Air Masses and Weather Fronts Lesson 5
What is an air mass?
United States’ Air Masses (Page 49)
What happens when air masses meet? The boundary between air masses is called a . There are 4 types and they can be found on page: 63 in your Catastrophic Events Book (Only 3) 222 in your ScienceSaurus (All 4 with symbols) Animations can be found on the following link: http://www.phschool.com/atschool/phsciexp/active_art/weather_fronts/
What happens when air masses rise or sink? When a “warmer” air mass is rising you have low atmospheric (barometric) pressure. This is represented by a red L on a weather map. When a “cooler” air mass is sinking you have a higher atmospheric (barometric) pressure. This is represented by a blue H on a weather map.
What makes the wind blow? When a cooler sinking air mass rushes in to take the place of a warmer rising air mass we get wind. Wind almost always goes from a higher pressure H area to a lower pressure L area.