The Greenhouse Effect- Atomic levelBy Kaelin O’Hare

Albedo Albedo= the fraction of solar energy reflected from

the Earth into space, or a measure of the reflectivity of the Earth’s surface

-Ice and snow have a high albedo -Water has a low value of albedo

Clouds affect the Earth’s albedo too…- the more water in a cloud, the greater

albedo it has

Annual global mean albedo on Earth= 30%

Greenhouse Effect The Sun’s radiation encounters the Earth in

short wavelengths of visible light Some of the Sun’s radiation is reflected by

clouds and atmosphere, but much is absorbed by the Earth

This absorbed heat is radiated outwards in longer infrared wavelengths and absorbed by greenhouse gases in the atmosphere

Thus the Earth is heated and kept warm enough for life

Greenhouse Gases Main gases: Methane(CH4), Nitrous oxide(N2O), Carbon

Dioxide(CO2), and Water(H2O) Sources:-Methane= wetlands, landfills-Nitrous Oxide= lakes, tropical rainforests, agricultural soil management-Carbon Dioxide= lakes, fossil fuel emissions-Water= water sources, emissions from burning & processing fossil fuel GHGs react to infrared radiation through the process of

resonance-GHGs absorb infrared photons of different wavelengths, which cause their molecules to vibrate and create heat

Black-body Radiation Black body: an object that has no

albedo, and so absorbs all the radiation falling on it

Black-body Radiation: at a particular temperature, the black-body can emit the maximum amount of energy possible for that temperature

-this makes it the perfect emitter

The Sun’s RadiationSolar constant: 1350 W/

The intensity of the Sun’s radiation incident on Earth can be calculated using the equation

= I= the rate at which the Earth absorbs the Sun’s energye= emissivity of EarthA= area cos the angle of incidence I= intensity of the Sun hitting the Earth

Find the intensity of the Sun’s radiation upon California over a day if the angle of incidence of the Sun’s rays upon the Earth is 30

e= 0.70 A= 424,000,000 m² = 6.95 x W

Answer: 271 W/

Works Citedhttp://www.esr.org/outreach/glossary/albedo.htmlhttp://www.atmosphere.mpg.de/enid/25w.htmlhttp://environment.nationalgeographic.com/environment/global-warming/gw-overview-interactive/http://www.lakescientist.com/learn-about-lakes/lakes-climate-change/lakes-and-greenhouse-gases.htmlhttp://www.windows2universe.org/earth/climate/greenhouse_effect_gases.htmlhttp://zebu.uoregon.edu/disted/ph162/l4.html