Factors which influence
climate
Today’s Aim 1. To learn the how mountains affect climate.
Keywords
Latitude, Equator, Altitude.
How Mountains that affect
CLIMATE
Brainstorm the factors
which you think Mountains
affect climate in your
journal– discuss with
people around you.
Mountains
SPI 0507.8.2 Explain
how mountains affect
weather and climate.
Three Ways
In this PowerPoint you are going to
study three ways mountains affect
climate.
– Elevation
– Rain Shadows
– Mountain and Valley Breezes
How Mountains Affect
Weather & Climate
Number 1 - Elevation
Have you ever noticed as you are
driving into what happens when you
drive up a mountain?
What is the difference between climate
and weather?
What is climate?
1
Climate
• Climate is the pattern of weather that occurs
in an area over many years. It determines the
types of plants or animals that can survive,
and it influences how people live.
• Climate is determined by averaging the
weather of a region over a long period of
time, such as 30 years.
What is climate?
1
Latitude and Climate
• Latitude, a measure
of distance north or
south of the equator,
affects climate.
• The tropics—the region
between latitudes
23.5°N and 23.5°S—
receive the
most solar radiation because the Sun
shines almost directly over these areas.
What is climate?
1
Latitude and Climate
• The polar zones
extend from 66.5°N
and 66.5°S latitude
to the poles. Solar
radiation hits these
zones at a low angle,
spreading energy
over a large area.
• Polar regions are never warm.
What is climate?
1
Latitude and Climate
• Between the tropics
and the polar zones
are the temperate
zones. Temperatures
here are moderate.
Most of the United
States is in a
temperate zone.
How many times have you seen snow
on the top of mountains when there
was none in the city below?
The reason for this is the elevation.
Mountain City has the highest
elevation of any city in Tennessee at
2350 feet above sea level. The
highest point in Johnson County is
Snake Mountain at an elevation of
5574 feet above sea level.
Elevation
 The
higher the elevation, the lower
the temperature becomes.
 The rate at which the temperature
drops is known as the lapse rate.
On average, the lapse rate is 3.6
degrees per 1,000 feet.
Elevation Differences
 With
Snake Mountain over 2000 feet
higher in elevation than Mountain
City, the temperature on top of
Snake Mountain could easily be 7
degrees cooler.
How Mountains Affect
Weather & Climate
Number 2 - Rain Shadows
What is climate?
1
Mountains
• At the same
latitude, the
climate is
colder in the
mountains
than at sea
level.
• When radiation from the Sun is absorbed by
Earth’s surface, it heats the land.
What is climate?
1
Mountains
• Heat from
Earth then
warms the
atmosphere.
• Because
Earth’s
atmosphere
gets thinner at higher altitudes, the air in the
mountains has fewer molecules to absorb heat.
What is climate?
1
Rain Shadows
• On the windward side of a mountain range,
air rises, cools, and drops its moisture.
• On the leeward side of a mountain range air
descends, heats up, and dries the land.
Windward Vs. Leeward
• Rainfall occurs on the windward side of the
mountain where the air is rising.
• Cool & Wet
• It is dry on the leeward side of
the mountain where the air is sinking.
• Warm & Dry
Rain Shadows
Mountains greatly affect the climate.
They act as barriers blocking rain and
wind.
What do you think a rain shadow is?
One side of the mountain may have a
very different climate from the other
side. In some cases mountains
create a shadow. This is where rain
does not fall. Deserts can form in
the rain shadow regions.
Animations
http://www.mhhe.com/biosci/genbio/tlw3/
eBridge/Chp29/animations/ch29/rain_sha
dow_formation.swf
 http://bio1100b.nicerweb.com/med/Vid/Di
scover2e/ch39a04_RainShadow.swf
 http://www.uky.edu/AS/Geology/howell/g
oodies/elearning/module07swf.swf
 http://www.mrphome.net/mrp/rainshado
w.swf

Example – Rain Shadow
Death Valley in the United States is
behind the Pacific Coast Ranges of
California and the Sierra Nevada
range.