The Atmosphere Chapter 17.1

Lesson Objectives Identify the major components of Earth’s atmosphere Explain how air pressure changes with altitude Explain how temperature changes with altitude Describe the layers of the atmosphere Explain how the processes of radiation, conduction and convection distribute energy in the atmosphere

What is Air? A mixture of gases and particles each with their own properties Nitrogen and Oxygen make up 99% of the volume of air Argon gas 0.93% CO % Also contains: H 2 O vapor, ice, dust particles, hydrogen, salt and ozone

Structure of the Atmosphere The Atmosphere is made up of 5 different layers. Each layer is different in composition and temperature It is thickest near the surface of Earth and thins out with height until it eventually merges with space.

Layers of the Atmosphere- Troposphere Closest to Earth surface Contains most of the mass of the atmosphere Weather takes place Pollution collects There is a decrease in temperature as you travel up the Troposphere Lapse Rate The upper-limit of the Troposphere is called the Tropopause

Layers of the Atmosphere- Stratosphere Located above the Tropopause Made up primarily of concentrated ozone Ozone absorbs ultraviolet radiation from the sun So…what do you think happens here in terms of temperature? The top of the Stratosphere is called the Stratopause

Layers of the Atmosphere- Mesosphere Located above the Stratopause No ozone …so what happens to the temperature? Top of the Mesosphere is called the ……

Layers of the Atmosphere- Thermosphere Contains only a minute portion of the atmosphere’s mass Air that does exist in this layer increases in temperature to more than 1000°C Ionosphere is with thermosphere Nitrogen and oxygen atoms absorb harmful solar energy…X-rays and gamma rays Causes the high temperatures Gas particles lose electrons and become ions Auroras- Northern and Southern Lights occur

Layers of the Atmosphere- Exosphere Outermost layer of the atmosphere Lighter elements are found in this layer Above the Exosphere is outer space

Solar Fundamentals The sun is the source of all of the energy in the atmosphere This energy is transferred to the Earth and throughout the atmosphere by convection, conduction and radiation