troposphere: layer of the atmosphere in which weather occurs and we have direct contact with
stratosphere: layer of the atmosphere above the troposphere containing naturally occurring ozone
thermosphere: layer of the atmosphere above the mesosphere
mesosphere: layer of atmosphere above the stratosphere
albedo: a measure of the amount of solar radiation reflected by a surface of the earth
saturation point: the maximum amount of water vapor that air can hold per given temperature
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 in sinks toward the earth and decreases in volume
latent heat release: the release of energy when water vapor in the atmosphere condenses into liquid water
Hadley cells: atmospheric convection currents that cycle between the equator and 30º north and south
Polar cells: atmospheric convection cells that form with air rising at 60º north and south and sinking at the poles (90º north and south)
Intertropical Convergence Zone: area of the earth that receives the most direct solar radiation, fluctuates around the equator
Coriolis effect: the deflection of an object’s path due to the rotation of the earth
gyre: large-scale pattern of ocean surface currents; clockwise in the northern hemisphere, counterclockwise in the southern
upwelling: the upward movement of ocean water toward the surface as a result of diverging currents
thermohaline circulation: deep ocean currents that start in the poles with the sinking of cold and salty dense water
El Nino-Southern Oscillation: periodic changes in trade winds and ocean currents in the Pacific Ocean that affect
weather patterns globally
rain shadow: region with dry conditions found on the leeward side of coastal mountain ranges
magma: molten rock
asthenosphere: the layer of the mantle in which convection current of semi-molten rock move the lithospheric plates above
lithosphere: the uppermost layer of the mantle and the crust
oceanic crust: crust that is made mostly of basaltic rock and is very dense
continental crust: crust that is made mostly of granitic rock and is less dense than the other type of crust
hot spots: places where molten material rises from the asthenosphere and reaches the lithosphere
seafloor spreading: the formation of new oceanic crust as a result of divergent lithospheric plates
volcano: a vent in the earth’s surface that emits ash, gases, or molten lava
earthquake: the sudden movement of earth’s crust caused by a release of energy along a fault line
mineral: a solid chemical substance with a uniform and often crystal structure
intrusive igneous rock: rock that forms when magma rises up from the asthenosphere and cools underground in the lithosphere
extrusive igneous rock: rock that forms when magma cools above the earth’s surface
sedimentary rock: rock that forms when muds, sands, or gravels are compressed by overlying sediments
metamorphic rock: rock that forms when other rocks are subjected to high temperature and pressure
physical weathering: the mechanical breakdown of rocks and minerals
chemical weathering: the chemical breakdown of rocks and minerals through reactions or dissolving
erosion: the physical removal of rock fragments or soil from a landscape or ecosystem
parent material: rock underlying soil from which the inorganic components of soil originate
humus: partially decomposed organic material
O horizon: when present, the top layer of soil composed of leaf litter and other recognizable organic components
topsoil: the A horizon in a soil profile, composed of humus and inorganic material
E horizon: the zone of leaching that forms under either the O or A horizon in acidic soils
subsoil: the B horizon in a soil profile, composed mainly of inorganic mineral materials from the C horizon and
nutrients that have leached from the O and A horizons
soil texture: the ratio of particles of clay, silt, and sand in soil
soil degradation: the loss of some or all of a soil’s ability to support plant growth
loam: a mixture of 20% clay, 40% silt, and 40% sand
base saturation: the proportion of bases to acids in soil
cation exchange capacity: the ability of a soil to absorb and release cations
windbreak/shelterbelt: border of trees around agricultural fields to limit erosion of topsoil by wind
contour planting: planting with the contours of a hilly landscape
terracing: cutting flat ledges into hilly landscapes for farming
agroforestry: planting crop rows with alternating rows of trees to decrease erosion
crop rotation: the alternation of crops with groundcover plants to decrease off-season erosion