AIR and THE ATMOSPHERE
Layers of the Atmosphere:
What is air?
What makes wind?
Wind is caused by air flowing from high pressure to low pressure. Since the Earth is rotating, however, the air does not flow directly from high to low pressure, but it is deflected to the right (in the Northern Hemisphere; to the left in the Southern Hemisphere), so that the wind flows mostly around the high and low pressure areas.
What makes Weather?
1. The earth is heated unequally
2. It rotates on its axis
3. It orbits the sun
4. Ocean currents
5. Atmospheric convection currents
ALBEDO: amount of sunlight reflected back to space
high albedo causes increased temperatures and increased temperatures change weather patterns
2. It rotates on its axis
3. It orbits the sun
4. Ocean currents
5. Atmospheric convection currents
ALBEDO: amount of sunlight reflected back to space
high albedo causes increased temperatures and increased temperatures change weather patterns
Major Air Currents:
Depend on solar energy. It heats up air and water. Hot air rises, cold air sinks. Same with water.
The Humboldt Current: Brings nutrients from Antarctica to the West Coast of South America
EL NINO:
El Niño is defined as warmer than normal sea-surface temperatures (SSTs) in the tropical Pacific ocean that impact global weather patterns off the coast of South America.
So how does this large pool of warm water impact the atmosphere?
In normal, non-El Niño conditions the trade winds blow toward the west across the tropical Pacific Ocean. These winds pile up warm surface water in the west Pacific, so that the sea surface is about 1/2 meter higher at Indonesia than at Ecuador.
The sea surface temperature is about 8 degrees C higher in the west, with cool temperatures off South America, due to an upwelling of cold water from deeper layers. This cold water is nutrient-rich, supporting a diverse marine ecosystem and major fisheries. Rainfall is found in rising air over the warmest water in the western Pacific, and the east Pacific is relatively dry.
During El Niñothe trade winds relax in the central and western Pacific leading to a movement to the east of the warm pool of water. This warm pool of water moves eastward until it spreads across the entire Pacific Ocean. The normally cool water located off the South American coast is replaced by much warmer waters, and without the trade winds, the upwelling which supplies the cooler sub-surface ocean water is weakened. Rainfall follows the warm water eastward, with associated flooding in Peru and drought in the normally wet regions of Indonesia and Australia. This eastward displacement of the atmospheric heat source overlaying the warmest water results in large changes in the global atmospheric circulation pattern as can be seen in the diagram. This large change in the circulation pattern in turn forces changes in weather in regions far removed from the tropical Pacific, such as Arizona.
Notice the warmer-than-normal Pacific water
Global Ocean Phenomenon: El Nino and La Nina
Major Wind Patterns:
*creates deserts at 30 degree S and N
* causes poor wind circulation at the equator
* are influenced by the earth's rotation (corioilis) and seasons (solar heat absorption changes)
The BIG 6
1. Outdoor primary pollutants
I. OXIDES:
- 1. Sulfur oxides (SOx) - especially sulfur dioxide, SO2 is produced by volcanoes and in coal and petroleum burning.
- 2. Nitrogen oxides (NOx) - especially nitrogen dioxide are emitted from exhaust, and are also produced naturally during thunderstorms.NO2 is one of the most prominent air pollutants.
- 3. Carbon monoxide - is a colourless, odorless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide.
- 4. Carbon dioxide (CO2) - a colourless, odorless, non-toxic greenhouse gas also associated with ocean acidification, emitted from sources such as combustion, cement production, and respiration. It is otherwise recycled in the atmosphere in the carbon cycle.
- II. VOCs
- Volatile organic compounds - VOCs are an important outdoor air pollutant. In this field they are often divided into the separate categories of methane (CH4) and non-methane (NMVOCs). Methane is an extremely efficient greenhouse gas which contributes to enhanced global warming. Other hydrocarbon VOCs are also significant, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukemia through prolonged exposure.
- III. Particulate matter - Particulates, alternatively referred to as particulate matter (PM) or fine particles, are tiny particles of solid or liquid suspended in a gas. Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer.
- IV. Chlorofluorocarbons (CFCs) - harmful to the ozone layer emitted from products currently banned from use.
- V. Ammonia (NH3) - emitted from agricultural processes.
- VI. Odors — such as from garbage, sewage, and industrial processes
- VII. Radioactive pollutants - produced by nuclear explosions, nuclear events, war explosives, and natural processes such as RADON.
2. Outdoor Secondary pollutants include:
- I. Photochemical smog
- Modern smog does not usually come from coal but from vehicular and industrial emissions that are acted on in the atmosphere by ultraviolet light from the sun to form secondary pollutants that also combine with the primary emissions to form photochemical smog.
- II. Ground level ozone (O3) formed from NOx and VOCs. Ozone (O3) is a key constituent of the troposphere. It is also an important constituent of certain regions of the stratosphere commonly known as the Ozone layer.
- III. Peroxyacetyl nitrate (PAN) - similarly formed from NOx and VOCs.
Thermal Inversions keep all the pollutants from leaving the area.
http://www.chaseireland.org/Thermal%20Inversion.htm
3. Indoor Air Pollutants: Can cause (Sick Building Syndrome)
Mold, smoke, radon, CO, asbestos, Pb (lead), cleaners,
4. ACID DEPOSITION (RAIN):
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pH scale:
measures the amount of H+ ions. pH 3 means there are 10 to the -3 H+ ions
5. Ozone Depletion:
Caused by CFCs, methyl chloroform, carbon tetrachloride, halon, methyl bromide all of which attack stratospheric ozone. Negative effects of ozone depletion include increased UV, skin cancer, cataracts, and decreased plant growth.
What is the Ozone Layer:
Ozone is a gas that occurs naturally in our atmosphere. Most of it is concentrated in the ozone layer, a region located in the stratosphere several miles above the surface of the Earth. It plays a vital role by shielding humans and other life from harmful ultraviolet light from the Sun.
Ozone is a gas that occurs naturally in our atmosphere. Most of it is concentrated in the ozone layer, a region located in the stratosphere several miles above the surface of the Earth. It plays a vital role by shielding humans and other life from harmful ultraviolet light from the Sun.
The Chapman Cycle
The stratosphere is in a constant cycle with oxygen molecules and their interaction with ultraviolet rays. This process is deemed a cycle because of its constant conversion between different molecules of oxygen. The ozone layer is created when ultraviolet rays react with oxygen molecules (O2) to create ozone (O3) and atomic oxygen (O). This process is called the Chapman Cycle.
It is important to keep in mind that ozone is constantly being created and destroyed by the Chapman Cycle and that these reaction are natural processes, which have been taking place for millions of years. Because of this, the thickness the ozone layer at any particular time can vary greatly. It is also important to know that O2 is constantly being introduced into the atmosphere through photosynthesis, so the ozone layer has the capability of regenerating itself.
Chemistry of Ozone Depletion CFC molecules are made up of chlorine, fluorine and carbon atoms and are extremely stable. This extreme stability allows CFC's to slowly make there way into the stratosphere (most molecules are not around long enough to cross into the stratosphere from the troposphere). This prolonged life in the atmosphere allows them to reach great altitudes when photons are more energetic. When the CFCs come into contact with these high energy photons their individual components are freed from the whole. The following reaction displays how Cl atoms have an ozone destroying cycle:
Cl + O3 → ClO + O2
ClO + O → Cl + O2
________________
O3 + O → 2O2 : Overall reaction
Chlorine is able to destroy so much of the ozone because it is a catalyst. Chlorine initiates the break down of ozone and combines with a freed oxygen to create two oxygen molecules. After each reaction, chlorine is able to begin the destructive cycle again with another ozone molecule. One chlorine atom can thereby destroy thousands of ozone molecules. Because ozone molecules are being broken down they are unable to absorb any ultraviolet light so we experience more intense UV radiation at the earths surface.
The Ozone Hole
The ozone hole over Antarctica is formed by a slew of unique atmospheric conditions over the continent that combine to create an ideal environment for ozone destruction.
The stratosphere is in a constant cycle with oxygen molecules and their interaction with ultraviolet rays. This process is deemed a cycle because of its constant conversion between different molecules of oxygen. The ozone layer is created when ultraviolet rays react with oxygen molecules (O2) to create ozone (O3) and atomic oxygen (O). This process is called the Chapman Cycle.
It is important to keep in mind that ozone is constantly being created and destroyed by the Chapman Cycle and that these reaction are natural processes, which have been taking place for millions of years. Because of this, the thickness the ozone layer at any particular time can vary greatly. It is also important to know that O2 is constantly being introduced into the atmosphere through photosynthesis, so the ozone layer has the capability of regenerating itself.
Chemistry of Ozone Depletion CFC molecules are made up of chlorine, fluorine and carbon atoms and are extremely stable. This extreme stability allows CFC's to slowly make there way into the stratosphere (most molecules are not around long enough to cross into the stratosphere from the troposphere). This prolonged life in the atmosphere allows them to reach great altitudes when photons are more energetic. When the CFCs come into contact with these high energy photons their individual components are freed from the whole. The following reaction displays how Cl atoms have an ozone destroying cycle:
Cl + O3 → ClO + O2
ClO + O → Cl + O2
________________
O3 + O → 2O2 : Overall reaction
Chlorine is able to destroy so much of the ozone because it is a catalyst. Chlorine initiates the break down of ozone and combines with a freed oxygen to create two oxygen molecules. After each reaction, chlorine is able to begin the destructive cycle again with another ozone molecule. One chlorine atom can thereby destroy thousands of ozone molecules. Because ozone molecules are being broken down they are unable to absorb any ultraviolet light so we experience more intense UV radiation at the earths surface.
The Ozone Hole
The ozone hole over Antarctica is formed by a slew of unique atmospheric conditions over the continent that combine to create an ideal environment for ozone destruction.
- Because antarctica is surrounded by water, winds over the continent blow in a unique clockwise direction creating a so called "polar vortex" that effectively contains a single static air mass over the continent. As a result, air over Antarctica does not mix with air in the rest of the earth's atmosphere.
- Antarctica has the coldest winter temperatures on earth, often reaching -110 F. These chilling temperatures result in the formation of polar stratospheric clouds (PSC's) which are a conglomeration of frozen H2O and HNO3. Due to their extremely cold temperatures, PSC's form an electrostatic attraction with CFC molecules as well as other halogenated compounds
6. Greenhouse Effect: Climate Change
When sun's energy gets trapped in the earth's atmosphere. We need this to keep warm!!! BUT, too much trapped Energy causes global temps to increase. (Global Warming/CLimate Change)
Greenhouse Gases
Of all the greenhouse gases, carbon dioxide is present at the highest concentration by far. Based on 1990 concentrations, carbon dioxide is said to be responsible for almost 60% of the total greenhouse effect when efficiency and concentration are considered. Its concentration is increasing in the atmosphere due in large part to the extensive burning of coal and other fossil fuels for energy production. Another cause of CO2 increase is the destruction of large areas of trees that leads to a reduction in use of carbon dioxide for photosynthesis.
Methane is present in the atmosphere at less than 1% the levels of carbon dioxide, however it is 25 times more efficient as a greenhouse gas. It contributes to a little over 10% of the total greenhouse effect based on current concentrations. The primary anthropogenic sources are combustion of fossil fuel, and the decomposition of organic materials associated with wetlands, rice paddies, and livestock manure.
Nitrous oxide also occurs in low concentrations relative to carbon dioxide, but it is 230 times more efficient as a greenhouse gas. These factors combine to make it a 6% contributor to total the greenhouse effect. The primary anthropogenic sources are fossil fuel combustion, fertilizers, and deforestation.
The only major greenhouse gases that are not naturally occurring are thechlorofluorocarbons. They come solely from anthropogenic sources such as the production and/or use of foams, aerosols, refrigerants, and solvents. They are present at an extremely low concentration in the atmosphere, however they are 15,000 times more efficient as a greenhouse gas relative to carbon dioxide. As a result, they contribute to approximately 25% of the total greenhouse effect based on 1990 concentrations.
Of all the greenhouse gases, carbon dioxide is present at the highest concentration by far. Based on 1990 concentrations, carbon dioxide is said to be responsible for almost 60% of the total greenhouse effect when efficiency and concentration are considered. Its concentration is increasing in the atmosphere due in large part to the extensive burning of coal and other fossil fuels for energy production. Another cause of CO2 increase is the destruction of large areas of trees that leads to a reduction in use of carbon dioxide for photosynthesis.
Methane is present in the atmosphere at less than 1% the levels of carbon dioxide, however it is 25 times more efficient as a greenhouse gas. It contributes to a little over 10% of the total greenhouse effect based on current concentrations. The primary anthropogenic sources are combustion of fossil fuel, and the decomposition of organic materials associated with wetlands, rice paddies, and livestock manure.
Nitrous oxide also occurs in low concentrations relative to carbon dioxide, but it is 230 times more efficient as a greenhouse gas. These factors combine to make it a 6% contributor to total the greenhouse effect. The primary anthropogenic sources are fossil fuel combustion, fertilizers, and deforestation.
The only major greenhouse gases that are not naturally occurring are thechlorofluorocarbons. They come solely from anthropogenic sources such as the production and/or use of foams, aerosols, refrigerants, and solvents. They are present at an extremely low concentration in the atmosphere, however they are 15,000 times more efficient as a greenhouse gas relative to carbon dioxide. As a result, they contribute to approximately 25% of the total greenhouse effect based on 1990 concentrations.
Effects of Air Pollution:
On human
health
- asthma,
allergies, respiratory disease, cancer, ozone depletion
On the environment
- acid
deposition (acid rain); global climate change; heavy metal leeching and then bioaccumulation
LAWS:
1. Clean Air Act:
Set emission standards for cars, and limits for release of air pollutants.
2. Kyoto Protocol:
Controlling global warming by setting greenhouse gas emissions targets for developed countries.
3. Montreal Protocol:
phase out of ozone depleting substances.
Everything you need about the atmosphere is here!!
http://www.geol.umd.edu/~jmerck/geol100/lectures/33.html
Global Warming Video
Melting Ice Article
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