1. Layers of the Atmosphere
Science 1206

2. Objectives
identify and describe the principal characteristics of layers found in the atmosphere
identify the distribution of common gases (oxygen, nitrogen, water vapour, and carbon dioxide)
investigate the relationship between altitude, temperature and atmospheric pressure

3. The Atmosphere
the atmosphere is about 500 km thick and is divided into regions
The atmospheric layers tend to be thicker over the equator than they are above the poles. This is due in part to the temperature differences, and also the gravitational pull of the Sun and Moon.

4. Troposphere:
The lowest layer of the atmosphere (layer closest to the Earth's surface) is known as the troposphere, or weather layer.
Near the poles of the Earth, the troposphere extends from the Earth's surface to an altitude about km. Near the equator the troposphere extends from the Earth's surface to an altitude about km.

5. Tropopause: Above the troposphere is the tropopause.
Because the tropopause contains slightly higher amounts of ozone which traps ultraviolet radiation, the temperature of the tropopause tends to remain relatively constant with an increase in altitude.

6. Stratosphere:
The stratosphere lies above the tropopause, but is much thicker. It contains the vast majority of ozone (the ozone layer) of any of the atmospheric layers.

7. Interesting facts: AIRPLANES NOT ALLOWED Very few airplanes can fly as high as the stratosphere because the air is so thin that there is not enough lift to keep the aircraft supported. Some spy planes do fly in the lower stratosphere, however, such as the U-2 and the SR-71.

8. Mesosphere: Thermosphere
Above the stratosphere lies the mesosphere or middle layer.
Thermosphere
The thermosphere absorbs x-rays and other radiation from the sun.

9. Exosphere:
The exosphere (atmosphere beyond 500 km above the Earth's surface) is the outermost layer of the atmosphere

10. Distribution of Common Gases (Oxygen, Nitrogen, Water Vapour, and Carbon Dioxide):
Oxygen, nitrogen, carbon dioxide and water vapour are the gases essential to life on Earth. In the lowest part of our atmosphere:
myriad of other very influential components are also present which include the water (H2O, 0 - 7%), "greenhouse" gases or Ozone (O<SUB3< SUB>, %), Carbon Dioxide (CO2, %),

12. Relationship Between Altitude, Temperature and Atmospheric Pressure:
Near the surface the average world-wide temperature is about 15 °C. At an altitude of 11 km the average temperature is °C. For every 1000m climb in altitude, the temperature will drop about 6.5 °C. -