1. Weather and Climate
Chapter 3

2. Factors Affecting Climate
Weather is the condition of the atmosphere at a given time and place.
Weather conditions in a geographic region over a long time are called climate.

3. Factors The Sun heats the Earth unevenly.
The tilt of Earth as it revolves around the Sun is very important.
It determines which hemisphere receives the Sun’s most direct rays at a given time of year.
This process causes the changing seasons.

4. What happens to the Sun’s energy when it reaches Earth?
½ is reflected back into space or absorbed by the atmosphere
Earth’s surface absorbs the other ½
Once absorbed, solar energy is converted into heat.
The measurement of heat is called temperature.

5. Global Wind Belts
Some areas of the world have winds that blow from the same direction most of the time. These winds are called prevailing winds.
Doldrums- area with no prevailing winds.
Front occurs when two air masses of different temperatures or moisture levels meet.

6. Weather Factors
evaporation- the process by which water changes from a liquid to a gas.
humidity- the amount of water vapor in the air.
condensation- is the process by which water vapor changes from a gas into liquid droplets.

7. Mountain Effects
Orographic effect- occurs when moist air pushes against a mountain. The barrier forces the air to rise. The rising air cools and condenses, forming clouds and causing precipitation.

8. Rain Shadow
The side of the mountain facing the wind receives a great deal of moisture. This side is known as the windward side.
The side of the mountain facing away from the wind is the leeward side. As the air moves down the leeward side, it warms and dries.
This drier area is called a rain shadow. Deserts are often located in rain shadows.

9. Storms
Hurricanes are the most powerful and destructive tropical cyclones. They begin over warm tropical areas.
Hurricanes are called typhoons in the western pacific can create dangerous high waves.

10. Climate Tropical Humid- is found in areas close to the equator.
Tropical wet and dry- just to the north and south of the tropical humid climate is the tropical wet and dry climate. It is sometimes called the tropical savanna climate.
Arid- most arid, or desert, climate regions are centered at about 30 degrees north and south of the equator.

11. Climate
Semiarid- is a transition zone between the arid climate and the more humid climates.
Mediterranean- exists in two areas….one is along coastal areas of southern Europe. The other is along west coast of continents with cool ocean currents.
Humid Subtropical- is found on the eastern side of continents where there are warm ocean currents.

12. Climate
Marine West Coast- heavily influenced by oceans, is generally found on the west coasts of continents in the upper middle latitudes.
Humid Continental- found in the interiors and east coasts of upper-middle latitude continents.
Subarctic- located generally about 50’ nort latitude.

13. Climate
Tundra- Coastal areas in high latitudes have a tundra climate. They also have long winters.
Ice Cap- found in earth’s polar regions, always covered by huge flat masses of ice and snow.
Highland- can have varying climates b/c temperatures change with elevation.