Troposphere
immediately adjacent to the earth's surface
Ranges from 18 km high over equator to 8 km over poles.
Convection currents redistribute heat and moisture around globe.
Tropopause
- boundary that limits mixing between the troposphere and upper zones as air ceases to rise
Weather
short-term, local patterns of temperature, precipitation, humidity, wind, etc.
Climate
long-term (decades, centuries, millennial, etc.) patterns of temperature and precipitation.
Stratosphere
From tropopause up to ~50 km
-almost no water vapor
ozone
O3
-absorbs ultraviolet light, which warms upper part of stratosphere while protecting life on Earth because UV radiation damages living tissues/DNA
-is being depleted due to pollutants
Mesosphere
Middle layer where the temperature diminishes again
Thermosphere
-Begins at 80 km
-Ionized gases and high temperatures
Albedo
reflectivity of solar energy
-Light surfaces reflect a lot (high albedo)
-Dark surfaces absorb a lot (low albedo)
Greenhouse Effect
-A natural phenomena where the atmosphere transmits sunlight while trapping heat.
-This process supports life as we know it.
Greenhouse Gases
gases in atmosphere that retain heat, especially carbon dioxide, water vapor, nitrous oxides, methane, and other substances
latent heat
Energy stored in water vapor
Hadley cell
a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes, typically about 30� north or south
prevailing winds
High and low pressure areas formed by atmospheric circulation generate consistent patterns of air movement on surface
coriolis effect
Winds and currents appear to move clockwise in Northern Hemisphere and counterclockwise in the Southern Hemisphere
Heat capacity
Ability to resist changes in temperature; water higher than land
Monsoon
seasonal reversal of wind patterns caused by differential heating and cooling rates of oceans and continents
Rain shadow effect
When an air mass meets a mountain range, it is forced upwards, cooling and releasing precipitation.
Hurricanes
occur in atlantic ocean
Tornadoes
-swirling funnel clouds over land
Ice cores
collected from glaciers provide series of snapshots of climate history.
Milankovitch cycles
These long-term climate oscillations are explained by regular changes in 1) the shape of Earth's orbit and 2) the tilt of its axis
Intergovernmental Panel on Climate Change (IPCC)
an international group of scientists and governmental representatives from 130 countries reviewed the scientific evidence for climate change.
Carbon Dioxide
-emissions have doubled from 1970 to 2010
-Fossil-fuel burning is the major human caused source
Methane
-ruminants (cows) and rice paddies are major sources
-Absorbs more energy than CO2 .
Nitrous Oxide
-vehicle engines, agriculture are major sources.
-Highly effective at capturing heat energy.
Carbon Trading (cap and trade)
legal limits on emissions are set and countries that want to emit more must purchase emissions credits from others
Carbon Neutral
reducing green house gas emissions to zero.
Primary Pollutants
released directly from the source
Secondary Pollutants
converted to a hazardous form after entering the air and mixing with other air components
Fugitive Emissions
do not go through smokestack
dust from soil erosion, strip mining, rock crushing, building construction/destruction
conventional or criteria pollutants
Sulfur Dioxide
Nitrogen Oxides
Carbon Monoxide
Ozone
Lead
Particulates
Sulfur Dioxide
corrosive gas which reacts with water vapor in the air to cause acid rain
Smog
fog or haze combined with smoke and other atmospheric pollutants
Nitrogen oxides (NxOx)
reactive gases formed when nitrogen is heated >650oC in presence of oxygen, or when nitrogen compounds are oxidized by bacteria.
Carbon Monoxide
Inhibits respiration by binding irreversibly to hemoglobin in the blood
-a colorless, odorless, toxic gas produced by incomplete fuel combustion
Ozone
O3 layer in the stratosphere shields the biosphere by absorbing incoming uv radiation
Lead
is 2/3 of all metallic air pollution; many toxic metals occur as trace elements in fuel, especially coal
Aerosols
solid particles or liquid droplets suspended in the atmosphere
includes ash, soot, lint, smoke, pollen, spores, etc
Volatile Organic Compounds
-Organic chemicals
-Generally oxidized to CO and CO2
-Plants are largest source.
-400 million tones of methane produced by natural wetlands and rice paddies.
Mercury
Dangerous neurotoxin, 75% of human exposure comes from eating fish.
Other toxic metals
Nickel, beryllium, cadmium, arsenic...
Halogens
Fluorine, Chlorine, Bromine,
deplete ozone layer
Toxics Release Inventory
requires manufacturers to report on toxin release and waste management
Aesthetic Degradation
Noise, odor, light pollution
Inversions
occur when a stable layer of warm air lies above cooler air, reversing the normal temperature decline with increasing height, and prevents convection currents from dispersing pollutants.
Grasshopper transport
volatile compounds evaporate from warm areas; travel to poles where they condense and precipitate. Contaminants bioaccumulate in food webs. Whales, polar bears, & sharks have dangerously high levels of contaminants.
Acid precipitation (rain)
deposition of wet acidic solutions or dry acidic particles from the air
Sulfur Removal
Switch from soft coal with a high sulfur content to low-sulfur coal.
Nitrogen Oxides control
Best method is to prevent creation
Staged Burners
Selective Catalysts
Hydrocarbon Control
Use closed systems to prevent escape of fugitive emissions.
Clean Air Act (1963)
First national air pollution control
Clean Air Act (1970)
I-dentified critical pollutants.
-Established ambient air quality standards.
1990 amendments addressed:
-Acid rain
-Urban air pollution
-Toxic emissions
-Ozone depletion
Hydrologic Cycle
water evaporates from moist surfaces, falls as rain or snow, passes through living organisms and returns to the oceans
residence time
The length of time water typically spends in a compartment
Frozen Water
Glaciers, Ice, and Snow
Infiltration
process of water percolating through the soil and into fractures and permeable rocks
Zone of aeration
upper soil layers that hold both air and water
Zone of saturation
lower soil layers where all spaces are filled with water
Water table
top of zone of saturation
Aquifers
porous layers of sand, gravel, or rock lying below the water table
Recharge zones
area where water infiltrates into an aquifer
discharge
Best measure of water volume carried by a river
-The amount of water that passes a fixed point in a given amount of time
Renewable Water Supplies
Consists of surface runoff plus infiltration into accessible freshwater aquifers
Water Stress
occurs when human and ecosystem needs exceed the renewable water supplies, resulting in competition
Withdrawal
Total amount of water removed from a water source. Some of this water will return to the source to be re-used
Consumption
Loss of water due to evaporation, absorption, or contamination. The portion that is withdrawn but does not return to the source.
access to clean water
problem in many countries in the world
subsidence
Withdrawing large amounts of groundwater in a small area causes porous formations to collapse, resulting
Saltwater intrusion
can occur along coastlines where overuse draws the water table low enough to allow saltwater to intrude.
Point Sources
discharge pollution from specific locations
Nonpoint Sources
scattered or diffuse, having no specific location of discharge
Atmospheric Deposition
contaminants carried by air currents and precipitated into watersheds or directly onto surface waters as rain, snow, or dry particles
Coliform bacteria
intestinal bacteria (e.g., E. coli); used to detect water contamination by animal wastes
Biochemical Oxygen Demand
amount of dissolved oxygen consumed by aquatic microorganisms.
Dissolved Oxygen Content
measure of dissolved oxygen in the water
Oligotrophic
bodies of water that have clear water and low biological productivity
Eutrophic
bodies of water that are rich in organisms and organic material
Eutrophication
process of increasing nutrient levels and biological productivity, a normal part of successional change in most lakes
Cultural Eutrophication
increase in biological productivity caused by human activities
Red tides
dinoflagellate blooms - increasingly common in slow-moving and shallow waters.
Nonmetallic Salts
Many salts are non-toxic at low concentrations but can be mobilized by irrigation and concentrated by evaporation, reaching levels toxic to plants and animals.
thermal plume
Disrupts natural ecosystems
Industrial cooling processes often use heat-exchangers to extract excess heat, and then discharge heated water back into original source as a ______________
Natural Disposal
In many poor countries, outdoor urination and defecation is the norm.
-natural processes eliminate waste
-works in low pop densities
Primary Treatment
municipal sewage treatment- physical separation of large solids from the waste stream
Secondary Treatment
municipal sewage treatment- biological degradation of dissolved organic compounds
Tertiary Treatment
municipal sewage treatment- removal of nutrients (nitrates and phosphates) from secondary effluent
U.S. Clean Water Act (1972)
Goal was to return all U.S. surface waters to "fishable and swimmable" conditions
Regulates draining and filling of wetlands