Which type of atmospheric pressure system is associated with clear skies and calm weather?

High-pressure systems are typically associated with clear skies and calm weather conditions. These systems occur when air descends in the atmosphere, which inhibits the formation of clouds. As the air sinks, it warms and dries, leading to fewer clouds and stable weather patterns. The presence of high pressure creates a sort of "lid" that prevents atmospheric disturbances that can lead to rain or storms, making these systems ideal for predicting pleasant weather.

In contrast, low-pressure systems are generally connected with cloudy skies and precipitation due to rising air that cools, resulting in condensation and cloud formation. Subtropical pressure and equatorial pressure systems can vary in their weather impacts, but they do not guarantee clear, calm weather in the same reliable way that high-pressure systems do. Therefore, the association of high-pressure systems with clear skies and calm weather is a foundational concept in meteorology.