Unit 3: Atmosphere, Clouds, Humidity (Intro)

Alto

prefix meaning cloud is found higher in the sky than usual

Capacity

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

Cirrus

high-altitude clouds that are thin, feathery tufts of ice crystals.

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.

Convergence

as air is drawn together at the surface, like when there is a surface low pressure, it causes an upward movement of air.

Cumulonimbus

a type of cumulus cloud that has vertical development, gray color, and associated with downpours, thunderstorms, tornadoes, hail and cold fronts

Cumulus

low altitude thick, puffy, white clouds with flat bases, formed by vertically rising air currents often localized convective lifting or convergence

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

Fog

a cloud in contact with the ground

Frost

feathery crystals of ice formed on surfaces when water vapor in the air deposits at a temperature below freezing

Halo

a circle of light around the sun or moon in a cirrostratus cloud

Latent Heat

heat absorbed or radiated during a change of phase

Mare's Tail

type of cirrus cloud with a hook shape that can indicate rain within 24 hours if caused by a warm front

Mountain Wave Cloud

stationary lenticular clouds situated over and downwind of a prominent mountain range

Nimbo

prefix-suffix to indicate that a cloud is rain-bearing

Orographic Lifting

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

precipitation

Any form of water that falls from clouds and reaches Earth's surface.

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. When air is saturated it is also 100% RH and the dewpoint temperature has been reached so there will be condensation.

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.

Stratus

clouds that form in low, horizontal layers, covering all or most of sky

Transpiration

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

Water Vapor

water in its gaseous form

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. In the stratosphere it protects us from dangerous ultraviolet radiation. In troposphere it is considered a pollutant as it is a main ingredient in photochemical smog and damaging to plants and people.

Stratosphere

The layer of Earth's atmosphere that extends from the troposhere to the mesosphere; concentration of ozone in this layer causes the temperature to rise as you go up.

Thermosphere

The layer of Earth's atmosphere above the mesosphere, characterized by increasing temperatures with altitude.

Troposphere

The lower layer of the atmosphere where we live. The temperature decreases with altitude

Meteorology

The scientific study of the atmosphere and atmospheric phenomena; the study of the weather and climate

Weather

the state of the atmosphere at any given time, varies considerably and is described and measured by the "elements of weather" such as cloud cover and type, wind direction and speed, humidity, temperature etc.

Climate

a description of aggregate weather conditions; the sum of all statistical weather information that helps describe the weather of a region, the "expected" norm against which this year's/today's weather can be compared. Usually graphically described in terms of monthly temperature and precipitation.

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.

Stratopause

The boundary between the stratosphere and the mesosphere

Mesopause

The boundary between the mesosphere and the thermosphere

atmosphere

the envelope of gases surrounding the earth

leeward side

Protected side; the direction opposite from which the wind is blowing.

windward side

the side or direction from which the wind is blowing.

rain shadow

a region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean causing precipitation on the windward side

adiabatic cooling

the cooling effect of reduced pressure on air as it rises higher in the atmosphere and expands