1. Meteorology
Unit 6

2. Energy Exchange in the Atmosphere
________- the state of the atmosphere at a given time and place. ____________- the study of the entire atmosphere including its weather. Atmospheric variables- temperature, wind, humidity, pressure, and atmospheric transparency
Weather
Meteorology

3. A. Energy Transfer in the Atmosphere
_____________-the transfer of energy by movements of liquids and gases (fluids)
-movements are caused by differences in densities in the fluids.
-heat is carried by ____________________
(______________)
Convection
convection currents
convection cell
Water becomes colder, more dense, and sinks
Water becomes warmer, less dense, and rises

4. 2. _______________- transferring heat by touching an object i. e
2. _______________- transferring heat by touching an object i.e. pan on stove, air on radiator, air on earth’s surface 3. ________- the transfer of electromagnetic energy through space. -heat emanating from a body as wavelengths of energy
conduction
radiation

5. B. Heat Balance Energy enters and leaves Earth by radiation.
___________-incoming solar radiation
Energy that Reaches the Atmosphere
30% reflected back into space
70% absorbed
- 19% absorbed by water vapor, clouds, ozone, and dust
- 51% absorbed by earth’s surface
- 21% of energy is radiated back by surface
-30% of energy is transferred to atmosphere by conduction and convection
insolation

6. The Greenhouse Effect
Short wavelengths of energy from the sun pass through the gases of the atmosphere but the longer wavelength radiation given off by the surface is reflected back to the surface
The is increasing the greenhouse gases
burning of fossil fuels

7. Greenhouse Gases
Carbon Dioxide
Methane
Water Vapor

8. Electromagnetic Spectrum p. 14 in the Reference Tables

9. Greenhouse Effect
long wave, infrared radiation is released from surface

10. C. Factors Affecting Atmospheric Variables
Temperature-measure of the energy of molecules
a. Latitude- higher latitude -lower temperatures
b. Altitude- higher altitude -lower temperatures
c. Closeness to large bodies of water - less fluctuation in temperature of nearby land areas
*Due to specific heat capacity- water has a high specific heat, meaning it heats up and cools down more slowly than land.

11. a. temperature –the higher it is, the more moisture the air can hold
2. moisture- liquid (water droplets), solid ice and snow), gas (water vapor)
a. temperature –the higher it is, the more moisture the air can hold
b. capacity – the amount of water vapor the air can hold
c. saturated – the air contains all the water vapor it can at that temperature
d. dewpoint temperature –temperature at which condensation occurs
e. absolute humidity – the amount of water vapor actually present in the air
f. relative humidity – a comparison between the amount of moisture in the air and the amount the air can hold.
-if the air is “half full” of water, the relative humidity is 50%

12. When is Relative Humidity 100%?
When is Relative Humidity highest?
When is Relative Humidity lowest?
Notice when the high and low temperatures are for the day. Why?

13. Sling Psychrometer
-________________- instrument used to find dewpoint. -two thermometers (one “wet”, one “dry”); as water evaporates from the wet thermometer, the temperature drops. The drier the air, the more it evaporates, and the more it drops.
Psychrometer

16. 3. Pressure
Air Pressure- the force, or weight, of the air pushing down on a unit surface area
-also called ______________________or ____________________.
___________- the greater it is, the higher the pressure.
______________- the greater it is, the less the density and pressure.
atmospheric pressure
barometric pressure
density
temperature

17. ________________- instrument used to measure atmospheric pressure
Aneroid Barometer
Barometer
________________- instrument used to measure atmospheric pressure
________- lines on weather maps joining places with equal air pressure
Isobars
Mercury Barometer

18. As air temperature increases, air pressure decreases.
Inverse Relationship

19. c. moisture- the more moisture in the air, the
the atmospheric pressure.
d. altitude- as altitude increases, the density and pressure of the air
lower
decrease

20. D. Air Movement
winds
_______- large horizontal movements of air near the Earth’s surface
_________- local horizontal movements of air
_________- vertical air movements
Pressure gradient- the rate of change in pressure between two locations.
Steep pressure gradient- isobars are
and winds are
Gentle pressure gradient- isobars are and winds are
breezes
currents
close together
strong
far apart
light

21. Land and Sea Breezes -occur because land and
faster than water
-sea breeze- onshore breeze
-land breeze- offshore breeze
heats up
cools off
Land and Sea Breeze Animation
NOAA Website for Diagrams
Air always moves from high to low pressure

22. Convection Cells
-occur because gravity pulls cool, dense air toward the Earth’s surface, forcing warmer, less dense air to rise.
-zones of high pressure regions where air descends and spreads out (dry).
-zones of low pressure regions where air comes together and rises (wet) L H
divergence
convergence

23. Planetary Winds
-If the earth did not rotate, air would at the equator and at the poles, creating a large convection cell.
-Since the earth does rotate, winds are modified by the Coriolis Effect. They are deflected to the in the Northern Hemisphere and to the in the Southern Hemisphere (causes wind belts and jet streams).
rise
sink
right
left

24. Major Wind Belts North and South Poles- Polar Highs
60°N to 90°N, 60°S to 90°S- Polar Easterlies
30°N to 60°N, 30°S to 60°S- Prevailing Westerlies
30°S and 30°N- Horse Latitudes
0° to 30°N- Northeast Trades
0° to 30°S - Southeast Trades
Equator- Doldrums and Intertropical Convergence Zone (ITCZ)

25. Prevailing Westerlies
Subpolar High
Polar Easterlies
Northeast Trades
Horse Latitudes
Doldrums
Southeast Trades
Polar Easterlies
Prevailing Westerlies
Subpolar High

26. Jet Streams Bands of swiftly moving winds
Move in an west to east direction
Found near the top of the troposphere
Thousands of kilometers long
Hundreds of kilometers wide
One kilometer from top to bottom
Our weather is affected by a polar jet stream, which is stronger than the tropical jet stream

28. Reference Tables p. 14

29. E. Clouds and Precipitation
Condensation- process by which gaseous water vapor changes to
-must condense onto a
-occurs when the air is
Condensation nuclei- particles in the air such as
that water condenses on
Deposition- when water vapor changes directly into a solid (ice or snow).
-temperature must be below
______- condensation of water onto the ground
______-deposition of water onto the ground
liquid
surface
saturated
dust or salt
zero °C
dew
frost

30. Clouds- collections of tiny water droplets or ice crystals suspended in the atmopshere
-Air rises vertically, expands, and cools. If it cools to the dewpoint temperature, clouds form.
________________-occurs when mountains act as barriers to the flow of air, forcing it to rise to get to the other side
____________- occurs when warm, lighter air rises over cool air
orographic lifting
frontal wedging

31. Cloud Types _______________- low rain clouds
_______________-thunderclouds
___________- fair weather (heap) clouds
___________- fair weather (high, wispy) clouds
____- cloud resting on the Earth’s surface
nimbostratus
cumulonimbus
cumulus
cirrus
fog

33. Precipitation- the falling of liquid or solid water from clouds
_______- large falling drops of water
_______- fine falling drops of water
_______- rain that freezes as it forms
_______- falling ice crystals
_______- when water droplets freeze and start to fall they collect water and are forced upward, freeze again, fall, collect water, and are forced upward, etc.
Seeding- placing into the atmosphere where there is some available water vapor
rain
drizzle
sleet
snow
hail
condensation nuclei

34. F. Weather Maps
Station Models

35. Isobars- isolines connecting points of equal
Isotherms- isolines connecting points of equal
Pressure gradient- high (steep) where isobars are ; this produces strong winds
_______- the boundary between two different air masses
-moving in the direction of the triangles or half-circles
pressure
temperature
close together
front

36. Weather Map of the United States
Cold, Dry Air L H
Warm, Moist Air

37. Air Masses
Air mass- huge body of air in the troposphere having similar
-characteristics depend upon their geographic region of origin (source region).
__________(m)- air masses that develop over water (moist)
__________(c)- air masses that develop over land (dry)
_________(P)- air masses that develop over higher latitudes (cool)
_________(T)- air masses that develop over lower latitudes (warm)
characteristics
maritime
continental
polar
tropical

38. Air flows from west to east across the United States.
Jet Stream- narrow, fast moving current of air that flows just below the tropopause
Air flows from west to east across the United States.

39. cyclone (low)- low-pressure air-mass with the winds moving counter clockwise toward its center
-often produce rain
____________(high)- high pressure air-mass with winds moving in a clockwise direction away from its center
-cool, clear weather
anticyclone

40. Fronts -the boundary (interface) between two air masses
-usually (meaning they have big differences between temperature and moisture)
-often produce
-the half-circles and triangles point in the direction the air-masses and front are moving.
unstable
clouds, strong winds, precipitation, temperature and pressure changes

41. __________- occur when warm air meets and rises over cold air on the ground
-long gentle slopes (1000km)
-cause extended periods of precipitation
warm fronts mT cP

42. 2. __________- occur when cold air meets and pushes out warmer air
-short, steep slopes
-move faster than warm fronts
-cumulonimbus clouds- violent thunderstorms
-precipitation falls for a very short period of time
-abrupt weather change, winds shift from southerly to northerly
cold fronts

43. Cold Front
Cumulonimbus mT
cPcP

44. 3. ________________- occur when a faster moving cold front overtakes a slower moving warm front and lifts the warmer air between the two fronts off the ground
Occluded fronts

45. stationary front
4. ______________- occurs when a warm air-mass and a cold air-mass are side-by-side, with neither air mass moving.
-gentle slope, weather similar to that of a warm front

46. Mid-latitude Cyclones
-Begins when cold air pushes down from the north, changing a stationary front into a pair of warm and cold fronts moving around a low pressure center.
-As the low moves eastward, the cold front
the slower-moving warm front, producing an
overtakes
occluded front

47. Cyclone Animation

48. AC takes hours
D- 3-4 days

49. Warm front would approach and bring 2. Then you would have
Cyclones are “driven” by the heat energy released by condensation (latent heat), causing the low pressure to become even lower, thereby strengthening the winds.
In summer, cyclones move about 800 km a day, while in winter they move about 1,100 km a day. A mid-latitude cyclone may cover as much as one-half of the entire continental United States at one time.
Warm front would approach and bring
2. Then you would have
3. The cold front would arrive with
long, steady rainfall
warm temperatures, high humidity
thunderstorms

50. 2 3 1 1 2 3 City 3 -Temperature increasing -Pressure decreasing City 1
-Long-lasting, light precipitation
City 1
-Temperature decreasing
-Pressure increasing
-Short, heavy precipitation
-Thunderstorms 2 3 1 1 2 3
City 2
-Warm temperature
-Pressure steady
-Humid, but no precipitation

51. Predictions Decreasing air pressure-
Increasing air pressure-
Precipitation, higher humidity, winds, building cloud cover
Clear skies, dry air, lower humidity, calm