1. Earth Science- Schwartz
Chapter 17
Earth Science- Schwartz

2. Weather vs. climate
Meteorology is the study of the atmosphere and the processes that cause what we refer to as “weather.”
Climatology is the long-term study of the atmosphere and the processes that cause what we refer to as “climate.”
Weather refers to the short-term phenomena.
Climate refers to the long-term patterns.

3. The atmosphere
The atmosphere is a mixture of gas molecules, small suspended particles of solid and liquid, and falling precipitation.

4. What is the atmosphere made up of?
Nitrogen 78%
Oxygen 21%
Argon less than 1%
CO2 less than 1%

5. What is the atmosphere made up of?
Some of the atmosphere’s “ingredients” change based on location, time of year and pollutants.
Water vapor is the source of all clouds and precipitation
carbon dioxide, water vapor absorbs heat given off by Earth. It also absorbs some solar energy.
Ozone is a form of oxygen that combines three oxygen atoms into each molecule (O3).
ozone filters UV radiation in the stratosphere allowing life to exist as we know it,
In troposphere ozone causes smog

6. ozone Ozone in the lower atmosphere (troposphere) = bad
ozone filters UV radiation in the stratosphere allowing life to exist as we know it,
Ozone in the lower atmosphere (troposphere) = bad
Damages our lungs, damage to plants
Ozone in the stratosphere = good
Protects us!
Warms us up

7. Other variable components of the atmosphere
Human activity adds “stuff” into the atmosphere
Primary pollutants = emitted directly from identifiable source
Secondary pollutants = not emitted directly into air.- but are created as a result of a chemical reaction that has taken place in the atmosphere

9. Height and Structure of the Atmosphere
There are 4 distinct layers of the atmosphere emerge from identifiable temperature characteristics with height.
Pressure also changes with height

10. Pressure changes with height
Atmospheric pressure is simply the weight of the air above.
Air pressure decreases with altitude, because there is less Atmosphere pushing down the higher you go!

11. Temperature changes with height
Troposphere
bottom layer of the atmosphere
temperature decreases with an increase in altitude.
stratosphere
2nd layer
temperature gradual increase because of ozone

12. Temperature changes with height
mesosphere
3rd layer
characterized by decreasing temperatures with height,
contains no O3
thermosphere
4th layer
characterized by increasing temperatures

14. Earth-Sun Relationship
Earth has 2 main motions
Rotation: spinning on axis (23.5o tilt)
Revolution: movement of Earth in its orbit around the sun
Seasonal changes occur b/c Earth’s position to the sun constantly changes as it travels along its orbit
If the axis was NOT tilted we would not have seasonal changes
Axis points to the North Star

16. The Causes of Earth’s Seasons
Summer and Winter Solstices

17. The Causes of Earth’s Seasons
Summer and Winter Solstices

18. The Causes of Earth’s Seasons
Equinox: March 21 and September 21

19. Solstice
Summer Solstice: 1st day of summer (NH leaning toward the sun) June 21 or 22
Winter Solstice: 1st day of winter (NH leaning away from the sun) December 21 or 22

20. Equinox
Autumnal Equinox: Sept. 22 or 23 in NH (occurs halfway btw the solstice)
Spring Equinox: March 21 or 22 in NH (axis neither leaning toward or away from the sun)

21. Length of day Length of daylight = Earth’s position in orbit
Summer = longer daylight
Animation