What occurs to dry air as it descends on the leeward side of a mountain?

As air descends on the leeward side of a mountain, it undergoes a process known as adiabatic warming. When air rises over a mountain, it cools and can condense moisture, leading to precipitation on the windward side. However, as the air descends on the leeward side, it warms and the capacity of the air to hold moisture increases. This process does not involve the air actually absorbing additional moisture from the environment; instead, the warm air creates conditions that can lead to lower relative humidity. Therefore, the correct understanding is that dry air becomes more effective at keeping moisture in vapor form rather than in liquid, thus illustrating how descending air affects humidity levels.