ch.15, 16,17
The blue planet
71% of Earth's surface is water •97.5% of Earth's water is in the oceans •Only 2.5% is considered fresh water:relatively pure and free from salts.
air and altitude
Air generally becomes colder as altitude rises. •Since warm air rises, vertical mixing results, and air pollution is carried away from its source.
downwelling
Areas where surface currents converge creates downwelling which transports warm surface water to deeper waters, providing an influx of dissolved oxygen and "burying" carbon dioxide from the atmosphere.
atmospheric deposition
Can take place by any form of precipitation—acid rain, fog, gases, or the deposition of dry particles.
winds
Cause severe erosion of soils & spread air pollution •Worsened by desertification & unsustainable farming practices that strip vegetation from the soil
convective circulation
Created by increased evaporation causes air near the Earth's surface to be warmer and moister. •Warm air, being less dense, rises and creates vertical currents. •As air rises, it cools, causing moisture to condense and fall down as rain. •The cooler, denser air sinks, and the cycle repeats.
solar radiation
Depending on the angle, Solar radiation's most intense near the equator, and weakest near the poles.
Improving indoor air quality
Drying wood before burning •Cooking outdoors •Shifting to less-polluting fuels, such as natural gas •Installing hoods, chimneys, cooking windows to increase ventilation •Residents of developed countries can reduce their exposure by not smoking, testing for radon and mold spores, and minimizing exposure to sources of VOCs.
ambient air quality standard
Each pollutant has an ambient air quality standard, which sets the maximum allowable concentration for each pollutant in the air
Heat
Heat from the sun & wind stirring causes the first 150 m of ocean water to have about the same density. •Below 150 m is the pycnocline where density rapidly increases with depth.
ozone hole
In 1985, researchers detected that an area of thinned ozone concentration called the ozone hole was forming every spring over Antarctica. •High-altitude polar stratospheric clouds containing nitric acid were breaking CFCs down into chlorine, which was then being released in the spring when the sun broke up the clouds. •Elevated UV levels could promote skin cancer and damage plant life.
ozone depleting substances
In the 1980s, scientists discovered that human-made airborne chemicals called ozone-depleting substances were causing the degradation of the ozone layer.
indoor air pollution
Indoor air generally contains a greater concentration of pollutants, called indoor air pollution, than what is found outdoors. Many early steps taken to reduce energy consumption, such as limiting ventilation and installing windows that do not open, worsened indoor air pollution.
lakes and ponds
Lakes and ponds are bodies of standing surface water. Ponds and lakes can change over time as rivers and streams bring them nutrients. Lakes or ponds can transition to eutrophic: high-nutrient, low-oxygen conditions.
hadley cells
Near the equator, solar radiation sets in motion a pair of convective cells. The rapid rising and expansion of air due to intense sunlight gives rise to tropical rainforests. •The now-dry air diverges and moves north and south, before cooling and descending at around 30 degrees latitude, producing subtropical deserts.
oceans
Occupy most of the hydrosphere. •Influence the atmosphere & lithosphere. •Encompass much of the biosphere.
primary pollutants
Pollutants released directly from a source •Ex: Ash from a volcano, sulfur dioxide from a power plant, or carbon monoxide from car exhaust
runoff
Precipitation & melting snow/ice that flows over land •Converges in low-lying areas, forming streams, which can merge into rivers, eventually reaching a lake or ocean.
secondary pollutants
Primary pollutants that react with each other or components of the atmosphere •Ex: Ozone, which is formed from pollutants in urban smog
volcanoes
Release particulate matter and sulfur dioxide into the stratosphere •Can cause global cooling if sulfur dioxide reacts with water and oxygen to form aerosols that block sunlight in the stratosphere
VOCs (volatile organic compounds)
Released by: plastics, oils, perfumes, paints, adhesives, cleaning fluids, new furnishing, new carpeting, laser printers, and fax machines. •Indoors, they exist in low concentrations and individuals are exposed to mixtures of many different types.
fires
Residential development in fire-prone regions (L.A.) leads to costly damage when fires occur; releases pollution •Suppression of fires causes fuel to build up in fire-prone areas causing extra devastating fires when they occur
tobacco smoke
Smoking cigarettes irritates the eyes, nose, and throat, while worsening asthma and increasing the risk of cancer and lung disease.
salinity varies across the ocean
Surface ocean waters near the equator have less salt due to high precipitation levels. •High latitudes have more salt because of more evaporation than precipitation. •Coastal waters are less saline due to freshwater runoff.
airborne pollutants
Technologies such as baghouse filters, electrostatic precipitators, and scrubbers physically remove airborne pollutants from smokestacks.
Temperatures
Temperatures tend to decrease with depth due to lack of sunlight •Colder, saltier water is the most dense, so it tends to sink. •Warmer, less-salty water is lighter and tends to remain near the surface.
seasons and daylight
The Earth is tilted on its axis by about 23.5 degrees, resulting in the Northern and Southern Hemispheres being tilted toward the sun for half of each year. •This creates seasonal differences in temperature and amount of daylight in areas away from the equator.
inversion layer
The band of air where temperature rises with altitude since the relationship is the inverse of normal.
front
The boundary between air masses that differ in temperature and moisture.
living organisms
The most widespread source of indoor air pollution may be living organisms. •Tiny dust mites can worsen asthma and cause allergies. •Fungi, mold, and mildew spores can cause allergies, asthma, and other respiratory ailments. •Airborne bacteria can cause diseases.
Radon
The presence of radon is largely the result of natural geology and varies from region to region. •Radon is a colorless, odorless gas, and can only be detected with a special air testing kit. A radioactive gas that results from the natural decay of uranium in soil, rock, and water.•Radon rises through the ground and infiltrates water. •Radon is the second-leading cause of lung cancer.
halocarbons
The primary ozone-depleting substances. synthetic compounds derived from hydrocarbons where hydrogen atoms are replaced by atoms of chlorine, fluorine, or bromine.
water cycle
These interactions create a web of interconnected freshwater and marine aquatic ecosystems. •What happens in one system affects others, even those far away
outdoor air pollution
Though public policy and improved technology have helped reduce outdoor air pollution, it remains a major health concern.
criteria pollutants
Today, the EPA and state agencies monitor the concentration of 6 criteria pollutants known to pose substantial risk to human health •Include: carbon monoxide, sulfur dioxide, particulate matter, lead, nitrogen dioxide & tropospheric ozone
Currents
Vast flows of water driven by differences in density, heating, cooling, gravity, and wind. Surface currents can be rapid and powerful, influencing climate, nutrient distribution, and pollution. Surface winds and heating also create vertical currents in seawater.
temperature inversion
When a layer of cool air becomes trapped beneath warm air, preventing any vertical mixing from occurring. Often occur in valleys, as nearby mountains block morning sunlight, creating cooler air in their shadow.•This traps pollution near the ground.
ozone
a highly beneficial gas in the stratosphere, shielding the Earth's surface from harmful UV radiation from the sun.
smog
a mixture of air pollutants that can accumulate as a result of fossil fuel combustion, especially traffic is heavy
El Niño-Southern Oscillation (ENSO)
a systematic shift in atmospheric pressure, sea surface temperature, & ocean circulation in the tropical Pacific Ocean. •Under normal conditions, prevailing winds blow from east to west alongthe equator, forming a large convective loop in the atmosphere. •This causes a "pile-up" of warm water to form near Indonesia, fueling storms in that region. •ENSO cycles occur every 2-8 years.
tropospheric ozone
also called ground-level ozone, is a secondary pollutant created by the reaction of NOx and VOCs in sunlight. •Ozone is an unstable molecule that can injure living tissues and cause respiratory problems.
Montreal Protocol
an international treaty signed in 1987 •Countries agreed to cut CFC production in half by 1998 •Additional halocarbons were restricted
ocean water
approximately 96.5% water by mass, with the rest consisting of ions from dissolved salts. •The salts arise from runoff and wind that carries salts and sediments into the oceans.
Volatile organic compounds (VOCs)
are carbon-containing chemicals emitted by vehicle engines and solvents. •Examples include methane, propane, and octane. •VOCs react to produce secondary pollutants, such as smog.
recharge zone
area where water can infiltrate through the surface and reach the aquifer.
floodplain
areas near a river's course that are flooded periodically •Frequent flooding and deposition of soil makes soils especially fertile with thriving plant communities.
climate
atmospheric conditions in a location over long periods of time (years or longer)
weather
atmospheric conditions in a location over short time periods (weeks or shorter)
trade winds
blow from E to W between the equator and 30° latitude
westerlies
blow from W to E between 30° and 60° latitude
troposphere
bottom layer providing the air we breathe and driving weather. •Air gets colder with altitude, stabilizing around -52°C at the tropopause.
sulfur dioxide
colorless gas with strong odor •Produced from coal fired powerplants & industry •Causes atmospheric reaction to form sulfuric acid leading to acid rain
carbon monoxide
colorless, odorless gas produced by the incomplete combustion of fuel •Vehicles and engines are the biggest sources •Binds to hemoglobin in red blood cells, preventing it from binding to and transporting oxygen
high-pressure systems
contain cool air that descends and spreads outward.
low pressure
contain warm air that rises and draws air inward toward the center. •Cold air, being denser, tends to wedge underneath the warm air, which then rises and forms clouds and thunderstorms.
industrial smog
contains carbon dioxide, carbon monoxide, mercury, & sulfur from burning fossil fuels •Sulfur reacts with oxygen and water to form sulfuric acid in the atmosphere.
ocean floor
contains underwater volcanoes, steep canyons, and the Mariana Trench, which is deeper than Mount Everest is high.
convective air currents
contribute to broad climate patterns.
catalytic converters
convert hydrocarbons, CO, and NOx into carbon dioxide, water vapor, and nitrogen gas
coriolis effect
deflects objects to the right in the northern hemisphere and the left in the southern, resulting in curving wind patterns
clean air act of 1990
established the Acid Rain Program to fight acid deposition. This program set up an emissions trading program for sulfur dioxide, allocating permits for SO2 pollution and allowing emitters to buy, sell, or trade these allowances. •This created a strong economic incentive to reduce emissions. pH of precipitation improved significantly since the passage of the law.
nitrogen oxide
family of compounds that include nitric oxide and nitrogen dioxide •Produced when atmospheric nitrogen and oxygen combine during engine combustion •Contribute to smog, acid deposition, and ozone depletion
atmospheric pressure
force per unit area produced by a column of air; at higher altitudes due to the lower number of air molecules. •Averages 14.7 lb2 at sea level
tornadoes
form when a mass of warm air meets a mass of cold air, and the warm air rises rapidly, setting a powerful convective current in motion. •If high and low altitude winds are blowing in different directions, the air may begin to rotate, forming a tornado.
hurricanes
form when winds rush into low pressure systems containing warm, moist air from tropical oceans. •Due to the Coriolis effect, hurricanes move counterclockwise in the northern hemisphere. •The rapid intake of warm, moist air leads to heavy amounts of precipitation.
residence time
he amount of time a pollutant spends in the atmosphere before settling to the ground
air pollution
he release of air pollutants: gases and particulate material added to the atmosphere that can affect climate or harm people and other living things.
nitrogen dioxide
highly-reactive reddish-brown, foul-smelling gas contributing to smog & acid precipitation; created atmospherically from nitric oxide
Hadley, Ferrel, Polar Cells
interact with Earth's rotation to produce bands of wind patterns that alternate directions.
lead
is a heavy metal that can enter the atmosphere as a particulate pollutant as a result of vehicles burning leaded gasoline or metal smelting.
particulate matter
is composed of solid or liquid particles small enough to be suspended in the air. •Can be a primary pollutant or secondary pollutant •Classified by size: PM10 particles are less than 10 microns in diameter; PM2.5 particles are less than 2.5 microns in diameter.
surface water
is located atop Earth's surface, such as in a river or lake. Surface water becomes groundwater by infiltration.
water
is renewed and recycled as it passes through the water cycle.
groundwater
is water beneath the surface that resides within pores in soil or rock. Groundwater becomes surface water through springs. •Keeps rivers flowing & wetlands moist Contained in aquifers: porous, spongelike formations of rock or sand. The largest known aquifer is the Ogallala Aquifer, which is located under the Great Plains of the United States.
continental shelves
it beneath the shallow waters bordering the continents. •The shelf-slope break is the drop-off point where the continental slope angles more steeply downward. •Wherever reefs, volcanism, or other processes create physical structures underwater, habitat is formed for underwater life.
oligotrophic
lakes and ponds that are low in nutrients and high in oxygen.
ferrel and polar cells
lift air and create precipitation around 60 degrees latitude north and south, causing air to descend at 30 degrees latitude and at the poles. •This creates another band of moist ecosystems around the 60 degree latitude.
short residence times
localized impacts over short periods
long residence times
long-term regional or global effects
Sunlight
most intense when it meets the surface at a perpendicular angle. •Minimizes the amount of atmosphere it must pass through before reaching the surface.
Air
moves dynamically within the lower atmosphere as a result of differences in air pressure, density, relative humidity, and temperature. •Gravity pulls air toward the Earth's surface, causing it to be more dense at lower altitudes. •The temperature of air also varies with location and time (the sun rays strike some areas more directly than others)
stratosphere
much drier and less dense than the troposphere; very little vertical mixing. •Air warms with altitude due to absorption of sunlight by the ozone layer: protects living organisms from UV damage from the sun.
doldrums
near the equator; receives few winds
warm fronts
occur where warm, moist air replaces cool, dry air. •Some of the warm air rises and releases precipitation as it cools and condenses.
cold front
occurs where a mass of cold, dry air replaces warm, moist air.
La nina
opposite of El Niño events; unusually cold waters rise to the surface and extend westward, causing winds blowing to the west to strengthen.
photochemical smog
orms when sunlight drives chemical reactions between primary pollutants and atmospheric compounds, producing a mixture of over 100 different chemicals •Ozone is the most abundant, and NO2gives the smog a brownish haze color. •Windless, warm, sunny days provide ideal conditions for the formation of photochemical smog.
rural areas
people may be exposed from pollution from sources such as: •Airborne pesticides from farms•Industrial pollutants that drift from cities •Methane, hydrogen sulfide, and ammonia from animal waste in large feedlots •Fumes from natural gas extraction sites
upwelling
pulls cold, deep, nutrient-rich water to the surface. •Upwellings will occur where strong winds blow away from or parallel to coastlines and in areas where surface currents diverge.
relative humidity
ratio of water vapor within air at a given temperature to the maximum amount it could hold.
Clean Air Act (1970)
sets standards for air quality & encourages emissions standards for automobiles and other point sources •States are required to monitor emissions for air quality and develop, implement, and enforce their own regulations to comply with the law •State & local agencies monitor/report to the EPA emissions of 6 major pollutants
toxic air pollutants
substances known to cause cancer; reproductive defects; or neurological, developmental, immune system, or respiratory problems in people and other organisms.
cap and trade program
successfully reduced SO2 emissions in the U.S. by 67%.
wetlands
systems where the soil is saturated with water, often containing standing shallow water. •Can be seasonal, such as vernal pools that form in the snow melt of early spring and dry up later in the summer. •Provide ecosystem services: slowing runoff, reducing flooding, recharging aquifers, & filtering pollutants. •Heavily impacted by human activities, including draining and filling for agriculture, withdrawing water for irrigation, and construction of dams.
watershed
the area of land drained by a river system and its tributaries
acid deposition
the deposit of acid or acid-forming pollutants from the atmosphere on the Earth's surface. Can take place by any form of precipitation—acid rain, fog, gases, or the deposition of dry particles. Occurs as a result of burning fossil fuels and releasing sulfur dioxide and nitrogen oxides, which react with water and oxygen in the atmosphere to form low pH acids. Damages crops, erodes stone vehicles, and corrodes vehicles.•These effects often occur in areas far from the primary pollutants' original source.
El Nino
triggered when air pressure decreases in the eastern Pacific & increases in the western Pacific, weakening the equatorial winds, allowing warm water to flow eastward, and suppressing upwelling along the Pacific coast of the Americas.
water table
upper border of layer in groundwater filled with water.
CFCs
very nonreactive and were assumed to be safe for the environment. •In the stratosphere, CFCs are broken down by UV radiation into chlorine and carbon atoms, which then split many ozone molecules.
thermohaline circulation
worldwide current system; warmer, lower-salinity water moves along the surface and colder, saltier (denser) water moves horizontally below the surface. •Scientists are concerned that an influx in freshwater from melting glaciers in Greenland could disrupt this flow.
