Transcript Chapter Thirteen: Atmosphere and Climate Change

CHAPTER THIRTEEN: ATMOSPHERE
AND CLIMATE CHANGE
Section One: Climate and Climate
Change

What Factors Determine Climate?
 Climate:
the long-term prevailing weather conditions at
a particular place bases upon records taken
 Things





that determine climate
Latitude
Atmospheric circulation patterns
Oceanic circulation patterns
Topography
Solar and volcanic activity
Section One: Climate and Climate
Change

Latitude
 The
distance from the equator measured in degrees
north or south of the equator
 Equator
is at 0˚ latitude
 North Pole is at 90˚ latitude north
 South Pole is at 90˚ latitude south
 Low latitudes: closer to the equator and receive more
sunlight
 High latitudes: closer to the poles and receive less sunlight
Section One: Climate and Climate
Change
Section One: Climate and Climate
Change

Atmospheric Circulation

How the air moves across
the earth
Cold air sinks because it is
denser than warm air (
compresses and warms as
it sinks)
 Warm air rises (expands
and cools as it rises)
 Warm air holds more
water vapor than cold air
(causes fog, rain and
snow)

Section One: Climate and Climate
Change

Atmospheric Circulation
1.
2.


The sun warms the ground
and warms the air above
the ground
Warm air rises, and cooler
air replaces it (wind)
Areas that get more
sunlight have more warm
air that rises and cools.
When it cools it can hold
less water vapor so
precipitation occurs.
Therefore, the more sunlight
an area receives, the more
precipitation it gets.
Section One: Climate and Climate
Change

Atmospheric
Circulation
 Prevailing
Winds:
winds that blow
predominately in one
direction throughout
the year
 To
the right of the
Northern Hemisphere,
or to the left of the
Southern Hemisphere
Section One: Climate and Climate
Change

Oceanic Circulation Patterns
 Water
holds a large amount of heat
 Ocean current movement mostly caused by wind
 El Niño: the short term periodic change in the location
of warm and cold water masses in the Pacific Ocean
 Warm
water is pushed eastward, and rainfall follows
 More rainfall in southern U.S. and South America
 La
Niña: the water in the eastern Pacific Ocean is
cooler than usual
Section One: Climate and Climate
Change
Section One: Climate and Climate
Change

Topography
 Topography:
local geography of the area
 Mountains and mountain ranges influence precipitation
and temperature
Section One: Climate and Climate
Change

Solar and Volcanic Activity
 Sun
 Emits
UV radiation which produces more ozone
 More ozone causes the earth to also warm
 Volcanoes
 Causes
sulfur dioxide to be released
 Sulfur dioxide mixes with water vapor to make haze
 Haze reflects sunlight and causes a global temperature
decrease
Section One: Climate and Climate
Change

Seasonal Changes in Climate
 Seasons
 Causes
are a result of the tilt of the Earth’s axis
a change in the amount of sunlight received
Section Two: The Ozone Shield

Ozone Layer
 Ozone
Layer: an area
in the stratosphere
where ozone is highly
concentrated
 Chemicals that cause
Ozone Depletion
 CFCs:
human made
chemicals that destroy
ozone molecules

Also causes a problem
in the bird population
Section Two: The Ozone Shield

The Ozone Hole
 Ozone
Hole: a thinning of stratospheric ozone that
occurs over the poles during the spring
Section Two: The Ozone Shield

The Ozone Hole
 Polar
Stratospheric Clouds: high altitude clouds made
of water and nitric acid
 Where
CFCs are converted to chlorine
 Chlorines are broken apart by UV
 Chlorines destroy the ozone
Section Two: The Ozone Shield

The Ozone Hole
 Effects
 More
on Humans, Animals, and Plants
UV radiation can pass through the atmosphere
 UV damages DNA and can cause skin cancer
 Kills phytoplankton
 Kills amphibian eggs
 Interfering with photosynthesis
Section Two: The Ozone Shield

Protecting the Ozone Layer
 Montreal
Protocol: nations agreed to limit their
production of CFCs
 United
States pledged to ban all substances that harm the
ozone by 2000
Section Three: Global Warming

The Greenhouse Effect
 Greenhouse
Effect: caused by atmospheric gases radiating
and not absorbing hear causing the gradual warming of the
Earth

Greenhouse gases
 Water Vapor
 Carbon Dioxide
 CFCs
 Methane
 Nitrous Oxide
Section Three: Global Warming

The Greenhouse Effect
 Carbon
dioxide level
decrease in the
summer and increase in
the winter
 Photosynthesis
removes
carbon dioxide from
the atmosphere
 Carbon
dioxide levels
are steadily rising
Section Three: Global Warming

Global Warming
 Global
Warming: the increase in the average
temperature at Earth’s surface
Section Three: Global Warming

Consequences of a
Warmer Earth
Melting Ice and Rising
Sea levels
 Global Weather Patterns
Change
 Human Health Problems
 Droughts Killing Crops
 Shifts Geographical
Ranges of Plants and
Animals

Section Three: Global Warming

Recent Findings
 Temperature
has increase 0.6˚C
 Snow cover and ice have decreased
 Average global sea level has risen

Reducing the Risk
 Kyoto
Protocol: required developed countries to
decrease emissions of carbon dioxide and other
greenhouse gases by an average of 5% below their
1990 levels by 2012