1. Earth’s Atmosphere And Weather

2. Composition of the Atmosphere 78% Nitrogen 21% Oxygen 0.9% Argon 0.04% Carbon Dioxide Water Vapor 0 – 4% 0.000004% Ozone Other Trace Gasses – Neon, Helium, Methane, Hydrogen, Nitrous Oxide Dust } 99% Just for These Two

3. Comparison of Earth ’ s diameter to the thickness of the atmosphere The diameter is 12734.9km The atmosphere is approximately 100 km.

4. Layers of the Atmosphere

5. Layers of the atmosphere Troposphere: – lowest layer; as altitude increases temperature decreases; where weather is located Stratosphere: – jet stream; airplanes fly here; as altitude increases temperature increases; ozone layer Mesosphere: – meteoroids, as altitude increases temperature decreases Thermosphere: – satellites orbit here; aurora borealis; as altitude increases temperature increases

6. A Journey Through the Atmosphere

7. Earth’s Rotation and Revolution Earth revolves around the sun once every 365 days.

8. Earth rotates on its axis once every 24 hours.

9. Earth is tilted on its axis.

10. Temperature and Heat Heat – Energy - Average kinetic energy of the particles of an object Temperature – The Measurement of Heat Heat Transfer – the is the movement of thermal energy from a warmer object to a cooler one Three methods of heat transfer – conduction, convection, radiation

11. Factors that affect temperature Land heats and cools quicker than water; water moderates temperature

12. Windward locations have less range in temp.; Leeward locations have more range in temp.

13. Altitude Higher = cooler Lower = warmer

14. Geographic position affects temperature

15. Cloud cover and albedo Albedo is the fraction of total radiation that is reflected by any surface. Many clouds have a high albedo so they reflect much of the sunlight that strikes them back into space.

16. Affects of cloud cover In the day, clouds reduce incoming solar radiation and have a cooling effect. At night, clouds absorb radiation from the land and reradiate it back to Earth increasing nighttime temperatures.

17. Air pressure air pressure -is the pressure exerted by the weight of air above measured with a barometer Horizontal differences cause wind Isobars connect places (on a weather map) of equal pressure. Spacing of isobars indicates amount of pressure change. Exerted in all directions HL wind

18. Centers of Low Pressure (cyclones) 1.Pressure decreases from outer isobars inward 2.Winds blow inward and counterclockwise 3.Bring rainy weather Pressure Centers

19. Centers of High Pressure (anticyclones) 1.Pressure increase from outer isobars inward 2.Winds blow outward and clockwise 3.Bring sunny weather

20. Wind Wind is caused by differences in air pressure. Unequal heating of earth’s surface causes air pressure differences – the heating is from solar radiation Pressure differences – greater difference in pressure greater the wind speed The Corealis Effect deflects the wind to the right Friction between the air and the earth’s surface slows wind and changes its direction Above the friction layer - the jet stream (120 – 240 km/hr) H L wind

21. Wind Speed is measured using a anemometer. Wind speed is named from the direction the wind comes from. Wind direction is indicated by a wind vane.

22. Sea Breeze LH breeze

23. Land Breeze L H breeze

24. Atmospheric water – changes in state solidliquidgas meltingvaporization freezingcondensation sublimation deposition

25. Humidity – amount of water vapor in air Saturation Relative humidity – Ratio of actual water vapor content to amount of water vapor air could hold at that temperature and pressure Dew point – Temperature to which air must cool to reach saturation

26. Cloud Formation Adiabatic Temperature Changes – no addition or subtraction of heat – Occur when air expands (it cools) and when it compresses (it warms) – As a parcel of air rises high enough it will cool to dew point and condensation will begin – Condensation nuclei

27. Processes that lift air Orographic Frontal wedging Convergence Localized convective

28. Orographic Lifting

29. Frontal Wedging

30. Convergence

31. Localized Convective Lifting

32. Air Masses A large body of air with similar temperature and moisture

33. Fronts Boundaries separating air masses – Include cold fronts, warm fronts, occluded fronts and stationary fronts

34. Cold Front Boundary where a cold air mass is entering an area of warm air Symbol blue line with triangles pointing toward the warm air Brings strong heavy rain and possible violent storms Temperature – warmer ahead of front, cooler after front passes Clouds: ahead of front- cirrus, stratocirrus, and cumulonimbus; at front – cumulonimbus; behind front - cumulus

35. Warm Front Warm air mass overrides a cold air mass Symbol – solid red line With semicircles pointing toward the cold air Brings light to moderate rain, sleet or snow

36. Occluded front When a cold front catches up with a warm front Symbol – a solid line with alternating triangles and semicircles pointing in the direction the front is moving Brings light, moderate or heavy continuous rain

37. Stationary Front Occurs when a warm front Or cold front stops moving Symbol – solid line with alternating triangles and semicircles; triangles point toward the warm air and the semicircles point toward the cold air Brings long periods of precipitation

38. Cold Fronts and Warm Fronts

39. Mid-latitude cyclones

40. Life of a Mid-Latitude Cyclone