logging in or signing up Unit 2 – Lesson 2 Air Masses and Fronts bsndev Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 3462 Category: Education License: All Rights Reserved Like it (5) Dislike it (2) Added: August 06, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Unit 2 – Lesson 2 : Unit 2 – Lesson 2 Air Masses and Fronts Air Masses : Air Masses A quick review!!!!!!!!!!!!!!!!!!!! Differences in air pressures cause air to move (winds) Air tends to move from areas of high pressure to areas of low pressure What is an air mass? : What is an air mass? (def.) A very large body of air that takes on characteristic temperature and moisture of a region Usually thousands of km in diameter Form over a source region with relatively stable conditions Air masses are named for their source region Types of Air Masses common in North America : Types of Air Masses common in North America Polar source region (colder air mass) (P) Tropical source region (warmer air mass) (T) Maritime source region (air mass forms over the ocean) (m) Continental source region (air mass forms over land) (c) Slide 6: As you can see from this map, air masses are named for their source or sources. There are many different types of air masses that direct the weather patterns in the United States. What is a Front? : What is a Front? In the world of weather, a front forms when two unlike air masses meet (cold and warm air masses) Can cause weather changes There are different types of fronts This unit will study only warm and cold fronts Cold Front : Cold Front Cold air moves in to replace warmer air Warmer air, if moist, will form large cumulus and cumulonimbus clouds (the thunderstorm kind!!) Usually cold fronts cause short-lived, violent storms Temperature decreases after the front moves through an area Represented with blue line with triangles Warm Front : Warm Front Warm air mass moves into replace a colder air mass Longer process to lift the colder, more dense air Clouds (much thinner, not puffy) form far ahead of the warm front Clouds near the base of the warm front are called STRATUS clouds These clouds are lower to the surface Usually cause lighter precipitation; longer in duration Represented on weather maps by a red line with red semi-circles Conclusion : Conclusion This lesson taught about air masses and fronts. An air mass is very large body of air (usually thousands of miles) that takes on characteristic temperature and moisture of a region Fronts form when air masses of different temperature and moisture collide The learning activities will further explain these topics! You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.