Geo mid-term review Ch. 4

Electromagnetic Spectrum waves from short to long

1. Cosmic Rays, 2. Gama rays, 3. X-Rays, 4. Ultra violet, 5. Visible light, 6. infrared, 7. microwaves, 8. TV/FM radio, 9. AM radio,10. Long Radio waves.

Solar radiation is almost completely in these forms

1. Visible light, 2. ultraviolet radiation and 3. short infrared radiation

Adiabatic cooling

Adiabatic cooling is cooling by expansion. Adiabatic means with out the gain or loss of heat. As air rises there is more room and less pressure. The molecules move away from each other which takes energy and they also do not collide with each other Thus the air cools adiabatically.

Adiabatic warming

Adiabatic warming happens when air descends and compresses. The air becomes warmer as it comes under increasing pressure. Molecules draw closer together and collide which results in an increase in temperature even though no heat is added.

Role of clouds in temperature influence

Clouds absorb long wavelength radiation from Earth's surface and short wavelength radiation from the sun. Their influence on temperature varies depending on the time of day and what type of clouds. In the daytime if there is no cloud cover the temperature generally increases and with a cloud cover it decreases while at night the effect is the opposite.

Latent Heat v. Specific Heat

Energy stored or released when a substance changes state. Ex. evaporation is a cooling process because latent heat is stored and condensation is a warming process because latent heat is released. Specific heat is the amount of energy required to raise the temperature of 1 gram of a substance by 1 degree C For example, Water has a higher specific heat than land.

Convection

Heat is transferred from one point to another by the predominately vertical circulation of a fluid such as air or water. Convection involves movement of heated molecules from one place to another.

difference between conduction and convection

In convection molecules move around. In conduction molecules move back and forth and collide. In convection molecules physically move away from the heat source in conduction they collide with it.

**Insolation

Insolation is incoming solar radiation which is received at the top of the atmosphere and is believed to be constant when averaged over a year. This constant amount of incoming energy is referred to as the solar constant. There is a balance between the total amount of insolation received by Earth and the amount returned to space. Most of the insolation that enters the atmosphere does not heat it directly. About 45 units of insolation pass on through the atmosphere to Earth's surface leaving only 24 units to heat the atmosphere directly. 3 heats the ozone layer and 21 heating the rest of the atmosphere.

Ozone layer

Layer of gaseous ozone (O3) in the stratosphere that protects life on earth by filtering out most harmful ultraviolet radiation from the sun. The Ozone layer is not entirely made of ozone, it is just an area where the concentration of ozone relative to other gasses is at its greatest concentration

Terrestrial Radiation

Radiation emitted by Earth is entirely in the thermal infrared portion of Electromagnetic Spectrum and is referred to as longwave radiation. Due to a natural greenhouse effect large amounts of terrestrial energy is reradiated back to Earth. In effect the surface heats the lower atmosphere and the lower atmosphere reheats the surface.

Specific heat - Land v. Water

Specific heat is the amount of energy required to raise the temperature of 1 gram of a substance by 1 degree. Water has a higher specific heat than land. The specific heat of water is about 5 times that of land. Water can absorb much more solar energy without it's temperature increasing.

Temperature v. heat

Temperature is a description of the average kinetic energy of the molecules in a substance. I.e. the more vigorous the jiggling of the molecules the more kinetic energy and the higher the temperature. Heat refers to energy that transfers from one object to another because of a difference in temperature. Heat is simply energy that is transferred from an object with a higher temperature to an object with a lower temperature.

albedo

The fraction of total solar radiation that is reflected back, unchanged into space.

Conduction

The movement of heat energy from one molecule to another without changes in their relative positions. When two molecules of unequal temperature are in contact with one another, heat energy tranfers from the hotter to the cooler until they attain the same temperature. The Earth is a good absorber of heat the air is a poor conductor and moist air is slightly more efficient conductor than dry air.

Greenhouse effect on climate change

The ongoing natural greenhouse effect of the earth makes life as we know it possible i.e Greenhouse gasses readily transmit incoming shortwave solar radiation but do not easily transmit outgoing long wave terrestrial radiation that radiation is redirected to the Earth warming it's surface. However, over the last 100 years there has been an increase in greenhouse gasses, most notably carbon dioxide which has caused the earth to get warmer. This slight increase of temperature can cause major climate changes in the long run.

Infrared Radiation

Wavelengths of radiation just longer than the human eye can sense. Infrared radiation ranges from short or near infrared wavelengths to longer wavelengths called thermal infrared.

Ultraviolet Radiation

Wavelengths of radiation just shorter than the human eye can sense. The Sun is a prominent natural resource of UV rays.

Visible light

Wavelengths of radiation to which human eye is sensitive. A fairly narrow band of the electromagnetic spectrum. Visible light ranges from the shortest wavelength the human eye can sense i.e. violet through the progressively longer wavelengths of blue, green, yellow, orange and red. ROYGBIV is long to short wavelengths

absorption

When electromagnetic waves strike an object and are assimilated it is called absorption. An increase in temperature is a typical response to absorption of electromagnetic radiation. Minerals, rock, soil are excellent absorbers; snow and Ice are poor absorbers. Dark surfaces are more efficient absorbers than light surfaces

Temperature inversion

When the temperature in the troposphere increases, rather than decreases, with increasing altitude. An inversion inhibits vertical air movement and therefore can influence climate by greatly diminishing possibility of precipitation. Increase air pollution because they create stagnant air.Relatively common in troposphere but usual brief and restricted in depth.

The boundary on the Electromagnetic Spectrum separating short from long wavelengths

a wavelength of 4 micrometers

Water vapor v carbon dioxide

both efficient absorbers of certain wavelengths of radiation. Carbon dioxide is distributed uniformly in the lower layers of Earth's atmosphere, water vapor is not.

Scattered light waves that continue through the atmosphere strike the surface as

diffused radiation

scattering

is a type of reflection where gas molecules and particulate matter in the air can deflect light waves and redirect them. This involved change in direction of the light wave but no change in wavelength. Some waves are backscattered into space and lost to Earth. Many continue through the atmosphere in altered but random directions.

Thermal Infrared

long wave radiation emitted by Earth

Electromagnetic Spectrum

the entire frequency range of electromagnetic waves, arrangement of electromagnetic radiation--including radio waves, visible light from the Sun, gamma rays, X rays, ultraviolet waves, infrared waves, and microwaves--according to their wavelengths. Electromagnetic radiation varies enormously in wavelength from short wavelengths of gamma rays and X-rays to long wavelengths of television and radio waves.