30 terms

Ch 11 Atmosphere 2015

Glencoe Earth Science: Geology, the Environment, and the Universe
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Atmosphere
The blanket of gases surrounding the earth. It contains 78% nitrogen, 21% oxygen, and 1% other gases such as carbon dioxide, water vapor, and argon.
Ozone
Chemical in the stratopshere that absorbs harmful ultraviolet radiation from the sun. It is made of 3 atoms of oxygen (O3).
Troposphere
Layer of atmosphere closest to Earth's surface. Layer with the most mass, where weather occurs, and where pollution collects. In the troposphere the temperature decreases with altitude.
Tropopause
The upper limit/boundary of the troposphere; the transition zone between the troposphere and the stratosphere. ("Pause" = "stop", stopping point)
Stratosphere
Layer of the atmosphere that contains the ozone layer. It is located above the tropopause. Temperature in the stratosphere increases with altitude.
Stratopause
The upper limit/boundary of the stratosphere; the transition zone between the stratosphere and the mesosphere. ("Pause" = "stop", stopping point)
Heat
The energy transfer that occurs because of a difference in temperature between two substances. The energy flows from the object with a higher temperature to an object with a lower temperature.
Radiation
The energy transfer through space by visible light, UV radiation, and other forms of eletromagnetic waves (occurs with gases only).
Conduction
The energy transfer that occurs when molecules collide with each other. It occurs only when substances are IN CONTACT with each other.
Convection
The energy transfer by the flow of a heated substance (occurs with liquids and gases). It is caused by uneven heating - one part of the liquid or gas is hotter, is less dense and rises.
Temperature
The measurement of how quickly or slowly molecules move around. Usually measured in degrees Celsius or Kelvin.
Temperature inversion
When temperature increases with altitude in the troposphere, which is the opposite of normal. Inversions can worsen pollution problems
Dew Point
The temperature to which air must be cooled to reach saturation and at which condensation begins. (AKA Condensation Point)
Saturation
The point at which air is holding as much water vapor as it possibly can. AKA 100% relative humidity.
Condensation
Phase change when a cooling gas changes into a liquid, releasing latent heat.
Lifted Condensation Level (LCL)
Altitude where air is cooled to the dew point temperature causing condensation and clouds to form. It is level with the bottom of the clouds.
Humidity
The ACTUAL/absolute measured amount of water vapor present in the air. Usually measured in grams H2O per cubic meter of air.
Relative Humidity
The ratio of the ACTUAL amount of water vapor that air contains compared to the maximum amount it CAN hold at a specific temperature. Expressed as a percent.

Equation:
Relative Humidity = Actual Humidity /Capacity x 100%

Warm air can hold more water vapor than cold air, so with the same amount of absolute/actual humidity, air will have a higher relative humidity.

EXAMPLES: A relative humidity of 50% means the air is holding 50% of water needed for the air to be saturated.
Condensation Nuclei
Small particles in the atmosphere needed for water droplets can condense on and form clouds. Example nuclei: dust, salt, smoke.
Orographic Lifting
Process by which warm moist air is forced to quickly rise over mountains until it cools, reaches saturation, and condensation/clouds occur.
Frontal Wedging
Occurs when 2 air masses collide the warm air is forced over the colder air mass because it is less dense. A line of clouds usually forms where the 2 air masses collide,
Latent Heat
Is heat energy absorbed or released by a substance during a phase change. During evaporation, energy is added and stored in the water vapor. During condensation, the stored energy is released and the atmosphere is warmed, causing air to continue to rise, condense and form clouds.
Cirrus clouds
High altitude clouds that are thin, wispy and stringy with curled tips. Made of ice crystals.
Cumulus clouds
Puffy, lumpy, or fluffy clouds that look like cotton balls or clumps of popcorn.
Stratus clouds
Clouds that are "stretched" flat across the sky like a sheet or blanket.
Cumulonimbus clouds
Tall "thunderhead" storm clouds.
Collision - Coalescence
Process that occurs when cloud droplets collide to form larger droplets that will eventually become too heavy to be held up and will fall to the ground. precipitation.
Precipitation
All solid & liquid forms of water, snow, rain, hail, sleet that fall from clouds.
Evaporation
Phase change that requires and absorbs heat energy as a substance changes from a liquid to a gas.
Water Cycle
The continual movement (cycle) of water between the Earth's surface and the atmosphere through evaporation, condensation, and precipitation.