What effect does lower atmospheric pressure have on evaporation rates?

Lower atmospheric pressure increases evaporation rates due to the reduction in the partial pressure of water vapor in the atmosphere. When the atmospheric pressure decreases, the ability of the air to hold moisture is diminished, enabling water molecules to escape from the liquid surface more easily. This process occurs because evaporation relies on the differences between the vapor pressure of water at the surface and the vapor pressure in the air above it.

As the atmospheric pressure drops, the gradient between the two vapor pressures widens, allowing for more water molecules to transition into the gaseous state. In addition, lower pressure can be associated with higher temperatures, which also contributes to increased kinetic energy among water molecules, further facilitating evaporation. This combination of lower pressure and potentially higher temperatures ultimately leads to higher evaporation rates.