How do mountain valleys create frost pockets?

In mountain ecosystems, frost pockets are created through the interaction of topography and nocturnal cooling, a process often associated with temperature inversions.

On clear nights, the ground surface loses heat rapidly through radiation, cooling the air in immediate contact with it. Because cold air is denser than warmer air, it flows downhill under the influence of gravity—a phenomenon known as a katabatic wind. In hilly or mountainous terrain, this cold, dense air drains from higher elevations and accumulates in low-lying areas, hollows, or valleys.12

These depressions become frost pockets because they lack effective aerial drainage, trapping the cold air and preventing it from mixing with the warmer air above. This results in a localized microclimate where temperatures remain significantly lower than on the surrounding slopes, making these areas subject to more frequent and intense frost.31