factors that influence climate 3 main factors: 1.latitude distance from the equator angle of suns...
TRANSCRIPT
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 A
nimation
Factors that Influence Climate
3 main factors:1. Latitude2. 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 factors1. Latitude2. Altitude3. 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 factors1. Latitude2. Altitude3. Oceanic CirculationOther 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 factors1. Latitude2. Altitude3. Oceanic CirculationOther important factors• Atmospheric Circulation• Solar activity
Radiation Animation
• Solar maximum– 11 year cycle
Factors that Influence Climate
3 main factors1. Latitude2. Altitude3. Oceanic CirculationOther 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
Factors that Influence Climate
3 main factors1. Latitude2. Altitude3. Oceanic CirculationOther important factors• Atmospheric Circulation• Solar activity• Volcanic activity• Topography
• Shape of the land• Rain shadow
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 waysfor 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
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.
Some of the Sun’s energy is reflected back to space
• Albedo = how much light an object or surface reflects
1. Light ice reflects2. Dark land absorbs