Earth Systems Vocabulary Atmosphere -A thin layer of gases that surround a planet. Barometer- An instrument for measuring atmospheric pressure, used especially in weather forecasting. In the mercury barometer, atmospheric pressure balances a column of mercury, the height of which can be precisely measured. Normal atmospheric pressure is about 14.7 lb per square inch, equivalent to 30 in. (760 mm) of mercury. Carbon Dioxide -(CO2) Gas that makes up less than 1% of Earth’s atmosphere. A greenhouse gas that is released through respiration, decomposition and combustion of fuels. Climate -Average weather over a long period of time. Chlorofluorocarbons -CFCs- a group of chemicals made up of carbon, hydrogen fluorine, and chlorine. Used in refrigerators and air conditioners as a coolant, cleaning solvents and as a propellant in spay cans. This chemical has been banned in many countries because it can deplete the ozone layer. Conduction -The transfer of thermal energy through solids when particles touch. Convection -The movement of matter due to differences in density that are caused by temperature variations. The transfer of energy of heat when a liquid or a gas moves from place to place. El Niño -A temporary change in climate where the surface water in the Eastern Pacific Ocean is unusually warm. Caused by a change in the Trade winds. Electromagnetic spectrum – All types of radiation varying in frequency and wavelengths. Examples include, cosmic-ray photons, gamma rays, x-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, and radio waves. Type of energy that can travel through the void of space. Equator - The imaginary line around the earth's surface that divides the earth into the Northern Hemisphere and the Southern Hemisphere. Zero degrees Latitude. Global Warming -A gradual increase of Earth’s average temperature. Due to high concentrations of greenhouse gases such as carbon dioxide. Greenhouse Gas -a gas composed of molecules that absorb heat from the sun’s radiation, and trap the heat in the Earth’s Atmosphere. Examples are Carbon Dioxide, Methane, Nitrous Oxide, and CFCs. Gulf Stream – Warm ocean current in the Atlantic Ocean that flows North along the Eastern United States, providing moisture for a humid climate. The warm current crosses the Atlantic causing much of Europe to have a mild climate compared to other areas of the same latitude. Latitude – Imaginary lines that circle the globe to indicate distance from the equator. One of the most important factors affecting the Climate in an area. Methane - A compound composed of carbon and hydrogen: CH4. occurs in natural gas and from bacterial decomposition of vegetation in the absence of oxygen (including in the rumens of cattle and other ruminants and in the gut of termites) also is a product of rice farming. Methane is a greenhouse gas that contributes to global warming. Nitrogen gas (N2): Makes up 78% of the Earth’s atmosphere Nitrous Oxide – (N2O) Green house gas that traps 23 times as much heat per molecule of Carbon dioxide. Used in surgery and in combustion engines. Released to the atmosphere through agriculture, livestock, and combustion of fossil fuels. Also depletes the ozone layer and contributes to acid rain. Oxygen (O2): makes up 21% of the Earth’s atmosphere. Almost all of the oxygen in our atmosphere is a product of photosynthesis. Ozone (O3): Molecule made up of 3 oxygen atoms. Ozone Layer -Layer of gas in the Stratosphere. Absorbs some of the sun’s harmful radiation, helping to make earth a safer place to live. Photosynthesis - The process plants use to convert Carbon dioxide to oxygen and sugar, using energy from the sun. CO2 + H2O + energy from the sun C6H12O6 + O2 Radiation -The energy that is transferred as electromagnetic waves. The type of energy transfer that can travel through the void of space. Temperature Inversion – Atmospheric condition in which warm air traps cooler air near the earth’s surface. Can trap smog and pollution making air unsafe to breathe. Trade Winds – Winds that blow from East to West between 30 degrees latitude and the equator. Smog - A form of air pollution produced by the photochemical reaction of sunlight with hydrocarbons and nitrogen oxides that have been released into the atmosphere, especially by automotive emissions. Troposphere: Layer contains most of the air and weather. Stratosphere: layer of the atmosphere that contains the ozone layer which absorbs some of the sun’s harmful radiation. Weather -The atmospheric conditions at a given time and place. Upwelling – Ocean current bringing cold nutrition rich water to the surface near a coast where wind pushes the water away from the shore.