ClimateLong time, Large Area

Weathershort term, small area

Heat and Temperature• Temperature

-A measure of kinetic energy. a measure of the speed of molecules • Heat

-The energy transferred from one object to another.

*Heat always moves from higher temperature to a lower temperature. Heat will try to reach an equilibrium.

Heat Transfer Mechanisms

• Conduction• Convection• Radiation

Energy Transfer as Heat

• Conduction - The transfer of heat through matter by touch or molecular activity.

• Convection - The transfer of heat by mass movement.

• Radiation – Travels in all directions from it’s source.

Conduction, convection and radiation are shown to the right by heating up a pot of water.

http://www.aos.wisc.edu/~aalopez/aos101/wk5.html

Radiation

• Waves of energy that can travel through empty space. It does not need to; make contact, to move through molecules of a fluid (air or liquid)

• The Sun’s energy is transferred through Radiation

Electromagnetic Spectrum(a list of the forms of energy from the Sun)

• Electromagnetic spectrum is classified according to wavelength.

• Types of electromagnetic spectrum are;– Gamma Rays– X-Rays– Ultraviolet Rays– Visible light– Infrared– Microwaves– Television/FM Radio– Shortwave Radio– AM Radio– Long Radio Waves

Basic Laws Governing Radiation• All objects, at any temperature emit radiant

heat.• Hotter objects radiate more total energy per

unit area than colder objects do.• The hottest radiating bodies produce the

shortest wavelengths of maximum radiation.• Objects that are good absorbers of radiation

are good emitters.

http://www.aos.wisc.edu/~aalopez/aos101/wk5.html

Radiation >>>

Solar Radiation• Things that can happen when radiation strikes

on an object:– Some energy is absorbed– Substances such as water and air are transparent

to waves– Some radiation may bounce off the object without

being absorbed

Reflection and Scattering

• Reflection occurs when light bounces off an object.

• Scattering produces a larger number of weaker rays that travel.

http://www.google.com/imgres?q=Reflection+and+Scattering&um=1&hl=en&client=firefox-a&sa=N&rls=org.mozilla:enUS:official&biw=1429&bih=999&tbm=isch&tbnid=CDz6XZAQ916ULM:&imgrefurl=http://www.usra.ca/basic_p&docid=PxrGH6Wmf9AicM&w=420&h=267&ei=AqNyTp6jLZGGsALjrZ22CQ&zoom=1&iact=hc&vpx=182&vpy=162&dur=2987&hovh=179&hovw=282&tx=174&ty=64&page=1&tbnh=130&tbnw=205&start=0&ndsp=32&ved=1t:429,r:0,s:0

Albedo

Approximately one half of the solar energy that strikes our atmosphere is absorbed, and some is also radiated back skyward. This is called albedo, the fraction of the total radiation that is reflected by a surface. This solar energy is radiated back from different surfaces on the Earth and consists mostly of longer wavelengths. This is a lower temperature.

http://www.esr.org/outreach/glossary/albedo.html

• Crops, green• Black asphalt• Fresh snow

• Ploughed field• Grey concrete• Water

Where does the atmosphere acquires most of its energy?

What two gases in the lower atmosphere absorb the most radiation?

Heat energy radiating UP from the Earth’s surface

Carbon dioxide (CO2) and water vapor (H2O)

Greenhouse Effect

• A process where thermal radiation from a planetary surface is absorbed by atmospheric green house gasses.

http://www.myclimatechange.net/default.aspx?Page=Article&SubjectId=14&cat=1&sub=1