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Glossary albedo reflectivity of Earth's surface. anthropogenic made by humans. atmosphere the area in which all air exists; this sphere contains all of the gases that surround the earth. biogeochemistry scientific study of the interactions among the biological, geological, and chemical systems of Earth, including the cycling of matter and energy through them; biogeochemical (adverb). biome major division of the ecological communities on Earth characterized by the plant and animal life of that region. biosphere the area in which all living things exist; this sphere includes all of the microorganisms, plants, and animals of Earth, even humans. carbon sink a place where carbon accumulates and is stored. For example, plants are carbon sinks; they accumulate carbon dioxide during the process of photosynthesis and store it in their tissues as carbohydrates and other organic compounds. carbon source a place where carbon is produced or released. For example, plants release carbon in the form of carbon dioxide when their tissues are broken down during combustion. chlorofluorocarbon (CFC) anthropogenic aerosol compound containing chlorine, fluorine, and carbon that is used in propellants, refrigerants, and solvents; freon. climate long-term pattern of weather that characterizes a region. climate model mathematical model containing equations that describe climatic interactions. climatologist scientist who studies climate. combustion the more rapid process of oxidation that occurs when organic matter ignites and burns, producing light and heat; it is the same chemical reaction that occurs during decomposition and respiration, 6 O2 + C6H12O6 ------> 6 H2O + 6 CO2. denitrification reduction of inorganic nitrate (NO3) and nitrite (NO2) to nitrogen gas (N2) and nitrous oxide (N2O) by Microorganisms. decompose to rot or decay; it is the same chemical reaction that occurs during combustion and respiration, 6 O2 + C6H12O6 ----> 6 H2O + 6 CO2. dormant a state in which normal activity is suspended, as in during hibernation. eccentricity shape of Earth's orbit; it varies from being elliptical to almost circular. ecosystem biotic (living) community and abiotic (non-living) environment that function together. evaporation the movement of gaseous water (water vapor) from the Earth's surface to the atmosphere; evaporate (verb). emission substance that is released or discharged, usually into the air; emit (verb). fauna all of the animals that live in an area. flora all of the plants that live in an area. fossil fuels deposits of organic matter that have been altered over geologic time (since the Earth's formation) and can be burned for energy; for example, coal, crude oil, and natural gas. germination the sprouting of a seed or spore; germinate (verb). geologic time all time since the Earth was formed and continuing to the present. gigatons (GT) one billion (1,000,000,000) tons or two trillion (2,000,000,000,000) pounds. global warming net increase in Earth's average temperature. greenhouse effect a warming process that balances Earth's cooling processes and helps maintain an average global temperature of approximately 60 degrees Fahrenheit. During this process, sunlight enters Earths atmosphere as short wave radiation. The radiation is absorbed by Earth's surface. The planet becomes heated and emits long wave radiation toward the atmosphere. In the atmosphere, some of the long wave radiation is absorbed by certain gases called greenhouse gases. Each molecule of greenhouse gas becomes energized and emits heat energy in all directions. By radiating heat energy toward Earth , greenhouse gases increase Earth's temperature. Note that the warming mechanism for the "greenhouse effect" is NOT exactly the same as the warming mechanism of greenhouse walls. While greenhouse gases absorb long wave radiation then emit heat energy it in all directions, greenhouse walls physically trap heat inside of greenhouses and prevent it from escaping to the atmosphere. greenhouse gases certain gases in the Earth's atmosphere that absorb some of the outgoing long wave radiation, or heat energy (see greenhouse effect). These gases include carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). harvest to gather mature crops (verb); mature crops (noun). herbivory the act or practice of eating plant material. hydrosphere the area in which water exists; for the purpose of this module, this sphere includes all liquid water on Earth, such as rivers, lakes and oceans, all frozen waters such as glaciers, icebergs, and polar icecaps, and all water vapor. Industrial Revolution a major change in the economy during the 1700s that resulted from the increased use of energy for new power-driven machinery. irrigate to artificially supply with water. lithosphere the area in which all of the cold; hard solid rock of the planet's crust (surface), the semi-solid rock underneath the crust, and the liquid rock near the center of the planet exist; note that many geologists reserve the use of this term to refer to the crust of Earth.. micronutrients elements required in trace amounts by organisms for normal life and activity. Milankovitch Theory suggests that past climatic changes are the result of variations in the Earth's orbital characteristics that produce long-term changes in the amount of solar radiation reaching the Earth's atmosphere and surface. negative feedback mechanism process by which the "cause" of a change is lessened or dampened by its "effect." nitrification breakdown of nitrogen-containing organic compounds into inorganic nitrate (NO3) and nitrite (NO2). nutrients elements required by organisms for normal life and activity. parts per million (ppm) unit of measure most often used to describe the amount of a particular gas or compound in the air or water; it is the proportion of the number of molecules of the gas or compound out of a million (1,000,000,000) molecules of air or water. photosynthesis the process by which green plants convert solar energy into chemical energy and produce organic (carbon-containing) sugar; 6 CO2 + 6 H2O + sunlight C6H12O6 + ---------> 6 O2. plate tectonics theory that the Earth's lithosphere is broken into large, rigid sections or plates that move horizontally across Earth. positive feedback mechanism process by which the "cause" of a change is increased or amplified by its "effect." precession wobble in Earth's axis that, over a cyclical period of 23,000 years, influences the time at which the earth is closest to and farthest from the sun; ultimately, this affects the timing of the changes of the seasons on Earth. precipitation the movement of liquid or solid water (rain, sleet, snow, etc.) from the atmosphere to the Earth's surface; precipitate (verb). primary nutrients elements required by organisms for normal life and activity for which there are no substitutes; essential elements. remote sensing the science of collecting data without directly contacting its source. respiration The process by which animals oxidize organic (carbon-containing) sugars to convert their chemical energy to heat and release carbon dioxide and water as by-products; it is the same chemical reaction that occurs during combustion and decomposition, 6 O2 + C6H12O6 ------> 6 H2O + 6 CO2. secondary nutrients elements required by organisms for normal life and activity in concentrations lower than primary nutrients, but greater than micronutrients. solar flare an explosion on the surface or in the atmosphere of the sun that releases magnetic energy that accelerates electrons and protons. When these particles crash into the solar atmosphere, their kinetic energy is converted into X-rays and gamma-rays that are detected by orbiting satellites. sunspots cool, dark spots on the sun that result from magnetic storms. stratosphere layer of the atmosphere above the troposphere. transpiration the process by which land plants lose water through their leaves. troposphere layer of the atmosphere closest to the earth's surface, where weather occurs. vernalization a period of cold temperatures required by certain plants before they will produce flowers and mature. water-use efficiency ability of plants to utilize light in the process of photosynthesis while restricting water loss. weather short-term (daily) changes in temperature, wind, and/or precipitation in a region. wetlands typically low-lying areas that are characterized by wet (hydric) soils and water-loving (hydrophyllic) vegetation during at least a portion of the year. yield the amount of a crop produced Glossary ..|.. 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