1. Unit 2: atmosphere

2. Earth’s atmosphere and oceans shapes our climate and weather
Introduction
Earth’s atmosphere and oceans shapes our climate and weather
The atmosphere is complex, and in a state of dynamic balance
Today, humans are altering this balance

3. The structure of the atmosphere
Nitrogen, oxygen, argon, & water vapor make up most of the atmosphere
Trace amounts of other gases
Composition and ratio of gases remain relatively constant

4. The structure of the Atmosphere
Earth’s atmosphere extends 560 km above the surface
4 layers, each with different properties

5. The structure of the atmosphere
Troposphere- lowest layer (8-16 km up)
Most weather occurs here
Warmed up from below when solar radiation heats the surface of Earth
Temp decreases 6.5 degrees C per kilometer of altitude

6. The structure of the atmosphere
Tropopause- layer of cold air (-60 C), causes water vapor to condense
Stratosphere- from tropopause to 50 km up

7. The structure of the atmosphere
Stratosphere- temps increase with altitude
90% of the ozone is here
Not much water vapor due to tropopause
Stratopause- temps peack at (-3 C)

8. The structure of the Atmosphere
Mesosphere- temps fall as you go up
Lowest temp is -93 C at 85 km up
Thermosphere- temps increase higher than 1700 C

9. The structure of the atmosphere
Atmospheric pressure is greatest at sea level (14.7 lbs/in^2)
Pressure decrease as you increase your altitude (less air pressing down on you)

10. Earth’s temp has remained fairly constant over time
Greenhouse effect
Earth’s temp has remained fairly constant over time
Earth radiates energy back to space balancing energy that we receive from the sun

11. The albedo of Earth reflects some of the solar radiation back to space
Greenhouse effect
Solar radiation may be absorbed by clouds, the atmosphere, or the surface of Earth.
The albedo of Earth reflects some of the solar radiation back to space

12. Some reflected energy from Earth is trapped in the atmosphere
Greenhouse effect
Some reflected energy from Earth is trapped in the atmosphere
Greenhouse Effect
Clouds, water vapor, and greenhouse gases can absorb this solar radiation

13. Greenhouse effect
The greenhouse gases (carbon dioxide, methane, and nitrous oxide) radiate the energy back to Earth and warms the planet even more

14. You have a container holding 150 parts of atmospheric gas.
MATH
You have a container holding 150 parts of atmospheric gas.
Calculate the following amounts of gases in the container

15. Nitrogen Helium Oxygen Methane Argon Nitrous Oxide Carbon Dioxide
math
Nitrogen Helium
Oxygen Methane
Argon Nitrous Oxide
Carbon Dioxide
Ozone

18. Major Greenhouse gases
Greenhouse Gas= GHG
Most occur naturally in the atmosphere
Some are synthetic

19. Natural sources= volcanoes, breathing, fires
Major GHGs
Carbon Dioxide= CO2
GHG affected directly by humans
Combustion of fuels or decay of biomass
Natural sources= volcanoes, breathing, fires

20. Main sources of CO2 increase
Major GHGs
Main sources of CO2 increase
Burning fossil fuels
Deforestation
less plant life or different plant life means the ecosystem cannot store as much carbon

21. Methane= CH4 Anaerobic decay (without oxygen)
Major GHGs
Methane= CH4
Anaerobic decay (without oxygen)
Fermentation (farts) in ruminant animals like cattle
Manure/wastewater treatment
Fossil fuel combustion

22. Nitrous Oxide= N2O Fertilizer use Animal waste management
Major GHGs
Nitrous Oxide= N2O
Fertilizer use
Animal waste management
Fossil fuel combustion
Industrial activities

23. Hydrofluorocarbons (HFCs) & Perfluorocarbons (PFCs)
Major GHGs
Hydrofluorocarbons (HFCs) & Perfluorocarbons (PFCs)
Synthetic chemicals
By-product of aluminum smelting
Refrigeration, air conditioners
Foam-blowing insulation

24. It takes many years to notice the temp. change
Major GHGs
The increase in GHGs increases the ability of Earth’s atmosphere to trap radiant energy
It takes many years to notice the temp. change
Oceans can store lots of heat

26. Vertical motion in the atmosphere
Many weather patterns start with rising air
Increasing the temp of air with constant pressure causes it to expand.
Warmer air is less dense
Less dense air is more buoyant than denser air

27. Vertical motion in the atmosphere
Water is a key factor in weather/climate
1-2% of atmosphere is water vapor

28. Vertical motion in the atmosphere
Relative humidity= compares amount of water vapor present to the max amount air can hold
100% relative humidity=air cannot hold any more water vapor
(muggy air)

29. Vertical motion in the atmosphere
As air warms, the amount of water vapor air can hold increases.
Water vapor concentrations are highest in warm regions, and lowest near the poles

31. Vertical motion in the atmosphere
Adding moisture to air makes it less dense (wet air will rise)
Latent energy= moist air has the potential to warm the surrounding air when the water condenses

32. Vertical motion in the atmosphere
Dew point= temperature at which air would have to cool to be fully saturated (can’t hold any more water)
When air cools to its dew point, clouds form and precipitation can start

33. Vertical motion in the atmosphere
Unstable atmosphere is more likely to produce clouds and storms
Air masses rise and form clouds if they have enough water vapor to warm them as they expand

34. Vertical motion in the atmosphere
Air masses rise by:
Winds pushing them up mountain ranges, cooling the air and forming clouds
Convergence= air masses collide, pushing one up (thunderstorms)

35. Vertical motion in the atmosphere
Convergence continued:
Cold & warm front collide
Cold=denser, so it sinks
Warm air rises, cools, and clouds form
If it is lifted fast/strong enough, you get intense storms

36. Atmospheric circulation patterns
Atmospheric circulation= movement of air masses
Vertical=Warm air rising=vertical
horizontal-=Wind created by air moving from high to low pressure

37. Atmospheric circulation patterns
Isobars= parallel lines on a weather map indicating areas of air with the same pressure

39. Atmospheric Circulation patterns
Sea breezes (Day)
The land heats up faster on land, air rises
Warm air moves over water and cools
Air of water is cooler, moves in to land

40. Atmospheric Circulation patterns
Sea Breeze (Night)
Land cools quicker than water, cool air moves out to water
Air over water warms, rises
Warm air moves back over land and cools

42. Atmospheric Circulation patterns
Wind over very long distances appear to curve
Coriolis Fore=caused by Earth’s rotation
Equator spins faster than near the poles

43. Atmospheric Circulation patterns
Earth spinning causes objects on Earth to have angular momentum
Objects spin faster the closer they are to the reference point
Figure skater pulling in their arms

44. Atmospheric Circulation patterns
Same effect on air mass going from equator to pole
The closer to Earth’s reference point (the poles) the faster the air mass spins
Northern hemisphere (turn right)
Southern hemisphere (turn left)

46. Atmospheric Circulation patterns
Coriolis force causes hurricanes in the Northern Hemisphere to spin counterclockwise and clockwise in the Southern Hemisphere

47. Atmospheric Circulation patterns
Air circulates clockwise in a high pressure system
Air circulates counterclockwise in a low pressure system

49. Atmospheric Circulation patterns
Air move towards and up in low pressure systems
Air move down and out of high pressure systems

51. Atmospheric circulation patterns
Hadley Circulation (starting at the equator)
Warm, moist air rises
The warm air moves to cooler regions north or south of the equator

52. Atmospheric circulation patterns
As the air mass moves, it looses its moisture through precipitation
Cool, dry air descends
The air then warms and collects moisture up and along the surface
Repeat

54. Climate, Weather, and Storms
Weather=atmospheric conditions at a certain place and time
Climate= long-term weather trends in a specific region
Climate is what you expect, weather is what you get

55. Climate, Weather, and Storms
Circulation patterns create predictable climate zones
50-60 degrees north & south latitudes have lots of precipitation
30 degrees north and south latitudes are dry from descending air

57. Climate, Weather, and Storms
Air pressures increase sharply between middle latitudes (40 degrees) and the poles
This causes the jet stream

58. Climate, Weather, and Storms
Jet stream flows west to east
Transport heat as they shift north and south
Jet stream bring much of the weather to our area
In the winter, a dip in the jet stream from Canada brings arctic air to us

59. Climate, Weather, and Storms
Hurricanes
Form over tropical waters (8-20 degrees latitude)
Most active area is western Pacific

60. Climate, Weather, and Storms
Signs of a potential hurricane
Appearance of a tropical disturbance
Feedback loop: falling pressure pulls more air in, making more warm air rise, releasing more pressure.
Counterclockwise circulation

61. Climate, Weather, and Storms
Pressure near the top of the storm rises
Air flows outward at the top, cools, and then drops down forming powerful winds
This circulation keeps the storm strong

63. Climate, Weather, and Storms
If hurricanes move over cooler water or land, they will diminish in size and strength

64. Global carbon cycle
GHG emissions are affecting the natural carbon cycling between land, atmosphere, and oceans
The rate land and ocean takes in carbon determines how much is left over in the atmosphere

65. Humans are interfering with the natural balance of the carbon cycle
Global carbon cycle
Humans are interfering with the natural balance of the carbon cycle
Atmospheric CO2 is rising rapidly and higher than it has been in 650,000 years.

66. The oceans and land stored the rest
Global carbon cycle
In recent decades, only half the CO2 added by humans stayed in the atmosphere
The oceans and land stored the rest

67. On average, carbon spends this much time in :
Global carbon cycle
On average, carbon spends this much time in :
Atmosphere=5 years
Land plants=10 years
Oceans=380 years
Ocean sediments/fossil fuels=millions of years

68. Global carbon cycle
Oceans can take in CO2, almost all in the atmosphere, but it would take 500 years
Only a small portion of the ocean contacts the atmosphere

69. Photosynthesis from marine and land plants can take up CO2
Global carbon cycle
Photosynthesis from marine and land plants can take up CO2
Most returns to the atmosphere later, but some is stored for a long time