Factors that Influence Climate 3 main factors: 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: Latitude 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 Latitude Altitude 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 Latitude Altitude 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 Latitude Altitude Oceanic Circulation Other important factors Atmospheric Circulation Solar activity Radiation Animation Solar maximum 11 year cycle

Factors that Influence Climate 3 main factors Latitude Altitude 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 Latitude Altitude 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 Light ice reflects Dark land absorbs