GEOG 1040H Lecture Notes - Lecture 4: Ice Crystals, Cyclogenesis, Advection
Document Summary
Absolute humidity: weight of water vapour per volume of air (kg m^-3) Index is temperature independent: warmer air tends to have a smaller absolute humidity then cold air. Specific humidity: mass of water vapour per unit mass of air. If your parcel of air is colder, its going to be denser and is going to want to sink. *always should know if the parcel of air is colder or warmer and the surrounding air. Clouds and fog: vapour pressure over a water droplet is bigger than the vapour pressure over an ice crystal. Fog - condensation that has occurred at ground surface. Advection fog cold air moving over warm water. Valley fog at night the air at the mountain top cools, the cooling produces condensation. Atmospheric lifting mechanisms: convergent lifting, convection lifting, orographic lifting, cooling and condensation causes large amounts of precipitation, dry air wont produce precipitation, frontal lifting (cold and warm fronts, warm air is less dense.
