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But then you would lose the evaporation that is needed for this phenomenon to occur.

Evaporation could be replaced by any type diffusion in this system. I imagine a similar process could arise out of difference in salt concentration.

Edit: Updated to clarify the relationship between evaporation and diffusion.

It is a phase transition, it takes energy to evaporate because of the change in entropy/volume (from Clausius Clapeyron).

Weightlessness could give 3d with evaporation.