Transcript Factors that Influence Climate

Factors that Influence Climate
3 main factors:
1. Latitude
• Distance from the
equator
• Angle of suns rays
– Why do we have
seasons?
Latitude
•
• Latitude is at
work here; what
other factors?
• Patterns?
• Temperature
Animation
Factors that Influence Climate
3 main factors:
1. Latitude
2. Altitude
Temperatures fall by 6 °C with every 1000 m
gained in elevation
Altitude
• Often said that:
``altitude mimics latitude’’
What does that mean?
Swiss Alps
http://traumwerk.stanford.edu/archaeolog/2005/12/some_effects_of_altitude_and_c.html
Factors that Influence Climate
3 main factors
1. Latitude
2. Altitude
3. Oceanic
Circulation
• currents
Ocean circulation
• Global conveyor
– Including surface currents such as Gulf stream
that influence climate
El niño
View animations
Factors that Influence Climate
3 main factors
1. Latitude
2. Altitude
3. Oceanic Circulation
Other important factors
• Atmospheric
Circulation
• Winds
• Cold air sinks
– Compresses and warms
• Warm air rises
– Expands and cools
Atmospheric circulation
• Arrows show
direction of winds
near ground
• Winds are angled
because of Earth’s
rotation (coriolis
effect)
• Air at 60 deg N and
S rises, most going
toward the poles,
where it gets cold
and sinks. So, poles
are cold and dry.
Factors that Influence Climate
3 main factors
1. Latitude
2. Altitude
3. Oceanic Circulation
Other important factors
• Atmospheric Circulation
• Solar activity
Radiation Animation
• Solar maximum
– 11 year cycle
Factors that Influence Climate
3 main factors
1. Latitude
2. Altitude
3. Oceanic Circulation
Other important factors
• Atmospheric Circulation
• Solar activity
• Volcanic activity
• Lots of ash and CO2
• O2 and water create
atmospheric haze
volcanoes
•
sulfur dioxide can remain in atmosphere for 3 years,
forming haze that reflects sunlight, cooling the planet
• Mt. Pinatubo in 1991 had that affect
• 1815: Mt. Tambora erupts
• 1816: Year without a summer
Factors that Influence Climate
3 main factors
1. Latitude
2. Altitude
3. Oceanic Circulation
Other important factors
• Atmospheric Circulation
• Solar activity
• Volcanic activity
• Topography
• Shape of the land
• Rain shadow
How does the Earth
gain heat?
• The Sun
What accounts for the Earth’s
temperature?
• Energy balance
– Electromagnetic energy (light, UV, IR) from the
Sun enters the Earth’s atmosphere
– Electromagnetic energy is radiated back to space
3 ways
for transfer of heat energy
• Radiation: electromagnetic waves (such as
light from the sun) travel through space
• Convection: warm gases or liquids rise, cool,
and fall
• Conduction: warm body transfers heat directly
to a colder body
Earth’s Greenhouse Effect
The greenhouse effect
• One of the main reasons Earth has a livable climate
• Not in doubt
• Greenhouse gases: ``Trap’’ heat that is radiated from
the earth’s surface and re-radiate it.
–
–
–
–
Water vapor – main greenhouse gas
Carbon dioxide
Methane -- 26 times CO2’s heat-trapping ability
Nitrous oxide – 216 times CO2’s heat-trapping ability
Why the interest in CO2?
• Increasing rapidly in the atmosphere
• Plays a big role high in the atmosphere, where
it is quite dry—i.e., little water vapor.
Greenhouse gases
• Carbon dioxide: released when biomass
(wood) or fossil fuels are burned
• Methane: released when organic waste
decomposes in landfills; by livestock; during
processing of fossil fuels
• Water vapor: evaporation from ocean.
The Carbon Cycle
Some of the Sun’s energy is reflected
back to space
•
Albedo = how much
light an object or
surface reflects
1.
2.
Light ice reflects
Dark land absorbs