1. Unit 12: The Atmosphere& Weather (Part 2)15
CHAPTER
Unit 12: The Atmosphere& Weather (Part 2)

2. Air Pressure & Wind

3. Force Weight of the Air What is air pressure?
Air (Atmospheric) Pressure: the _______ exerted by the _____________________ above it
Weight of the Air

4. Decreases Air Pressure
As you move through the atmosphere you will experience a gradual change in pressure
Pressure slowly _____________ the farther you go up
Decreases

5. Higher Higher Air Pressure Mercury Barometer Measuring Air Pressure:
Lesson 15.1 Earth’s Atmosphere
Air Pressure
Measuring Air Pressure:
______________________ – air pressure pushes a column of mercury upward in a tube. The __________ the air pressure, the __________ the mercury rises
Mercury Barometer
Higher
Higher
Barometer

6. bending dial Aneroid Air Pressure Measuring Air Pressure:
Lesson 15.1 Earth’s Atmosphere
Air Pressure
Measuring Air Pressure:
_________ Barometer – walls bend in and out based on air pressure. The ____________ of the chamber causes a ______ to move which indicates a change in pressure.
Aneroid
bending
dial

7. Why does air pressure matter?
Why do places have different air pressures?
_____________________ creates air pressure differences
Solar Radiation

8. Why does air pressure matter?
Wind
______ is created because air flows from an area of _______ pressure to an area of _______ pressure
High
Low

9. Cold Air Sinking Clockwise Northern good
High and Lows
Areas of High pressure are characterized by:
______________________
Winds blowing away in _______________ motion (in ______________ Hemisphere)
Leads to “__________” weather
High Pressure = _______________
Cold Air Sinking
Clockwise
Northern
good
Anti-cyclone

10. Clouds & Precipitation
High and Lows
Areas of Low pressure are characterized by:
____________________
This leads to ___________________________
Winds rotate in a _________________________ motion (in ___ Hemisphere)
Low Pressure = __________
Hot Air Rising
Clouds & Precipitation
Counterclockwise N.
Cyclone

12. Pressure Differences Coriolis Effect
Factors of Wind
What makes some places windier than others?
Two factors:
1) ____________________________
2) _____________________
Pressure Differences
Coriolis Effect

13. Greater Greater Wind Speed
Factors of Wind
1) Pressure Differences
Wind is caused by differences in air pressure.
The ___________ the difference the ____________ the
________________.
Greater
Greater
Wind Speed

14. Isobars Equal closer High winds Low Winds
Factors of Wind
Isobars
__________ are connected lines of _______ pressure
The spacing between each isobar indicates pressure change
The _________ the lines of an isobar are together, the steeper the pressure gradient (changes in pressure)
Close Isobars= _______________
Widely Spaced Isobars= _________
Equal
closer
High winds
Low Winds

15. Where is it windier, Raleigh, NC or Louisville, KY?
Factors of Wind
Where is it windier, Raleigh, NC or Louisville, KY?

16. Rotation Right Left Faster Stronger
Factors of Wind
2) Coriolis Effect
The ____________ of the Earth deflects wind direction
In the Northern Hemisphere to the _____
In the Southern Hemisphere to the _____
The ________ you move the ______________ the effect
Rotation
Right
Left
Faster
Stronger

17. Without Coriolis Effect
With Coriolis Effect

18. Without Coriolis Effect
With Coriolis Effect

19. No, its too small of a scale
Factors of Wind
Does the Coriolis effect have an impact on toilet water in each hemisphere?
No, its too small of a scale

20. 2 Cells Heating Sunlight rises Dense Toward the poles Global Winds
Winds caused by uneven ____________ of Earth’s atmosphere.
Equator gets more direct ______________
Equatorial air expands, _______ and flows ________________
Polar air is more __________ so it flows toward the equator
Non-rotating Earth, ________ (North & South)
Heating
Sunlight
rises
Toward the poles
Dense
2 Cells

21. Six East West East Global Winds
Due to the Earth’s rotation, instead of two cells you have _______.
Why do we have six?
High pressure around 30° and low pressure around 60°
___________________
Three winds in each hemisphere
Trade winds – blow from the ______
Westerlies – blow from the _______
Polar Easterlies – blow from the _______
Six
High Pressure Sinks
Low Pressure Rises
East
West
East

23. Jet Stream West to East Polar Subtropical
Global Winds
Jet Stream
_____________ – a fast flowing current of air located between 5-7 miles above the surface of the Earth
In the northern hemisphere they flow from _______________
_______ Jet Stream is found at 60° and the _______________ jet stream is found at 30°
Can move at speeds of more than 275 mph
West to East
Polar
Subtropical

25. Air masses & Fronts

26. High Low Air Masses High Low Where they form
Wind
Wind is the movement of air from places of _______ pressure to places of ______ pressure
Wind moves in large masses called ________________
Air masses also move from areas of ______ pressure to areas of _______ pressure
These air masses retain the characteristics of ____________________
High
Low
Air Masses
High
Low
Where they form

28. Moisture Dry Wet Temperature Warm Cold Coldest
Types of Air Masses
Air masses can be described in two ways
1) ______________
Continental (_____ air) vs. Maritime (______ air)
If the air mass forms over land or water determines if it carries a lot of moisture or not
2) __________________
Tropical (_________ air) vs. Polar (______ air) vs. Arctic (___________ air)
The temperature of the air mass depends on if it formed closer to the equator or closer to the poles
Moisture
Dry
Wet
Temperature
Warm
Cold
Coldest

29. Putting it all together
Continental
Maritime
Tropical
Continental Tropical:
Maritime Tropical:
Polar
Continental Polar:
Maritime Polar:
Arctic
Continental Arctic:
Knowing moisture and temperature, what would the characteristics be of…
Continental Polar (cP)?
Maritime Tropical (mT)?
Continental Arctic (cA)? cT mT
Cold & Dry cP mP
Warm & Wet cA
Very Cold & Dry

30. MAKE SURE YOU TALK ABOUT THESE
MAKE SURE YOU TALK ABOUT THESE! MUST BE ABLE TO IDENTIFY THAT SOUTH EASTERN STATES ARE GETTING AIR MASS mT ON A MAP!

31. Warmer, less dense air is always forced up
Fronts
Front
_________ – the boundary between two different _________________
Along a front, ____________________________________
4 types of fronts
___________
______________
_______________
Air Masses
Warmer, less dense air is always forced up
Warm
Cold
Stationary
Occluded

32. Red semi-circles Warm Front Warm air slowly moves into Long time
A warm front occurs when ______________________________ _______ an area covered by cooler air.
Takes a ______________ for warm air to displace colder air
Marked by long and steady rain
__________________________ are symbols for warm front
into
Long time
Red semi-circles

35. Heavy Precipitation/ Thunderstorms
Cold Front
Cold, Dense Air Quickly
A cold front forms when _______________________ moves into an area occupied by warm air
Compared to speed of warm front, cold fronts move _________________
Marked by ____________________________________ for a short period of time
______________________ are symbols for cold front
Very Fast
Heavy Precipitation/ Thunderstorms
Blue Triangles

38. Not Moving Towards Stationary Front Red semi-circles Blue Triangles
If fronts are _______________________________ each other
Mild precipitation can occur on a stationary front
___________________ on one side, ____________________ on other
Red semi-circles
Blue Triangles

40. Faster Heavy Rain Occluded Front purple Same direction Overtakes
Cold fronts move _______________ than warm fronts
When an active cold front _______________ a warm front, an occluded front forms
This will force the warm front up into the air, which will lead to _________________________
Usually marked by ______________ semi-circle and triangles in _________________
Overtakes
Heavy Rain
purple
Same direction

43. Severe Weather

44. Lightening, Thunder, Strong Winds & Rain
Thunderstorms
Thunderstorms- a violent weather event accompanied by _________________________________________
Lightening, Thunder, Strong Winds & Rain

45. 4,000 Warm, Humid Colder Thunderstorms
There are ~ ___________ thunderstorms per day worldwide
Thunderstorms form when __________________ air rises into (above) _________ air in an unstable environment
Warm, Humid
Colder

46. There are two kinds of thunderstorms: Cold front and Warm air

47. Up & Over Spring & Fall Thunderstorms Cold Front Thunderstorm
Warm air is pushed ______________ cold air
Strong and last for several hours.
Mostly in _____________________.
Can also have tornadoes and hail.
Up & Over
Spring & Fall

49. Uneven Heating summer Thunderstorms Warm Air Thunderstorm
Caused by ______________________ of Earth’s surface
Less violent and usually last less than hour
Usually occur in __________
Uneven Heating
summer

50. Cumulus Updrafts Thunderstorm Stages
1) __________: strong ___________ blow warm, moist, air higher until the vapor condenses, forming a cumulus clouds
Updrafts

51. Mature Downdrafts cumulonimbus Thunderstorm Stages
2) _________: violently rising, warm air forms ________________ clouds
Updrafts continue and ______________ begin as rain starts to fall
Thunder and lightning begin
cumulonimbus
Downdrafts

52. Dissipating Stop decreases
Thunderstorm Stages
Dissipating
3) ________________: strong downdrafts ________ warm, moist air currents from rising.
Water vapor supply suddenly __________ so the cell dies down
If the storm passes over new areas of warm water then new cells can begin again
Stop
decreases

53. No one actually knows exactly what causes lighting but…
Lightning
No one actually knows exactly what causes lighting but…

54. Dissipation Electrical Charge
Lightning
What causes lightning?
Simple Answer: The ________________ of ___________________.
Dissipation
Electrical Charge

55. Water & Ice Electrons Lightning Collect descending
What causes lightning?
___________________ particles move quickly through a cumulonimbus cloud by updrafts and downdrafts
The particles interact and exchange energy
________________ are sheared off of ascending particles and they ______________ on the _________________ particles
Water & Ice
Electrons
Collect
descending

56. Negative Bottom Positive Top
Lightning
What causes lightning?
_______________ charges collect near the _____________
_______________ charges near the _______.
Negative
Bottom
Positive
Top

57. Positive Ground Below Lightning What causes lightning?
The negative bottom of the cloud induces a collection of _____________ charge on the _____________________
Positive
Ground Below

58. Streamer Meet Stepped Leader Lightning Return Stroke Brightest Flash
A negatively charged _______________________ comes from the cloud down
The object that is about to be stuck sends a positive “_______________” up to meet the leader
When the two paths __________, electricity moves down the path to the ground and a __________________ is sent back into the sky and causes the _________________ of the lightning
It all happens so quickly so we can’t really see the different parts without an awesome camera!
Slow Motion
Streamer
Meet
Return Stroke
Brightest Flash

59. Lightning

62. 50,000°F expands compresses Sound waves Bounce off Shock wave
Thunder
50,000°F
As electricity flows through the air it raises the temperature to ______________
This rapidly ________________ and _____________________ the surrounding air which produces a _______________
The shock wave produces ________________________ that we hear as a crack of thunder
We hear thunder rumble as the initial sound waves _____________________ of other things and because they begin at ______________________________ away from us
expands
compresses
Shock wave
Sound waves
Bounce off
Different distances

63. Faster Thunder the speed of light = 670,616,629 miles per hour
Light travels _________ than sound so we see lightning before we hear any sound
Faster
the speed of light =
670,616,629 miles per hour
The speed of sound =
761 miles per hour

64. Thunder is the _________ of lightning!!
Result

65. High Low Low Pressure Tornadoes
A rapidly spinning column of air that has _________ winds, _______ pressure and touches the ground.
The center of a tornado is characterized by its ________________
High
Low
Low Pressure

66. Super cells Tornadoes Unstable conditions Wind Shear
Often associated with very strong thunderstorms called _______________
Scientists don’t know exactly what causes tornados but they know that these conditions are necessary:
____________________________ – unusually warm, wet lower air and colder upper air
___________________ – wind speed increasing and direction changing with altitude
Ex. southerly wind of 15 mph at the surface, changing to a southwesterly or westerly wind of 50 mph at 5,000 feet altitude
Super cells
Unstable conditions
Wind Shear

67. Horizontal Updraft Clouds
How to form a tornado
Horizontal
1. _________________ rolling winds are created
2. Rolling winds hit an _______________ and start to tilt upward.
3. Rotating winds now in _____________
4. Rotating winds can touch down and form tornadoes
Updraft
Clouds

68. How to form a tornado

69. Warm, Humid Hot, Dry Cool, dry
Tornado Alley
Tornado Alley occupies a unique geographic position where ________________ air from the Gulf of Mexico, _______________ air from Arizona and New Mexico, and _____________ air from Canada meet
Warm, Humid
Hot, Dry
Cool, dry

70. Tornado Alley

71. Tornado Intensity: EF0 – EF5
Measured on the Enhanced __________ Tornado Intensity Scale
Measures how much ______________ is done by the tornado and wind speed
Fujita
damage

73. Tornado Warning System
Watch
Warning
Conditions are _____________ to the development of tornadoes in and close to the watch area.
_________ area
Can last 3-5 hours
A tornado has been ___________ by spotters or indicated on radar and is occurring or imminent in the warning area.
__________ area
Can last 30 min – 1 hour
conducive
Sighted
Large
Small

74. http://www. outsideonline

75. Hurricanes

76. 74 mph Hurricanes low Counterclockwise Typhoons Cyclones
Whirling tropical cyclones that produce sustained winds of at least __________ or kph.
Center of _______ pressure
Rotate ____________________ in the N. Hemisphere
Hurricanes go by different names in other parts of the world, these severe tropical storms can be called:
In the Pacific they are called ____________
In the Indian Ocean they are called __________
74 mph
low
Counterclockwise
Typhoons
Cyclones

78. Hurricane Anatomy

79. Eye Eyewall intense Calmest Parts of a Hurricane
______ – center of the hurricane
___________ and warmest part of the storm.
_____________ – Thick clouds surrounding the eye with the most ____________ winds of the hurricane
Calmest
Eyewall
intense

80. 38 39-73 74 Storm Stages of a Hurricane Disturbance Depression
Tropical ______________ - is the first stage of consisting of a mass of thunderstorms that have only a slight wind circulation.
Tropical _____________ - whirling area of low pressure and storm activity with sustained winds _____ mph or less.
Tropical ________ - sustained winds ____ ___ mph. This is the stage when the storm is given a name.
Hurricane – winds at or over ____ mph
Depression 38
39-73
Storm 74

82. Greatest Damage Strong winds Drowning
Storm Surge
Greatest Damage
________________________ from hurricanes comes from the storm surge.
Storm Surge - a combination of high tide and water that is pushed onshore by the _________________ of a hurricane; can produce surges meters.
Most deaths from hurricanes are by _____________ due to the storm surge.
Strong winds
Drowning

83. http://video. nationalgeographic

84. Hurricane Classification
Hurricanes are classified according to intensity using the Saffir-Simpson scale
Category
Sustained Winds
(mph)
Surge (ft)
Damage 1
74-95
4-5
Minimal 2
96-110
6-8
Moderate 3
9-12
Extensive 4
13-18
Extreme 5
156+
19+
Catastrophic
Hurricane Watch: issued several days before landfall
Hurricane Warning: issued 24 hours before landfall

85. Naming and Forecasting hurricanes
Female
ABC
1953: names were ___________ and in _______ order
1979: began alternating ______________________ names
The list of names was created by the World Meteorological Society and names are recycled every _____________
EXCEPTION: If a hurricane was particularly destructive or noteworthy, the name will be ___________ and replaced on the list with another name beginning with the same letter
Hurricane season in the South East US is _________________________
The interaction between ocean water temperatures and warm air masses contributes to the formation of hurricanes during the late summer
Male & Female
6 years
retired
June - November

88.
A tornado is a violently rotating column of air that extends from the bottom of a cumuliform cloud, such as a thunderstorm, to the ground. Tornadoes are often (but not always) visible as a funnel cloud. It is important to never confuse a tornado with ahurricane or other tropical cyclone because tornadoes and hurricanes are very different phenomena. Perhaps the only similarity between tornadoes and hurricanes is that they both contain strong rotating winds that can cause damage.
There are many differences between tornadoes and hurricanes. The largest tornado every observed was 4 km (2.5 mi) wide, and most tornadoes are < 0.8 km (0.5 mi) wide. The parent storm clouds that produce tornadoes are generally about 16 km (10 mi) wide. Hurricanes, however, are typically much larger, ranging from about 160 km (100) mi to 1600 km (1000 mi) wide (see Hurricane Structure and Primary Circulation). A tornado’s lifetime is short, ranging from a few seconds to a few hours. By contrast, a hurricane’s lifecycle can last from days to weeks. Tornadoes, and the parent storm clouds that produce them, require strong vertical wind shear and strong horizontal temperature changes to form and survive; hurricanes thrive in regions of weak vertical wind shear where the horizontal change in atmospheric temperature is small (see Hurricane Genesis: Birth of Hurricane). Also, strong tornadoes usually occur over land, while hurricanes almost always form over the ocean. Finally, the strongest tornadoes can have wind speeds over 483 kph (300 mph), but even the strongest hurricanes rarely produce wind speeds over 322 kph (200 mph).

89. What is the relationship between barometric pressure and the storm stage?