GEOG 131 Lecture Notes - Lecture 18: Rossby Wave, Stratus Cloud, Surface Weather Analysis
Document Summary
Air mass- body of air with uniform temperature and moisture characteristics: most abbreviated using two letters: Rst relates to moisture (c or m) Second relates to temperature (t or p: form in source regions (some named by this) An air mass is modi ed when it leaves the source region. Lifting air masses cool adiabatically by expansion (pressure only) to reach dew point temperatures. Fronts: boundary between two air masses, often site of rising motion and active weather, warmer air will be forced to rise, named for moving air mass with the leading edge marked by symbols, cold. Cold air moves and displaces warmer, moist air > warm air lifts. Intense precipitation: thunderstorms > cumulonimbus clouds, warm. Warm air moves and displaces colder air. Wednesday, october 11, 2017: stratus clouds, stationary. Neither air mass is displacing the other. Warm air overrides cold air, forming clouds and precipitation. Mid latitude cyclone- low pressure system traveling across the mid latitudes: life cycle.
