Ch. 3 Weather and Climate

1. Ch. 3 Weather and Climate http://www.youtube.com/watch?v=lrPS2HiYVp8

2. Section 1 Factors Affecting Climate • The Sun and Latitude A. Weather is the condition of the atmosphere at a given time and place B. Climate-weather conditions in a region over a long period of time C. The closer you are to the tropics and the sun’s direct rays, the warmer you are…duh

3. Temperature-measurement of heat • Atmosphere reflects half of sun’s energy and absorbs the other half which heats up the earth • Greenhouse Effect-Earth allows sun’s heat in, traps it and slowly allows it to release into space G. Global Warming-CO2 absorbs heat H. Some say man is responsible while others say it’s a natural cycle

5. Do you know? • How does the Earth’s Atmosphere help keep the planet Warm? • Green house effect- slowing the loss of heat into space

6. Random Fact • Venus and global warming • Venus is 96 % CO2 and because of this it is 890 F • The Little Ice age 1500’s -1800’s

7. Atmospheric Pressure A. Pressure of air B. Higher you go, less pressure C. As air heats up, it expands, becomes less dense and rises (low pressure system)

8. D. Air rises, cools and forms water vapor E. Centers of low pressure systems are called cyclones… sometimes a slight breeze while other times a powerful storm F. High pressure systems are created from cold air sinking towards the Earth G. Usually bring stable, clear and dry weather

9. Do you Know • What kind of weather is usually associated with an area of Low pressure? • Unstable weather, anything from a slight breeze to bad storms

10. H. Look at pressure diagram on Page 43. III. Global Wind Belts A. Wind flows from high pressure areas to low pressure areas B. Tire C. Prevailing winds-blow from the same direction all the time…NE and SE trade winds, westerlies, easterlies D. Doldrums-along Equator, calm…little wind

12. E. Front-two air masses of widely different temperatures or moisture levels meet F. Usually results in precipitation G. Prevailing winds up in atmosphere make up the jet stream… wind speed can reach 300 miles per hour H. Jet streams move heat and major weather patterns

14. Do you Know? • How is wind directly related to the differences of air pressure? • Wind flows from high areas of high pressure to low pressure areas

15. Ocean and Currents A. Water heats and cools more slowly than land B. Locations near large bodies of water have more consistent temps then inland locations C. Earth’s wind, rotation and temperatures create currents (great rivers of sea water) D. Move clockwise in NH and counter in SH

17. Currents help balance water temperatures in the oceans by moving it all around.

18. Do you know? • What are the main forces that create ocean currents? • Wind, earth’s rotation, varying ocean temperatures

19. Section 2: Weather Factors Read to Discover • What are the common forms of precipitation, and how are they formed? • How do mountains and elevation affect weather and climate? • What are the different types of storms, and how do they form?

20. Formation of Precipitation Condensationclouds, dew, fog, frost Evaporation Humidity Rain Snow Sleet Hail Section 2: Weather Factors

21. Section 2: Weather Factors • Rain—Liquid formed through condensation of water vapor • Snow—Ice crystals formed in clouds • Sleet—Rain that freezes as it falls • Hail—Chunks of ice formed in storm clouds Forms of Precipitation

22. Section 2: Weather Factors • Increase in elevation causes drop in temperature. • Mountains cause orographic effect: Moist air meets a barrier and is pushed upward, causing cooling, condensation, and precipitation. • Mountainside facing wind is the windward, wetter side; side facing away from wind is the leeward, drier side, called the rain shadow.

23. Section 2: Weather Factors Types of Storms • Middle-latitude storms form when cold, dry polar air mixes with moist, warm tropical air. Examples include thunderstorms and tornadoes. • Tropical storms are usually smaller and lack fronts. Examples include hurricanes and typhoons.

24. Section 3: Climate and Vegetation Patterns Read to Discover • How do the two tropical climates differ? • What conditions are common in dry climates? • What climates are found in the middle latitudes? • What characterizes high-latitude and highland climates?

25. Section 3: Climate and Vegetation Patterns Tropical Wet and Dry Climates Tropical Humid Climate • Close to equator • Warm temperatures • Rainfall all year • Receives Sun’s rays directly all year • Rising warm air • Rain forests • Monsoons • North and south of tropical humid • Caused by seasonal change in this area • Alternating wet and dry seasons • Savannas

26. Section 3: Climate and Vegetation Patterns • Generally centered about 30 degrees north and south of equator • Subtropical high-pressure zone causes sinking dry air, with little rain. • Winters may be very cold, summers very hot. • Hardy plants and animals Dry Climate Areas

27. Section 3: Climate and Vegetation Patterns • Mediterranean—Long, dry summers and mild winters; scrub woodland vegetation • Humid Subtropical—Hot, humid summers and mild winters; temperate forests • Marine West Coast—Mild all year; may support dense forests • Humid Continental—Variable, with four seasons; enough rain to support forests Middle-Latitude Climates

28. Section 3: Climate and Vegetation Patterns • Subarctic—Long, cold winters and short, warm summers; vast evergreen forests • Tundra—Long winters, with permafrost; low shrubs, lichens, mosses, ferns • Ice Cap—Polar climates; few land plants or animals • Highland—Varies by elevation, with low elevations relatively mild and high elevations similar to ice cap High-Latitude and Highland Climates