AVIA101 Lecture Notes - Lecture 21: Cool Air, Supercooling, Cirrostratus Cloud
Document Summary
Abundance of condensation nuclei: fog dissipates as the air temperature rises. Radiation fog: formed on cool, clear nights w/ high relative humidity, found in low lying areas. Advection fog: formed in coastal areas when warm, moist air moves over a cold land surface, fog does not dissipate with heat, rather it moves as wind direction changes. Steam fog: formed when cool air moves over warm water surfaces. Usually over rivers, small lakes: evaporation occurs which saturates the air. Frontal fog: forms during the passage of a warm front. Ice fog: forms on very cold days. Fog and mist: fog is less than 5/8 sm visibility (heavier than mist, mist is greater than or equal to 5/8 sm visibility. Mainly updrafts, this keeps moisture aloft and the size of precipitation grows. Water droplets become super cooled (pushed beyond freezing line) Downdrafts spread throughout the cloud: requirements.
