1 / 21

Atmospheric Structure and Composition

Atmospheric Structure and Composition. Atmosphere: The thin envelope of gases surrounding the earth Highly compressible Density decreases rapidly with height Air: A mechanical mixture of gases and aerosols. Definitions. Vertical Structure of Atmosphere. Troposphere (surface to 8-20 km)

Anita
Download Presentation

Atmospheric Structure and Composition

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Atmospheric Structure and Composition

  2. Atmosphere:The thin envelope of gases surrounding the earth Highly compressible Density decreases rapidly with height Air:A mechanical mixture of gases and aerosols Definitions

  3. Vertical Structure of Atmosphere • Troposphere (surface to 8-20 km) Upper boundary varies from about 8 km (poles in winter) to about 20 km (tropics) Weather and climate layer Most of atmosphere’s mass; all of its water

  4. Vertical Structure of Atmosphere • Troposphere (surface to about 8-20 km) Upper boundary varies from about 8 km (poles in winter) to about 20 km (tropics) Weather and climate layer Most of atmosphere’s mass; all of its water • Stratosphere (8-20 km up to about 50 km) Ozone (O3) Layer Temperature inversion

  5. Vertical Structure (ctd.) • Mesosphere (50-80 km) • Temperature decreases with height. Why? • Thermosphere (80-? km) • Temperature inversion. Why?

  6. Vertical Structure (ctd.) • Homospherevs. Heterosphere

  7. Vertical Structure (ctd.) • Homospherevs. Heterosphere • Transition zones between layers • Tropopause • Stratopause • Mesopause

  8. Defining Layers by Function – the Ozonosphere • Roughly corresponds to the stratosphere • How does the ozone layer work? • Why is there a “hole” in the ozone layer? • Why no “hole” where the pollution is produced?

  9. Defining Layers by Function – the Ionosphere • Upper mesosphere + thermosphere • Produces the aurora borealis and aurora australis • D Layer – absorbs AM radio waves; disappears at night • E Layer – weakens at night • F Layer – reflects AM radio waves

  10. Composition of the Air • Uniform gases Nitrogen (N2) 78%, (O2) 21%, Argon (Ar) 1%, trace gases (Neon, Helium, Methane (CH4), etc.) • Variable gases Water Vapor (H2Ov), O3, CO2

  11. Composition (ctd.) • Aerosols Solid: Ice/salt crystals, soil particles, volcanic dust Condensation nuclei Liquid: Water droplets (cloud, fog)

  12. Origin of the Atmosphere • Volcanoes release H2, CO2, H2Ov, N2, NH3, CH4 No O2 or O3, so no land organisms! • One-celled aquatic organisms release CO2 to atmosphere when breaking down food through fermentation • Simple aquatic plants took in CO2 and released O2 to atmosphere via photosynthesis O3 formed from the O2

  13. Origin of Atmosphere (ctd) • CO2 gets stored in shells and decaying plants • N2 builds up in atmosphere

More Related