1. Meteorology

2. Heat and Weather Patterns
Weather climate
visible light air masses
sea breeze Convection currents
Density land breeze

3. Heat and Weather Patterns
What is weather?
What is climate?
What is a sea breeze?
What is a land breeze?
What are air masses?

4. Heat and Weather Patterns Weather and Climate
Weather is the process in the atmosphere that changes over a short period of time.
Climate is the weather that is in place most of the time or over a long period of time.
Is it Climate or Weather?
What’s the weather like most of the time where you live?

5. The Sun’s Energy
Nearly all the energy in Earth’s atmosphere comes from the sun.
Most of the energy from the sun reaches Earth in the form of visible light and infrared radiation, with a small amount of ultraviolet radiation.
Visible light is energy you can see.

6. The Sun’s Energy Earth changes infrared radiation into heat energy.
Ultraviolet radiation causes sunburns, skin cancer, and eye damage.
Some of the sun’s energy reaches Earth’s surface and is reflected back into the atmosphere.
Some of the energy is absorbed by the land and water and changed into heat.

7. The Sun’s Energy Land heats up and cools down faster than water.
Water heats up more slowly than land does, but holds the heat longer.
Air heats up unevenly.
Warm air becomes less dense and rises.
Cooler air becomes more dense and sinks.

8. The Sun’s Energy
Wind that blows from an ocean or lake onto land is known as a sea breeze.
The flow of air from land to a body of water is called a land breeze.
Convection currents transfer heat from one place to another through a liquid or a gas.
In Earth’s atmosphere, convection currents carry warm air upwards and cool air downwards.
This is because of the uneven heating of Earth’s surface.

9. The Sun’s Energy
Huge chunks of warm and cold air are called air masses.
Air masses move sideways across continents and oceans.
Clouds and storms form when these masses run into each other.
When a cold air mass meets a warm air mass, thunderstorms may appear.

10. Quick Check Land absorbs radiation from the sun A. slower than water.
B. faster than water.
C. at the same rate as water.
D. almost never.

11. Quick Check In the atmosphere, what happens in a convection current?
A. cool air and warmer air both rise
B. cool air and warmer air both fall
C. cool air rises and warmer air falls
D. cool air falls and warmer air rises

12. Quick Check What does solar (infrared) radiation produce on Earth?
A. light
B. heat
C. land
D. water

13. Quick Check In which direction does a sea breeze move?
A. toward the land
B. toward the sea
C. up
D. down

14. Quick Check How are climate and weather alike?
A. They both occur over short periods of time.
B. They both occur over long periods of time.
C. They both are affected by radiation from the sun.
D. They are both caused by even heating of Earth’s surface.

15. Global Wind Systems and Weather Events
Global Winds Tornadoes
Thunderstorms Cumulonimbus clouds
Low density High density
Low pressure High pressure
Air pressure

16. How would you distinguish between local winds and global winds?
What combination of air produces global winds?
What makes global winds curve rather than move in straight lines?
What properties of air near the ground are likely to produce a thunderstorm?
What combination of properties describes cold air?

17. Global Winds
Wind is the horizontal movement of air from an area of high pressure to an area of low pressure.
All winds are caused by differences in air pressure.
Local winds are winds that blow over short distances.
Local winds are caused by unequal heating of Earth’s surface within a small area.

18. Global Winds
The unequal heating of Earth’s atmosphere by sunlight produces global winds.
The combination of high-pressure polar air and low-pressure equatorial air produces global winds.
The angle at which sunshine strikes Earth’s surface in MAINLY responsible for the unequal heating of Earth’s surface.

19. Global Winds
Air moves from areas of high pressure to areas of low pressure.
Dense, high-pressure air over the poles sinks and moves towards the low-pressure air over the equator.
Less dense, low-pressure air over the equator rises and moves toward the poles.
These movements of air are global winds.
Earth’s spin on its axis makes these winds move along a curved path (Coriolis effect).
Northern Hemisphere global winds curve clockwise.
Southern Hemisphere global winds curve counterclockwise.

20. Tornadoes and Thunderstorms
Differences in air pressure can also produce powerful local winds and storms.
The low density, warm air will form clouds when it reaches colder air in the sky.
As low density moisture rises high in the sky, it may freeze into particles that are electrically charged.
These charged particles can produce lightning and thunder.

21. Tornadoes and Thunderstorms
Moist, low pressure air near the ground produce thunderstorms.
Thunderstorms form within large cumulonimbus clouds, also known as thunderheads.
Tornadoes are swiftly turning, very low-pressure funnels or air. They produce the fastest moving winds on Earth.
Tornadoes develop in low, heavy cumulonimbus clouds.
Most likely to occur in spring and summer , often in the late afternoon when the ground is warm.
Tornadoes occur more often in the U.S. than in any other country.

22. Quick Check What combination produces global winds?
A. low-pressure polar air and low-pressure equatorial air
B. low-pressure polar air and high-pressure equatorial air
C. high-pressure polar air and high-pressure equatorial air
D. high-pressure polar air and low-pressure equatorial air

23. Quick Check
What is MAINLY responsible for the unequal heating of Earth’s surface?
A. the distance of the sun from different parts of Earth
B. the angle at which sunshine strikes Earth’s surface
C. the material on Earth’s surface
D. changes in the amount of energy the sun puts out

24. Quick Check
What makes global winds curve rather than move in straight lines?
A. differences in air pressure
B. differences in density
C. differences in temperature
D. Earth’s rotation on its axis

25. Quick Check
What properties of air near the ground are likely to produce a thunderstorm?
A. moist, low pressure
B. dry, low pressure
C. moist, high pressure
D. dry, high pressure

26. Quick Check Which combination of properties describe cold air?
A. high density and low pressure
B. low density and low pressure
C. high density and high pressure
D. low density and high pressure

27. Heat and Weather Patterns
Tropical storms Hurricanes
Tropical depression
Clockwise Counterclockwise
Eye of a hurricane

28. How does evaporation of water affect weather and the formation of hurricanes?
What is the source of a hurricane’s energy?
What is the general name for a powerful tropical storm?
Where are tropical storms born?
What happens when moist air rises high into the sky?

29. Moisture and Weather Patterns
Tropical storms are born over warm water near the equator.
Very large and powerful tropical storms with spinning winds are called tropical cyclones.
In the Atlantic Ocean and the eastern Pacific Ocean, tropical cyclones are called hurricanes.
In the northwest Pacific Ocean, they are called typhoons.

30. Moisture and Weather Patterns
Energy from the sun warms ocean water.
Energy absorbed by the ocean water causes the water on the surface to evaporate.
The warm, evaporated water rises.
This produces an area of low pressure called a tropical depression.
This is when clouds begin to form.

31. Moisture and Weather Patterns
The air in the center of a depression in the Northern Hemisphere begins to spin counterclockwise.
In the Atlantic Ocean, global winds push the storm westward.
As the storm continues to move over warm water, heat from the water feeds it.
As its air pressure drops lower its winds move faster and faster.

32. Moisture and Weather Patterns
A hurricane has a typical shape.
The eye of a hurricane is a place of very low pressure with no clouds above it.
In the eye, it is very calm and sunny.
The most violent winds in a hurricane form the wall of the hurricane’s eye.
Eventually, a hurricane will travel over cooler water or land.
Once this happens, the hurricane can no longer feed on heat energy from warm water.

33. Quick Check What is the source of a hurricane’s energy?
A. warm, moist air evaporating from the sea
B. cool, moist air evaporating from the sea
C. warm, dry air evaporating from the sea
D. warm, moist air condensing from the sea

34. Quick Check The general name for a powerful tropical storm is a
A. tropical depression.
B. tropical cyclone.
C. hurricane.
D. typhoon.

35. Quick Check Where are tropical storms born?
A. over water near Earth’s poles
B. over land near Earth’s poles
C. over water near the equator
D. over land near the equator

36. Quick Check What happens when moist air rises high into the sky?
A. It cools and evaporates
B. It cools and condenses, forming clouds
C. It warms and evaporates
D. It warms and condenses

37. Quick Check The eye of a hurricane has A. low pressure and high winds.
B. low pressure and no winds.
C. high pressure and high winds.
D. high pressure and no winds.