so as water vapor increases, the density of air decreases. Temperature also changes the density of air. As air gets warmer it expands and becomes less dense, causing atmospheric pressure to fall.

On planets orbiting close to their respective suns, surface water evaporates into space. Planets in the box have the right atmospheric pressure and the right temperature to keep surface water in a ...

and condenses the water vapor into clouds, often resulting in rain. During the Atlantic hurricane season, forecasters often alert the public when atmospheric pressure over a region of the ocean ...

1643: Evangelista Torricelli conducts Berti's experiment with mercury instead of water. This leads to the invention of the barometer, which measures atmospheric pressure (a measure of the pressure ...

Parts of northern California could see up to a foot of rain, but Phoenix will remain dry and warmer than usual.