Chapter 2: The Physical Environment

Acidity

A measure of the ability of a solution to behave as an acid, a compound that releases protons (H+) to the water in which it is dissolved.

is dissolved. Is

Albedo

The amount of solar radiation reflected by a surface, usually expressed as a percentage of the incoming solar radiation.

Alkalinity

A measure of the ability of a solution to behave as a base, a compound that takes up protons (H+) or releases hydroxide ions (OH-).

ions (OH_)

Atmospheric Pressure

The pressure exerted on a surface due to the mass of the atmosphere above it.

Climate

The long-term description of weather, based on averages and variation measured over decades.

Conduction

The transfer of sensible heat through the exchange of kinetic energy between molecules due to a temperature gradient.

Continental Climate

The climate typical of terrestrial areas in the middle of large continental land masses at high latitudes, characterized by high variation in seasonal temperatures.

high variation in seasonal

Convection

The transfer of sensible heat through the exchange of air and water molecules as they move from one area to another.

Coriolis Effect

The apparent deflection of air or water currents when viewed from a rotating reference point such as Earth’s surface.

Downwelling

The sinking of deep ocean water from the surface.

En Nino Southern Oscillation (ESNO)

An oscillation of pressure cells and sea surface temperatures in the equatorial Pacific Ocean that causes widespread climatic variation and changes in upwelling currents.

Epilimnion

The warm surface layer of water in a lake, lying above the thermocline, that forms during the summer in some lakes of temperate and polar regions.

Evapotranspiration

The sum of water loss through evaporation and transpiration.

Ferrell Cell

A large-scale, three-dimensional pattern of atmospheric circulation in each hemisphere, located at mid-latitudes between the Hadley and polar cells.

Greenhouse Effect

The warming of Earth by gases in the atmosphere that absorb and reradiate infrared energy emitted by Earth’s surface.

Greenhouse Gases

Atmospheric gases that absorb and reradiate the infrared radiation emitted by Earth’s surface, including water Vapor (H2O), Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).

Hadley cell

A large-scale, three-dimensional pattern of atmospheric circulation in each hemisphere in which air is uplifted at the equator and subsides at about 30 degrees N and S.

Heat Capacity

The amount of energy required to raise the temperature of a substance.

Hypolimnion

The densest, coldest water layer in a lake, lying below the thermocline.

Hypoxic

Of or relating to a condition of oxygen depletion, usually below a level that can sustain more animals.

Intertropical Convergence Zone (ITCZ)

The zone of maximum solar radiation, atmospheric uplift, and precipitation within the tropical zone.

Lapse rate

The rate at which atmospheric temperature deceases with increasing distance from the ground.

Latent heat flux

Heat transfer associated with the phase change of water, such as evaporation, sublimation, or condensation.

Maritime Climate

The climate typical of costal terrestrial regions that are influenced by an adjacent ocean, characterized by low daily and seasonal variation in temperature.

North Atlantic Oscillation

An oscillation in atmospheric pressures and ocean currents in the North Atlantic Ocean that affects climatic variation in Europe, in northern Asia, and on the east coast of North America.

Pacific Decadal Oscillation (PDO)

A long-term oscillation in sea surface temperatures and atmospheric pressures in the North Pacific Ocean that has widespread climatic effects.

Polar Cells

A large-scale, three-dimensional pattern of atmospheric circulation in which air subsides at the poles, moves toward the equator when it reaches Earth’s surface, and is replaced by air moving through the upper atmosphere from lower latitudes

Polar zones

The major climatic zone above 60N and S.

Rain Shadow Effect

The effect a mountain range has regional climate by forcing moving air upward, causing it to cool and release precipitation on the windward slopes, resulting in lower levels of precipitation and soil moisture on the leeward slope.

Salinity

The concentration of dissolved salts in water.

Salinization

A process by which high rates of evapotranspiration in arid regions results in a progressive buildup of salts at the soil Surface.

Sensible Heat flux

The transfer of heat through the exchange of energy by conduction or convection.

Stratification

The layering of water in oceans and lakes due to differences in water temperature and density with depth.

Subsidence

A sinking (downward) movement of air in the atmosphere, usually over a broad area, leading to the development of a high-pressure cell.

Temperate Zones

The major climatic zone between 30 and 60N and S.

Thermocline

The zone of rapid temperature change in a lake beneath the epilimnion and above the hypolimnion.

Tropical Zone or Tropics

The major climatic zone between 25 N and S, encompassing the equator; also called the tropics.

Turnover

(1) The mixing of the entire water column in a stratified lake when all the layers of water reach the same temperature and density.

(2) The change in species diversity and composition from one community type to another across the landscape

The change in species diversity and composition, or turnover of species, from one community type to another across the landscape.

Uplift

The rising of warm, less dense air in the atmosphere due to heating of Earth’s surface.

Upwelling

The rising of deep ocean waters to the surface.

Weather

The temperature, humidity, precipitation, wind, and cloud cover at a particular time and place.

Weather