The Earth’s ATMOSPHERE

1. The Earth’s ATMOSPHERE

2. Earth’sAtmosphere

3. Weather

4. Weather AFFECTS Lives of individuals World economy Agriculture Energy use Water resources Transportation Industry Weather influence our lives a great deal People influence the atmosphere and its behavior as well

5. Weather VS Climate Weather • Constantly changing • Refers to the state of the atmosphere at a given time and place. • Changes are continuous and seemingly erratic

6. Weather VS Climate Climate • Description of aggregate weather conditions • Based on observations that have been accumulated over many years • Average weather, character of the area, variations and extremes • Sum of all statistical weather information that helps describe a place or region

7. Weather forecasts that go beyond a few days are not reliable • Climate is the atmospheric conditions that are typical for that place

8. Climate data CANNOT predict weather

9. “Climate is what you expect, but weather is what you get”

10. METEOROLOGY • The study of the physics, chemistry, and dynamics of the Earth’s atmosphere

11. CLIMATOLOGY • Study of climate types and patterns and the causes of those patterns

12. Basic Elements of Weather and Climate • Air temperature • Humidity • Type and amount of cloudiness • Type and amount of precipitation • Air pressure • Speed and direction of the wind

13. Weather VS Climate Weather Climate Slowly – varying Averages (monthly, yearly) Ranges (largest value – smallest value) Extremes (maximum, minimum) • Conditions at a given time and place • Constantly changing

14. Weather or Climate??? • The average high temperature for the month of July in Phoenix is 111oF. • Cumulus clouds presently cover the entire sky. • Snow is falling at a rate of 1 inch per hour. • The summers here are warm and humid. • At 3:00 PM, winds were blowing from the NW at 10 mph. • Total precipitation at O’Hare Airport for 2003 was 32.02 inches, which is 4.25 inches below normal.

15. Composition of the Atmosphere • Air • Not a unique element or compound • Mixture of many discrete gases in which varying quantities of tiny solid and liquid particles are suspended.

16. Composition of Air • Not constant • Varies from time to time • Varies from place to place • If water vapor, dust, and other variable components are removed, the makeup is very stable worldwide up to an altitude of about 80km (50mi)

17. Clean Dry Air • Nitrogen and Oxygen makes up 99% • Have great significance to life on earth • Minor importance in affecting weather phenomena Carbon dioxide, 0.037% Important constitute of air Efficient absorber of energy emitted by the earth Influences the heating of the atmosphere

18. Variable Components of Air • Water vapor • Dust particles • Ozone

19. Water Vapor • From 0 to 4% by volume • Source of all clouds and precipitation • Absorb heat given off by earth as well as some solar energy • Latent heat – hidden heat • As water changes from one state to another, heat is absorbed or released • Energy source that helps drive many storms

20. Aerosols • Tiny solid and liquid particles • Natural or human made • Sea salts from breaking waves • Fine soil blown into the air • Smoke and soot from fires • Pollen and microorganisms lifted by the wind • Ash and dust from volcanic eruptions and others

21. Aerosols Significance • Many act as surfaces on which water vapor can condense, important function in the formation of clouds and fogs • Absorb, reflect, and scatter incoming solar radiation • Contribute to an optical phenomenon we have all observed, the varied hues of red and orange at sunrise and sunset

23. Ozone • Form of oxygen that combines three oxygen atoms into each molecule (O3) • Very little in the atmosphere and its distribution is not uniform. • In the lowest portion of the atmosphere, it represents less than one part in 100 million. • Concentrated above the surface in the stratosphere between 10km to 50km

24. Ozone • In the altitude range, oxygen molecules (O2) are split into single atoms of oxygen (O) when they absorb ultraviolet radiation emitted by the sun. • Must happen in the presence of a third, neutral molecule that acts as a catalyst by allowing the reaction to take place without itself being consumed in the process.

25. Ozone’s Presence • Crucial to those who live on earth • Absorbs the potentially harmful ultraviolet radiation from the sun • If ozone did not filter a great deal of the ultraviolet radiation, and if the sun’s UV rays reached the surface of the earth undiminished, our planet would be uninhabitable for most life as we know it

26. Anything that reduces the amount of ozone in the atmosphere could affect the well-being of life on earth.

27. Ozone DepletionA Global Issue

28. Ozone Depletion • CFC Chlorofluorocarbons • Coolants for air-conditioning and refrigeration equipment, cleaning solvents for electronic components, propellants for aerosol sprays, and the production of certain plastic foams

29. Threats of UV radiation • Increased risk of skin cancer • Impair human immune system • Promote cataracts, clouding of the eye lens that reduces vision and may cause blindness if not treated

30. Montreal Protocol • Developed under the sponsorship of the United Nations • Eliminate the production and use of CFCs • More than 180 nations eventually ratified the treaty

31. According to US Environmental Agency, the ozone layer has not grown thinner since 1998 over most of the world • Between 2060 and 2075, the abundance of ozone-depleting gases is projected to fall to values that existed before the ozone hole began to form in the 1980s

32. Announcements Quiz December 18, 2013