What primarily causes downslope winds to occur?

Downslope winds occur primarily due to air cooling and sinking. When the air cools, it becomes denser and begins to move downward due to gravity. This process is often enhanced by topographical features such as mountains or hills, where the cooler, denser air accumulates at higher altitudes and then flows downhill. As the air descends, it accelerates, leading to increased wind speeds on the lower slopes.

In this phenomenon, the cooling of the air can occur in various ways, including radiation cooling overnight or through the evaporation of moisture, both of which contribute to the process of creating a stable layer of cold air at the surface while warmer air remains aloft. This difference in temperature and density creates the conditions necessary for the air to flow downslope, resulting in the characteristic downslope winds observed in mountainous regions and during specific weather conditions.