as it does when moving water. It's just spinning freely.
The interaction between air and water will be the same but the rate of the evaporation will be different in relation to the interaction because of the increased air pressure.
Clouds form when pressure drops so higher pressure more water, simple. See also the top of aircrafts wing the water droplets form when the pressure drops.
Saying cold air hols lees moisture is an old wives tale. When it is cold, molecules move slower but water vapor can be the same
Earths atmosphere is 1 bar and has an average temperature of 14 C. If the atmosphere were 50 bar would it hold more or less water at 14 C? Im thinking less because increased pressure prevents evaporation, but I want to be sure.
