1. And Weather Atmosphere Intro Flying Paragliding
Earth’s Atmosphere
And Weather
Atmosphere Intro
Flying
Paragliding

2. Composition of the Atmosphere
78% nitrogen: little effect on weather
21% oxygen: component necessary for human life
Argon: 3rd most abundant gas; no effect on weather
Carbon dioxide: very tiny amount; absorbs energy so it is significant in heating the atmosphere
Water vapor: amount varies from 0 – 4%; it is the source of all clouds and precipitation; absorbs heat
Ozone: O3 ; located in the ozone layer in the stratosphere; blocks UV radiation
dust

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

6. Layers of the Atmosphere

7. 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 Global Solar Index Guide
Mesosphere: meteoroids, as altitude increases temperature decreases
Thermosphere: satellites orbit here; aurora borealis; as altitude increases temperature increases

8. Earth's Magnetic Field

9. Plane ride through the atmosphere

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

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

12. Earth is tilted on its axis.

13. Temperature and heat
Temperature is a measure of the average kinetic energy of the particles of an object
Heat transfer is the movement of thermal energy from a warmer object to a cooler one
Three methods of heat transfer: conduction, convection, radiation

14. Conduction
Heat is transferred through conduction when particles collide and pass movement onto or increase movement in other particles.

15. Convection
Heat transfer through the movement of a fluid (something that flows – gases as well as liquids)

16. Radiation
Transfer of heat through electromagnetic waves (infrared are specifically felt as heat)

17. Density
The concept of density is very important when considering heat.
As objects are heated they become less dense – there are less particles in a given space because the heated material expands

18. Specific Heat
The amount of heat needed to raise the temperature of one gram of material by one degree Celsius
For this class it is more important to understand that some materials (land – think about how hot sand gets in the sun) heat up and cool off faster than others and this impacts temperature and weather

19. Factors that affect temperature
Land and water: land heats and cools quicker than water; so proximity to water moderates temperature

20. Factors that affect temperature
Latitude – distance from the equator

21. Windward (upwind) locations less range in temp
Windward (upwind) locations less range in temp.; leeward (downwind) locations more range in temp.

22. Altitude: higher – cooler; lower – warmer

23. Geographic position affects temperature

24. 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.

25. 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.

26. Air pressure H L 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 H L
wind

27. Centers of low pressure or cyclones
Pressure Centers
Centers of low pressure or cyclones
Pressure decreases from outer isobars inward
Winds blow inward and counterclockwise
Bring rainy weather

28. Pressure Centers Centers of high pressure or anticyclones
Pressure increase from outer isobars inward
Winds blow outward and clockwise
Bring sunny weather

29. 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) L H
wind

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

31. Sea Breeze H L
breeze

32. Land Breeze L H
breeze

33. Atmospheric water – changes in state
sublimation
melting
vaporization
solid
liquid
gas
freezing
condensation
deposition

34. Humidity – amount of water vapor in air
Saturation – holding as much moisture as it can
Relative humidity – ratio of actual water vapor content to amount of water vapor air could hold at that temperature and pressure
sling psychrometer
Dew point - temperature to which air must cool to reach saturation

35. 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 – surface for water vapor to condense on

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

37. Orographic Lifting

38. Frontal Wedging

39. Convergence

40. Localized Convective Lifting

41. A large body of air with similar temperature and moisture
Air Masses
A large body of air with similar temperature and moisture
m – maritime : indicates
a moist airmass that forms
over water
c – continental: indicates
a dry air mass that forms
over land
P - polar: indicate a cold
air mass
T – tropical: indicates a
warm air mass
A – arctic: bitter cold air
mass

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

43. 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

44. Warm Front when a 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

45. 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

46. Stationary 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

48. Mid-latitude cyclones