What is the primary factor that affects the stability of air masses?

The primary factor that affects the stability of air masses is temperature differences between air layers. Stability in this context refers to the tendency of an air mass to resist vertical movement. When there is a significant difference in temperature between layers of air, stability can be influenced.

Warm air is usually less dense than cold air, so when warm air is found at the surface, it tends to rise. If the air above is cooler, this rising motion can continue, leading to unstable conditions and potential for convection and storm development. Conversely, if the air above is warmer than the air at the surface, this can create a stable layer that suppresses upward movement, leading to more stable atmospheric conditions.

This temperature profile can result from various factors, including solar heating, geographical features, and movement of weather fronts. Therefore, while moisture, wind speed, and geographical features can influence weather patterns and local conditions, they do not specifically focus on the inherent stability of the air mass in the same fundamental way as temperature differences do.