The Atmosphere and Climate

Atmosphere

Atmosphere The mixture of gases that surrounds Earth Nitrogen, oxygen, carbon dioxide, and other gases are all parts of this mixture These gases are constantly added and removed

Composition of the Atmosphere 78% Nitrogen 21% Oxygen

Not just gases The atmosphere also contains atmospheric dust (many types of tiny, solid particles) in addition to gases. Atmospheric dust can include: Soil Salt Ash Pollen Bacteria and viruses Aerosols – tiny liquid droplets

Layers of the Atmosphere Four layers: Troposphere Stratosphere Mesosphere Thermosphere

Troposphere The atmospheric layer nearest the surface of the Earth It extends to 18 km above Earth’s surface

Stratosphere The layer above the troposphere Where the ozone layer is located

Mesosphere The layer above the stratosphere Extends to an altitude of about 80 km

Thermosphere Layer of the atmosphere furthest from Earth’s surface

Temperature in the Atmosphere

Energy and Heating Three mechanisms transfer energy from the sun: Radiation Convection Conduction Radiation - the transfer of energy across space and in the atmosphere Convection - the transfer of heat by air currents. Hot air rises and cold air sinks. Conduction - the flow of heat from a warmer object to a colder object when the objects are placed in direct physical contact

Heating Earth Our planet only receives about two-billionths of the sun’s energy About half the energy that reaches the atmosphere will pass though to Earth’s surface

Weather and Climate

The Earth Has Many Different Climates (1) Weather Climate Air circulation in lower atmosphere due to:

The Earth Has Many Different Climates (2) Currents Prevailing winds Earth’s rotation Redistribution of heat from the sun

Natural Capital: Generalized Map of the Earth’s Current Climate Zones

Global Air Circulation

Coriolis Effect

Energy Transfer by Convection in the Atmosphere

Connected Deep and Shallow Ocean Currents

Thermohaline Circulation

Global Air Circulation, Ocean Currents, and Biomes

Greenhouse Gases Warm the Lower Atmosphere CO2 CH4 N2O Greenhouse effect Human-enhanced global warming

Flow of Energy to and from the Earth

The Earth’s Surface Features Affect Local Climates Heat absorption by land and water Effect of Mountains Rain shadow effect Cities Microclimates

Rain Shadow Effect