1. The Atmosphere A thin fragile shell of gases that provides all our weather and allows life on earth

2. troposphere stratosphere mesosphere thermosphere

3. Air is mostly nitrogen (78%) and oxygen (21%) In humid air, water vapor becomes a significant gas

4. Atmosphere Basics  The lower atmosphere is a fairly homogeneous mixture of gases.  Water vapor occupies up to 4% of the volume of the atmosphere  The density of air is influenced by temperature and water content

6. The red line is air pressure Why is this so? What happens to pressure with increasing altitude?

7. Atmospheric Pressure Pressure is measured by barometers Warm air is less dense, therefore has lower pressure Cold air is more dense, therefore has higher pressure Humid air (lots of water vapor) has lower pressure, since H 2 0 (18) weighs less than N 2 (28)

8. Air pressure can be measured with a simple mercury barometer Remember though that air pressure is exerted in all directions and not just down This type of barometer measures pressure in inches or centimeters of mercury

9. Or with a spring type barometer called an Aneroid barometer This type of barometer uses units of pressure called millibars or it can also show inches of mercury Average sea level pressure = 29.92” of mercury = 1013.2 millibars This is also known as 1 atmosphere

11. How the Atmosphere is Heated The SUN is the source of most heat In general, the more INSOLATION, the warmer the atmosphere (and the Earth’s surface) will be

12. How the Atmosphere is Heated 1)Conduction: hot Earth warms air above it 2)Direct absorption of Sun’s heat by gases in atmosphere 3)Absorption of infrared heat radiated from Earth’s surface 4)Condensation of water releases stored heat 5)Coriolis affect: friction between atmosphere and Earth due to rotation

13. From Reference Tables

14. What is the reason for the temperature drop in the troposphere? What is the reason for the temperature rise In the stratosphere? What is the reason for the temperature soaring In the thermosphere?

15. How Heat is Transferred in the Atmosphere 1)Convection currents: density differences moves air in circles (wind) 2)Rising air (less dense) cools as it expands RECC (Rising air Expands Cools Condenses) 3) Sinking air (more dense) heats up as it is compressed SCWE (Sinking air Compresses Warms Evaporates)

16. ? Why will these balloons Rise into the atmosphere? Yes because the air in them Becomes hotter and less dense than the surrounding air

17. Usually the temperature gets colder with increasing height in the troposphere As long as the air in the balloons stays warmer than the surrounding air it will continue to rise up

18.  Uneven solar heating  The Coriolis effect Moving Air is called WIND. What causes WIND?

19. Uneven Solar Heating and Latitude

20. Moving masses of air and ocean currents transport energy from locations with a surplus to those with a deficit.

21. deflection of a moving object, caused by the moving frame of reference on the spinning Earth. How does this apply to the atmosphere? As air warms, expands, and rises at the equator, it moves toward the pole, but instead of traveling in a straight path, the air is deflected eastward. In the N. Hemisphere air turns to the right. In the S. Hemisphere air turns to the left. The Coriolis Effect

22. Heat Transport + Coriolis

23. Cell Circulation Drives Wind Patterns The doldrums are calm equatorial areas where two Hadley cells converge. The horse latitudes are areas between Hadley and Ferrel cells. There is little surface wind in this area. The trade winds are surface winds of Hadley cells. The westerlies are surface winds of Ferrel cells. Wind Patterns

24. 2-D Winds

25. Monsoons are seasonal patterns of wind circulation. Characterized by dry winters and wet summers. Sea breeze is cool air from over the water moving toward land. Sea breezes occur after sunrise. Land breezes occur after sunset when air cooled by the land blows toward the water. Differential Heating

26. Sea Breezes And Land Breezes Top: Sea breeze Bottom: Land breeze

27. Monsoon: A seasonal wind that changes direction from NE in winter to SW in summer RAINY SEASON!

28. Atmospheric Circulation High altitude air current of very strong westerly winds ( up to 250 mph) flowing above the middle latitudes.

29. Effect of Air Movement on Water Friction between moving air and water causes WAVES Ocean Currents are caused by the prevailing winds, and tend to show circular patterns due to Coriolis affect: spin clockwise in N. Hemisphere, counterclockwise in S. Hemisphere