This is an audio version of the Chapter 15 titled "Earth's Atmosphere", Section 4 "" in the CK12 Earth Science for Middle School Book by Authors Jean Brainard Ph.D. and Julie Sandeen created and used under the Creative Common Attribution/Non-Commercial/Share Alike 3.0 Unported (CC-by_NC-SA) License (http://creativecommons.org/licenses/by-nc-sa/3.0/). Don't forget to say thanks at http://www.ck-12.org/saythanks/ - See more at: http://www.teachertube.com/video/154-ck12-earth-science-for-middle-school-air-movement-413416#sthash.rR5PeoGj.dpuf
