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| Atmosphere | The thin layer of gases that surounds Earth. Consists of 78% nitrogen and 21% oxygen, and 1% other gases. These include permenant gases that remain stable, and variable gases taht vary in concentration from time to time based on natural processes of human activities |
| Layers of the atmosphere, bottom to top | Troposphere (blankets Earth's surface, provides air we breathe and is responsible for weather), Stratosphere (extends 11-50 km above sea level, contains UV radiation-blocking ozone 17-30 km above sea level), Meosphere (extends 50-80km above sea level), Thermosphere (atmosphere's top layer) |
| Atmospheric pressure | Measures theforce per unit area produced by a column of air, also decreases with altitude, because at higher altitudes, fewer molecules are pulled down by gravity |
| Relative humidity | The ratio of water vapor a given volume of air contains to the maximum amount it could contain at a given temerature |
| Effect of solar energy on climate and seasons | Energy from the sun heats air in the atmosphere, drives air movement, helps create the seasons and influenced weather and climate. Solar radiation is highest near the equator |
| How does the tilt of the earth effect the seasons? | Because the Earth is tilted on its axis, the Northern and Southern Hemispheres each tilt toward the sun for half a year, resulting in the seasons |
| Convective circulation | In the atmosphere, warm, less-dense air rises and creates vertical currents. As air rises into regions of lower atmospheric pressure, it expands and cools. Once the air cools it descnds and becomes denser, replacing the warm air that is rising |
| Difference between weather and climate | Weather refers to armospheric conditions over short periods of time within relatively small geographic areas. Climate describes the pattern of atmospheric conditions found across large geographic regions over long periods of time |
| Warm front vs. cold front | A warm front is the boundary along which a mass of warmer, moister air replaces a mass of colder, drier air. A cold front is the boundary along which a colder, drier air mass displaces a warmer, moister air mass. |
| High-pressure vs. low pressure systems | A high-pressure system contains air that descents because it is cool then spreads outward as it nears the ground, typically resulting in fair weather. In a low pressure system, warmer air rises, drawing air inward toward the center of low atmospheric pressure. The rising air expands and cools, and clouds and precipitation usually result |
| What is the Coriolis effect, and how does it impact the movement of winds and currents? | As Earth rotates on its axis, locations on the equator spin faster than locations near the poles. As a result, the north-south air currents of the convective cell appear to be deflected from a straight path as some portions of the globe move faster beneath them than others. This is apparent deflection is the Coriolis effect, which results in curving global wind patterns. These winds and convective circulation work together to maintain ocean currents |
| Wind patterns: doldrums | A region with few winds that lies near the equator |
| Wind patterns: trade winds | Between the equator and 30 degrees latitude are the trade winds that blow east to west |
| Wind patterns: westerlies | From 30-60 degrees latitude, blow from west to east |
| Natural sources of air pollution | Volcanic eruptions release particulate matter, sulfur dioxide and other gases into the troposphere; fires from burning vegetation pollute with soot and gases; winds send dust into the atmosphere |
| Aerosols | Sulfur dioxide reacts with water and oxygen and then condenses into fine droplets called aerosols, which reflect sunlight back into space and thereby cool the atmosphere and surface |
| Point source vs. non-point source | Describes a specific location from which large quantities of pollution are discharged (power plants and factories). Non-point sources are more diffuse and consist of many small sources (cars) |
| Primary pollutants vs secondary pollutants | Primary pollutants (such as soot and carbon monoxide) are pollutants emitted into the troposphere in a form that can cause harm or can react to form harmful substances. Secondary pollutants are harmful substances that are produced when primary pollutants interract with constituents of the atmosphere |
| Clean Air Acts and the EPA | Congress passed the Clean Air Act in 1963, which funded research into pollution control and encouraged emissions standards for cars and stationary point sources. In 1970, Congress revised the law so that the legislation set standards for air quality, imposed limits on emissions for stationary and mobile sources, provided new funds for research etc. As a result of Clean Air Act legislation, the US EPA was formed. The EPA sets nationwide standards for emissions of pollutants and for concentrations of polluntants in ambient air throughout the nation |
| Criteria pollutants | The EPA and the states focus on six different criteria pollutants that are judged to pose especially great threat to human health |
| Criteria pollutants: carbon monoxide | A colorless, odorless gass prodiced primarily by incomplete combistion of fuel |
| Criteria pollutants: sulfur dioxide | A colorless gass with a strong odor. Vast majority results from the combustion of coal for electricity generation and industry. Can form acid precipitation |
| Criteria pollutants: nitrogen dioxide and nitrogen oxides | Nitrogen dioxide is a highly reactive, foul smelling reddish-brown gas that contributes to smog and acid deposition. It belongs to a family of compounds called nitrogen oxides, which result when atmospheric nitrogen and oxygen react at high temperatures created by combustion engines |
| Criteria pollutants: tropospheric ozone | A colorless gas with a strong odor. It is a secondary pollutant that results from interactions of sunlight, heat, nitrogen oxides and volatile carons. It is a moajor component of smog, and poses a health risk due to its instability |
| Criteria pollutants: particulate matter | Composed of solid or liquid particles that are small enough to be suspended in the atmosphere. Can damage respiratory tissues when inhaled |
| Criteria pollutants: lead | A heavy metal that enters the atmosphere as a particulate pollutant. Lead can enter the food chain and accumulate within body tissues |
| Trends in air pollutants since 1970 | Total emissions of the six monitored pollutants have declined despite increased polulation and energy consumption. This is because we have cleaner-burning vehicles and converters taht decrease carbon monoxide. We've also phased out leaded gasoline |
| Industrial smog vs. photochemical smog | Industrial smog (gray-air smog) is formed when coal or oil are combusted. Photochemical smog is produced by light-driven reactions of primary pollutants and normal atmospheric compounds. It irritates eyes, noses and throats |
| Feedlots | The numbers of animals in feedlots and the amounts of waste they produce release dust as well as methane, hydrogen sulfide, and ammonia into the atmosphere. These gasses smell bad, and ammonia contributes to nitrogen deposition |
| Impact of CFC's on the ozone | CFCs release chlorine atoms that split the ozone |
| Hole in the ozone layer | Ozone level over Antarctica had declined by 40-60%. Causes skin cancer, harms crops and decreases ocean productivity. Due to Montreal Protocol, 180 nations agreed to cut CFC productions so now the ozone layer is beginning to recover. |
| Acid rain: causes | Originates from burning fossil fuels that release sulfur dioxide and nitrogen oxides. These compounds react with water to form sulfuric and nitric acids. |
| Acid rain: effects | Nutrients are leached from topsoil, so soil chemistry is changed. Metal ions (aluminum, zinc, etc.) are converted into soluble forms that pollute water. Widespread tree mortality. Affects surface water and kills fish. Damages agricultural crops. Erodes stone buildings, corrodes cars, erases writing on tombstones |
| Global climate change | Describes trends and variations in Earth’s climate, involving aspects such as temperature, precipitation and storm frequency |
| Climate change and global warming | Global warming is one aspect of climate change. It refers to an increase in Earth’s average temperature. Earth’s climate has varied naturally through time, but the rapid climatic changes taking place now are due to human activity: fossil fuels, combustion, and deforestation. |
| What three sources exert more influence on climate than all others? | The sun (provides heat), the atmosphere (absorbs 70% of incoming solar radiation) and the oceans (shape climate by storing and transporting heat and moisture) |
| Greenhouse gasses | Atmospheric gases that absorb infrared radiation: water vapor, ozone, carbon dioxide, nitrous oxide, methane, chlorofluorocarbons (CFCs). Greenhouse gases differ in their ability to warm the troposphere and surface |
| Greenhouse effect | After absorbing radiation, greenhouse gases re-emit infrared energy. Some energy travels back downward, warming the atmosphere and planet’s surface. |
| Global potential of greenhouse gasses | The relative ability of one molecule of a given greenhouse gas to contribute to warming. Expressed in relation to carbon dioxide (potential = 1). Hydrochlorofluorocarbons are 12,000 times as potent as carbon dioxide |
| Greenhouse gases: Carbon dioxide | Not the most potent greenhouse gas, but the most abundant. Human activities have boosted the atmospheric concentrations to their highest levels in over 650,000 years. |
| Greenhouse gases: Methane | Comes from fossil fuel deposits, livestock, landfills, and crops such as rice |
| Greenhouse gases: Nitrous oxide | Comes from feedlots, chemical manufacturing plants, auto emissions, and synthetic nitrogen fertilizers |
| Greenhouse gases: CFC's (Halocarbon gases) | Human-made compounds derived from simple hydrocarbons in which hydrogen atoms are replaced by halogen atoms. They are now declining |
| Greenhouse gases: water vapor | The most abundant greenhouse gas and contributes most to the greenhouse effect. Could increase cloudiness, which might slow global warming by reflecting more solar radiation back into space. |
| Radioactive forcing | The amount of change in thermal energy that a given factor causes. Scientists use radioactive forcing to measure the degree of impact any given factor exerts on earth’s temperature. |
| Milankovitch cycles | Periodic changes in Earth’s rotation and orbit around the Sun. They trigger long-term climate variation such as periodic glaciation |
| How does the earths orbit and tilt relate to long term climate effects | Due to the Milankovitch cycles, which modify patterns of atmospheric heating, and trigger long-term climate variation. This includes periodic episodes of glaciation. |
| Solar output | Drives temperature change on Earth’s surface. The Sun varies in the radiation it emits. Variation in solar energy (i.e., solar flares) has not been great enough to change Earth’s temperature |
| Oceans role in absorbing carbon dioxide | The oceans hold 50 times more carbon than the atmosphere when the gas dissolves directly in water and when marine phytoplankton use it for photosynthesis |
| El Nino/Southern Oscillation: what impact do they have on climate | El Nino and La Nina events alter weather patterns from region to region in diverse ways, often leading to rainstorms and floods in dry areas and drought or fire in moister areas |
| Ocean (Thermohaline) circulation | A worldwide current system in which warmer, fresher water moves along the surface; and colder, saltier water moves deep beneath the surface. Warm surface water carries heat to Europe |
| North American Deep Water | The deep portion of the thermohaline circulation, consisting of dense, cool water that sinks |
| Impact on climate | If Greenland’s ice melts, freshwater runoff would dilute ocean waters, making them less dense, and stopping NADW. Some data suggest thermohaline circulation is slowing. If it stopped, Europe would rapidly cool, as shown in The Day After Tomorrow |
| How can ice cores tell us about past climate | Trapped bubbles in ice cores show atmospheric composition, greenhouse gas concentration, temperature trends, snowfall, solar activity, and frequency of fires |
| Computer models and predictions of future climate change | Climate models are programs that combine what’s known about atmospheric circulation, ocean circulation, atmospheric-ocean interactions and feedback cycles to simulate climate processes. They are becoming more reliable at predicting climate change. |
| Impacts of climate change on the Arctic | Ice caps are melting, polar bears are starving, storms are increasing, sea ice is thinning |
| Expected changes in precipitation patterns | Some regions are receiving more precipitation than usual, and others are receiving less. Droughts have become more frequent and severe, harming agriculture, promoting soil erosion, reducing drinking water supplies, and encouraging forest fires. Heavy rains have contributed to flooding, killing people, destroying homes, and inflicting billions of dollars in damage. |
| Disappearance of glaciers | Mountaintop glaciers are disappearing. In Glacier National Park, only 27 of 150 glaciers remain. Melting of the Greenland ice sheet is accelerating. As ice melts, darker, less-reflective surfaces are exposed and absorb more sunlight, causing more melting, leading to decreased albedo |
| Sea level rise | As glaciers and ice melt, increased water will flow into the oceans. As oceans warm, they expand. This leads to beach erosion, coastal floods, and intrusion of salt water into aquifers |
| Ecosystems and global warming | Organisms cannot adapt fast enough, as global warming modifies temperature-dependent phenomena like timing of migration, breeding, etc. Spatial shifts in the range of organisms (animals and plants will move towards the poles or upward in elevation). 20-30% of all species will be threatened with extinction. Plants act as carbon sinks; fewer plants means more CO2 in the atmosphere |
| Coastal communities | Are the most vulnerable to storm surge (temporary and localized rise in sea level brought on by high tides and winds associated with storms) |
| Economic impacts | Costs will outweigh benefits. Widen the gap between rich and poor. Will cost 1-5% GDP on average globally. Poor nations will lose more than rich ones |
| Ocean Iron experiment as a possible solution to climate change | Oceans absorb carbon from atmosphere, plankton absorb that carbon and return it to the sediment. The ocean iron experiment says you can take iron to parts of the ocean where it is limited, and it will cause an algal bloom that will remove carbon from the sediment |
