Download Chapter 2, Section 1

Chapter 2, Section 1
I. Climates and Ecosystems
A. Weather and Climate
i. Weather
a. The condition of the bottom layer of the
earth’s atmosphere in one place over a short
period of time.
b. Descriptions usually mention temperature,
moisture or precipitation, and wind.
1. ex. “Warm, Dry and Calm” or “cold,
snowy and windy.”
ii. Climate
a. The term for the weather patterns that
an area typically experiences over a long
period of time.
b. The climate of an area depends on
elevation, latitude, and location in relation
to nearby landforms and bodies of water.
“Climate is what you expect, weather is what you get. “
B. The Sun and the Earth
i. The Sun, is the source of the earth’s climates
and life on earth.
ii. The Greenhouse Effect
a. Traps the suns radiation to keep earth
warm.
iii. Rotation and Revolution
a. Rotation
1. Earth’s movement on its axis.
b. Revolution
1. Earth orbits the sun.
2. One complete orbit every year is a
revolution.
Rotation
Left Side:
Light from Sun =
daytime
Earth is constantly rotating on its axis.
Right Side:
Dark/No Sun =
Nighttime
Revolution
While rotating on
its own axis, the
earth is also
orbiting the sun.
3. Earth’s tilt means sunlight strikes different
parts of the planet more directly at certain times
of the year.
When North Pole is tilted towards sun, the sun’s
rays fall more directly on the Northern Hemisphere,
bringing longer, warmer days. = AKA Summer in the
Northern Hemisphere and Winter in the Southern
Hemisphere.
Changes in season marked by summer and winter
solstices.
C. Distributing the Sun’s Heat
i. Heat from suns rays does not stay in place.
a. Convection helps distribute heat in air and water.
b. Movements of air are called winds.
c. Movements of water are called currents.
ii. Wind
a. Pattern of winds begins when light, warm air
rises from the Equator and flows northward
and southward toward the poles.
b. Air from cool regions move toward equator.
D. Precipitation
i. Humidity – amount of water vapor contained
in the atmosphere.
ii. Warm, less-dense air absorbs more moisture
than cool air. When this air cools, it cannot
contain all of its water vapor. Forms liquid.
iii. Geographers divide precipitation into three
types:
a. Convectional Precipitation
b. Orographic Precipitation
c. Frontal Precipitation
a. Convectional Precipitation
1. Occurs when hot, humid air rises from the
earth’s surface and cools, thereby losing its
ability to hold much water.
2. Common near equator and tropical areas,
where hot, humid surface air exists.
b. Orographic Precipitation
1. Occurs when warm, moist air is forced upward
when passing over high landforms, causing
precipitation.
2. Common on seacoasts where moist, ocean
winds blow toward coastal mountains.
3. Warm winds cool as they rise up mountains,
clouds form, precipitation occurs, wind is cool
and dry by the time it reaches the other side of
the mountain.
4. This dry, hot air often creates dry climates
behind coastal mountains. Ex. California’s
Mohave Desert lies inland behind the Sierra
Nevada.
c. Frontal Precipitation
1. Occurs when two fronts (air masses) of
different temperatures meet.
2. Warm air is forced upward by the heavier,
cool air.
3. Rising warm air cools, and frontal
precipitation occurs.
E. Other Influences on Climate
i. Temperature and Precipitation are the major
influences on climate.
ii. Other influences include:
a. Nearby Bodies of Water
b. Elevation
c. Nearby Landforms
a. Nearby Bodies of Water
1. Water temperature changes slowly compared
to land.
2. Ocean surface temperature varies only 10
degrees throughout the year.
3. Winds that blow over large bodies of water
take on the water’s temperature. Winds
moderate land temps as they blow on shore.
ex. Marine Climates
Always seems to rain in ________?
b. Elevation
1. Mount Kilimanjaro is located on the Equator
in Tanzania, Africa.
2. However, it is capped by snow year-round.
3. The mountains elevation is 19,341 feet above
sea level. This affects its climate much more
than does its location in the tropics.
c. Nearby Landforms