Unit 2: Atmosphere, Clouds, Humidity-Intro (Rugg 25-26)

Capacity

the maximum amount of water that can be present in the air at a certain temperature; increases with increasing temperature.

Cloud

a collection of small water droplets or ice crystals suspended in the air

Condensation

the change from water vapor to liquid water

Condensation Nuclei

microscopic particles on which water vapor condenses to form cloud/fog droplets.

Deposition

phase change from gas to solid

Dew

tiny drops of water that form on cool surfaces when water vapor condenses

Dew Point

the temperature at which condensation occurs because the air is saturated

Evaporation

the change from liquid water to water vapor

Latent Heat

heat absorbed or radiated during a change of phase

Orographic Lifting

mountains acting as barriers to the flow of air, forcing the air to rise.

Relative Humidity

a comparison of the actual amount of water vapor in the air with the maximum amount of water vapor that can be present in the air. (Specific Humidity/Capacity)

Saturation

the condition in which the air is holding as much water vapor as possible at a given temperature and pressure.

Specific Humidity

the amount of water vapor in the air at a given time and place; expressed as the number of grams of water vapor per kilogram of air.

Transpiration

the emission of water vapor into the atmosphere from the leaves of plants

Mesosphere

The layer of the Earth's atmosphere that extends from the stratosphere to the thermosphere, characterized by decreasing temperatures.

Ozone

a form of oxygen that has three oxygen atoms in each molecule instead of two.

Stratosphere

The second layer of Earth's atmosphere; concentration of ozone in this layer causes the temperature to rise as you go up.

Thermosphere

The highest layer of Earth's atmosphere, characterized by increasing temperatures with altitude in which you find auroras occuring, and gas molecules stratified by type.

Troposphere

The lowest layer of the atmosphere. The temperature decreases with altitude and 80% of the mass of the atmosphere is in this air-molecule dense layer as is almost all of the water vapor..

Meteorology

is the branch of science concerned with the phenomena of the atmosphere, specifically with respect to weather and climate

Weather

The state of the atmosphere at a given place in time with respect to "weather variables" such as cloud cover and type, wind direction and speed, humidity, temperature etc.

Climate

statistically averaged weather conditions over a 30+ year period that helps describe the "typical" weather of a region.

Outgassing

The process of gases contained within the Earth being put into the atmosphere by volcanic eruptions.

Tropopause

The boundary between the troposphere and the stratosphere in which temperature does not rise or fall with increasing altitude.

atmosphere

The gaseous envelope of air surrounding the Earth

adiabatic cooling

cooling due to expansion as when air rises or is lifted and expands due reduced pressure on it

variable components

componants of the atmosphere that can change from place to place or day to day such as water vapor, ozone, pollution, aerosols.

aerosols

Tiny solid and liquid particles suspended in the atmosphere such as sea salt, dust, ash, smoke, pollen

Chloroflourocarbons

Widely used, man-made chemical containing chlorine that destroys stratospheric ozone and lasts a long time in the stratosphere

Montreal Protocol (1987)

An agreement on protection of the ozone layer in which states pledged to reduce and then eliminate use of chlorofluorocarbons (CFCs). It is the most successful environmental treaty to date.

ozone hole

the area of lowered ozone concentration over Antarctica

Sublimation

the process in which a solid changes directly into a gas

Ionisphere

the part of the earth's atmosphere that contains a high concentration of ions and free electrons and is able to reflect radio waves.

alto

prefix added to clouds forming at the middle altitude of the troposphere

cirro

prefix added to clouds forming at the top altitude of the troposphere

cumulus

the family of clouds that has a heaped, puffy, often flat bottomed shape.

stratus

The family of clouds that form in flat layers and often cover much of the sky.

cirrus

The family of clouds that are wispy, feathery clouds made of ice crystals that only form at high levels.

nimbo/nimbus

Prefix/suffix added to a cloud to indicate it is one that brings rain.