Heating of the AtmosphereChapter 15 Section 2

Mrs. MannelEarth Science

Energy in the Atmosphere• The Earth receives energy from the sun

by radiation• Radiation is the transfer of energy as

electromagnetic waves• The Earth only receives two-billionths

of this energy• When energy is absorbed by a surface,

it heats that surface

Conduction

• Conduction is the transfer of thermal energy from one material to another by direct contact

• Thermal energy is transferred to a sidewalk, then to your foot

• Thermal energy always moves from warm to cold areas

Convection

• Convection is the transfer of thermal energy by the circulation or movement of a liquid or gas

• Cool air is more dense and sinks, as the cool air sinks, it pushes the warm air up. The cool air is eventually heated by the ground and rises creating a convection current

The Greenhouse Effect• The gases in the Earth’s atmosphere

trap thermal energy and act like a layer of glass

• The gases allow solar energy to pass through which warms the Earth

• Too many of these gases are being trapped which is causing the global temperatures to rise

Global Warming

• Not all gases cause warming, only the greenhouse gases

• Carbon Dioxide and Methane gas are increasing global temps caused by the burning of fossil fuels

• http://www.youtube.com/watch?v=VVXxznHgH8c

The Radiation Balance

• For the Earth to remain livable, the amount of energy received from the sun and the amount of energy returned to space must be equal

• Some scientists argue that Earth had warmer temps abd that this is a natural process

• Nevertheless, countries are uniting to stop global warming