chapter 3 section 1 powerpoint
TRANSCRIPT
Chapter 3
Section 1
Seasons and Weather
I. SeasonsA.Earth’s Tilt
1. Earth is tilted at a 23.5° angle relative to the sun.
2. Areas of Earth get more, less direct sun at different times of year.
3. The seasons are related to the earth’s tilt and revolution.
4. The solstice marks beginning of summer, winter.
a. sun’s rays directly overhead at noon at furthest points north and south.
5. The equinox marks the beginning of spring and autumn.
a. day and night are equal in length.
Seaso
ns:
N
ort
hern
H
em
isphere
II.WeatherA.Weather and Climate
1. Weather—atmospheric conditions at a particular location and time.
2. Climate—weather conditions at one location over a long period.
a. Example: Northern Russia has a cold climate
B.What Causes the Weather?1. Sun: amount of solar energy received.
2. Water vapor: determines whether there will be precipitation.
3. Precipitation—water droplets falling as rain, snow, sleet, hail.
4. Cloud cover: clouds may hold water vapor.
C.What Causes the Weather?1. Landforms and bodies of water.
a. Water heats slowly, loses heat slowly.
b. Land heats rapidly, loses heat rapidly.
2. Elevation: as elevation increases, air becomes thinner.
a. Thin air cannot hold moisture.
3. Air movement: distributes moisture and solar energy.
D.Precipitation1.Precipitation comes about when:
a.warm air rises, cools, loses ability to hold water vapor.
b.water vapor condenses into droplets.
c. water droplets form clouds.
d.heavy clouds release droplets as rain, snow.
2.Three types of precipitationa. Convectional
b. Orthographic
c. Frontal
3.Rain shadow—land on leeward side of hills, mountains.a. little precipitation in rain shadow.
Conve
nti
onal
Oro
gra
phic
Fronta
l
E.Hurricanes1. Huge storms called hurricanes, or typhoons in
Asia:
a. form over warm, tropical ocean waters.
b. hit land with heavy rain, high winds, storm surge.
F. Tornadoes1. Tornado—a powerful, funnel-shaped column of
spiraling air:
a. from strong thunderstorms.
b. capable of immense damage.
Look at the typhoons in this image and describe how the wind and water appear to be moving?
5 T
hem
es
Regio
n: To
rnado A
lley
“Tornado Alley” is an
example of a formal region,
which is an area defined by
a limited number or related
characteristics. These
characteristics include
topography and weather
patterns. What type of
precipitation would be most
common in Tornado Alley?
III.Weather ExtremesA.Blizzards
1. Blizzard—heavy snowstorm with strong winds, reduced visibility.
B.Droughts1. Drought: long period of time with either no or
minimal rainfall.
C.Floods1. Water spreads out over normally dry land.
Examine the photograph and guess what economic problems might be caused by the drought?