What defines the atmospheric pressure in a high-pressure system?

The defining characteristic of atmospheric pressure in a high-pressure system is associated with fair weather and descending air. In these systems, the air is usually sinking, which inhibits cloud formation and leads to clear skies. As the air descends, it warms up, further preventing the condensation of moisture, resulting in stable and pleasant weather conditions.

This mechanism contrasts with low-pressure systems, where rising air can lead to cooling and the formation of clouds and precipitation. In high-pressure areas, the descending motion suppresses convection currents and turbulence, contributing to the overall stability of the atmosphere. Hence, high-pressure systems are typically associated with calm and sunny weather, making the assertion that they lead to fair weather and descending air the correct interpretation of the phenomena associated with such systems.