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Weather PowerPoint Presentation

Weather

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Weather

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  1. Weather • Wind power • Wind farms 19.1

  2. Weather • Weather is the condition of Earth’s atmosphere at any given time and place • Meteorology 19.2

  3. Weather • Temperature • Amount of thermal energy in the air • Thermometers • Thermographs 19.2

  4. Weather • Temperature • Fahrenheit scale • Water freezes at 32° • Water boils at 212° 19.2

  5. Weather • Temperature • Celsius scale • Water freezes at 0° • Water boils at 100° • A Fahrenheit degree is “larger” 19.2

  6. Weather • Pressure • Force exerted by air on a standard area • Changes with temperature, elevation 19.2

  7. Weather • Pressure • Units of force per area • Lb/in² or psi • N/m² or Pa • Bar, mbar • Barometer 19.2

  8. Weather • Wind is moving air • Wind direction is the direction from which the wind is coming • Weather vane 19.2

  9. Weather • Wind is moving air • Wind speed • Anemometer • Wind is associated with changing weather • Windchill effect 19.2

  10. Weather • Precipitation is any form of water that falls to the earth’s surface from the sky • Rain is most common • Rain gauge 19.2

  11. Weather • Humidity is a measure of the amount of invisible water vapor in the air • Absolute humidity • Relative humidity • Hygrometers 19.2

  12. Winds • Pressure effects • Pressure gradient • From higher to lower pressure 19.3

  13. Winds • Coriolis effect • Deflects winds • Deflection depends on hemisphere and speed 19.3

  14. Winds • Friction effects • Friction force • Drag • Opposite of the direction wind blows • Related to wind speed 19.3

  15. Winds • Cyclones and anticyclones • Surface winds • Pressure gradient, Coriolis effect, and friction all affect the wind direction and speed 19.3

  16. Winds • Cyclones and anticyclones • Cyclonic wind pattern • Anticyclonic wind pattern • Many other factors also affect surface winds 19.3

  17. Winds • Global winds • Trade winds • Near 30° latitudes • Prevailing westerlies • Polar easterlies • Cold, dry 19.4

  18. Winds • Permanent highs, lows • Doldrums • Horse latitudes • Subpolar lows • Polar highs 19.4

  19. Winds • Local winds • Causes • Sea and land breezes • Valley and mountain breezes • Chinooks and foehns 19.5

  20. Clouds • Humidity • Warmer air can hold more water vapor than cooler air • Dew point • Condensation 19.6

  21. Clouds • A cloud is a mass of extremely tiny liquid water droplets or ice crystals in the air • Two methods of formation 19.6

  22. Clouds • Air must absorb enough water vapor to condense water droplets (or ice crystals) at its existing temperature 19.6

  23. Clouds • Air must cool to the dew point for the amount of water vapor it is holding to condense or form ice crystals 19.6

  24. Clouds • Air can cool simply by rising • Condensation nuclei • Freezing nuclei 19.6

  25. Clouds • Supercooled clouds • Liquid water at temperatures below the freezing point of water • Atmosphere must be quiet 19.6

  26. Clouds • Types of clouds • Shapes • Stratus • Cumulus • Cirrus 19.7

  27. Clouds • Types of clouds • Altitude zones • Strato- • Alto- • Cirro- • Cumulo- 19.7

  28. Clouds • Types of clouds • Fog is a stratus-like cloud that forms at ground level • Nimbus 19.7

  29. Clouds • Precipitation • Cloud water droplets are very small (about 0.02 mm) • Coalescence • Rain • Drizzle 19.8

  30. Clouds • Precipitation • Freezing rain • Sleet • Updrafts • Hail • Snow • Wintry mix 19.8

  31. Clouds • Dew forms on objects that are cooler than the surrounding air • Heavier dew forms when air is calm 19.9

  32. Clouds • Colder air cannot hold as much moisture as warmer air • Frost 19.9