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Air Masses and Fronts (Sec. 14.2 ). - Roll of Air Pressure: i. Air masses - definition, description, classification, properties, types ii. Fronts - definition, description, 4-types, associated weather change
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AirMassesandFronts(Sec. 14.2 ) - Roll of Air Pressure: i. Air masses - definition, description, classification, properties, types ii. Fronts - definition, description, 4-types, associated weather change iii. Interaction between Fronts and Masses
Air Masses An air mass is a large body of air with generally uniform temperature and humidity. Air masses are named according to their "source region". - Polar latitudes - between 60° and the poles. - Continental - ever large land masses between 25° and 60°. - Maritime - located over oceans between 25° and 60°. - Tropical latitude - usually within 25° of the equator Air masses can control the weather for fairly long periods of times.
http://www.classzone.com/books/earth_science/terc/content/visualizations/es2002/es2002page01.cfm?chapter_no=visualizationhttp://www.classzone.com/books/earth_science/terc/content/visualizations/es2002/es2002page01.cfm?chapter_no=visualization Types of Fronts Fronts are the boundaries between two air masses. They are classified by which type of front is replacing another front. Warm Fronts: a warm front forms when a warm air mass moves into an area formerly covered by cooler air. Warm fronts always have a typical cloud series form –remember “CCAN” Cirrus -hair like, wispy Cirrostratus –wispy layers Altostratus –mid layers Nimbostratus –rain-bearing layers
Cold Front: a cold front forms when cold, dense air moves into an area occupied by warmer air. **Cold fronts have a steep angle whereas warm fronts have a shallow angle to them **
Stationary Front: These occur when the boundary between the warm and cold air masses remains fairly still for quite a while. While the weather is stable. it is usually cloudy and wet. Occluded Front: These form when a cold front overtakes a warm front.