climate
The average weather that occurs in a given region over a long period of time.
troposphere
A layer of the atmosphere closest to the surface of Earth, extending up to approximately 16 km (10 miles) and containing most of the atmosphere's nitrogen, oxygen, and water vapor.
stratosphere
The layer of the atmosphere above the troposphere, extending roughly 16 to 50 km (10-31 miles) above the surface of Earth.
Ozone
a pale blue gas composed of molecules made up of three oxygen atoms (O3),forms a layer within the stratosphere.
mesosphere
The mesopause, the temperature minimum that marks the top of this level, is the coldest place on Earth and has an average temperature around ?85 �C (?120 �F; 190 K).
thermosphere
Just outside the mesosphere
exosphere
The outermost layer of Earth's atmosphere extends from the exobase upward. It is mainly composed of hydrogen and helium. The particles are so far apart that they can travel hundreds of kilometers without colliding with one another. Since the particles rar
Primary Causes of Uneven Heating of Earth
1. variation in the angle at which the Sun's rays strike Earth
2. variation in the amount of surface area over which the Sun's rays are distributed
3. some areas of Earth reflect more solar energy than others
albedo
The percentage of incoming sunlight reflected from a surface
Air has four properties that determine how it circulates in the atmosphere:
density, water vapor capacity, adiabatic heating or cooling, and latent heat release.
less dense air
rises
denser air
sinks
saturation point
The maximum amount of water vapor in the air at a given temperature
As air rises higher in the atmosphere, the pressure on it...
decreases
adiabatic cooling
The cooling effect of reduced pressure on air as it rises higher in the atmosphere and expands
adiabatic heating
The heating effect of increased pressure on air as it sinks toward the surface of Earth and decreases in volume
latent heat release
The release of energy when water vapor in the atmosphere condenses into liquid water
Hadley cell
A convection current in the atmosphere that cycles between the equator and 30� N and 30� S
intertropical convergence zone (ITCZ)
An area of Earth that receives the most intense sunlight; where the ascending branches of the two Hadley cells converge.
polar cell
A convection cell in the atmosphere, formed by air that rises at 60� N and 60� S and sinks at the poles, 90� N and 90� S
Coriolis effect
The deflection of an object's path due to the rotation of Earth
thermohaline circulation
An oceanic circulation pattern that drives the mixing of surface water and deep water
El Ni�o-Southern Oscillation (ENSO)
The periodic changes in winds and ocean currents, causing cooler and wetter conditions in the southeastern United States and unusually dry weather in southern Africa and Southeast Asia.
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.
biome
A geographic region categorized by a particular combination of average annual temperature, annual precipitation, and distinctive plant growth forms on land, and a particular combination of salinity, depth, and water flow in water.
tundra
A cold and treeless biome with low-growing vegetation
permafrost
An impermeable, permanently frozen layer of soil.
boreal forest
A forest made up primarily of coniferous evergreen trees that can tolerate cold winters and short growing seasons.
temperate rainforest
A coastal biome typified by moderate temperatures and high precipitation
temperate seasonal forest
A biome with warmer summers and colder winters than temperate rainforests and dominated by deciduous trees.
woodland/shrubland
A biome characterized by hot, dry summers and mild, rainy winters.
temperate grassland/cold desert
A biome characterized by cold, harsh winters, and hot, dry summers.
tropical rainforest
A warm and wet biome found between 20? N and 20� S of the equator, with little seasonal temperature variation and high precipitation.
tropical seasonal forest/savanna
A biome marked by warm temperatures and distinct wet and dry seasons
subtropical desert
A biome prevailing at approximately 30? N and 30� S, with hot temperatures, extremely dry conditions, and sparse vegetation.
Streams and rivers
characterized by flowing fresh water that may originate from underground springs or as runoff from rain or melting snow
base of the food web for streams/rivers
inputs of organic matter from terrestrial biomes
Lakes and Ponds
contain standing water, at least some of which is too deep to support emergent vegetation
freshwater wetland
An aquatic biome that is submerged or saturated by water for at least part of each year, but shallow enough to support emergent vegetation.
Swamps
wetlands that contain emergent trees
Marshes
wetlands that contain primarily nonwoody vegetation, including cattails and sedges
Bogs
very acidic wetlands that typically contain sphagnum moss and spruce trees
salt marsh
A marsh containing nonwoody emergent vegetation, found along the coast in temperate climates
mangrove swamp
A swamp that occurs along tropical and subtropical coasts, and contains salt-tolerant trees with roots submerged in water
intertidal zone
The narrow band of coastline between the levels of high tide and low tide
coral reef
The most diverse marine biome on Earth, found in warm, shallow waters beyond the shoreline
photic zone
The upper layer of water in the ocean that receives enough sunlight for photosynthesis
aphotic zone
The layer of ocean water that lacks sufficient sunlight for photosynthesis
chemosynthesis
A process used by some bacteria in the ocean to generate energy with methane and hydrogen sulfide