Science Chapter 1

How much air do we carry every day?

700 kilometers of it.

What makes up the atmosphere?

78 percent nitrogen, 21 percent oxygen, and 1 percent is a mixture of other gases like carbon dioxide.

Global warming

A gradual increase in average global temperature. It is caused by greenhouse gases in the atmosphere, which are in turn caused by human activity such as deforestation and the burning of fossil fuels.

What is the atmosphere?

A mixture of gases that surrounds Earth. It contains oxygen that we desperately need to stay alive and also protects us from harmful rays from the sun.

Atmospheric composition affects air temperature

Air temperature also changes as altitude increases. The temperature differences result mainly from the way solar energy is absorbed as it moves through the atmosphere. Some parts of the atmosphere are warmer because they contain a high percentage of gases that absorb solar energy. Other parts of the atmosphere contain less of those gases and so they are cooler.

What's true about atmospheric temperature of these 4 choices: temperature changes with altitude, temperature is cooler with less gas and air pressure, warmer air temperature has gases that absorb solar energy, or all of the above?

All of the above.

2 billionths

Amount of sun's energy that reaches Earth.

Sea and land breezes

During the day, air over the ocean is cooler and produces an area of high pressure. That cool air flows to the land, producing a sea breeze. During the day, air over the land is warmer. As the warm air rises, it creates an area of low pressure. At night, air over the ocean is warmer. As it rises, it forms an area of low pressure. At night, air over land is cooler and forms an area of high pressure. It moves toward the ocean, producing a land breeze.

20%

Energy absorbed by clouds, ozone, and atmospheric gases.

50%

Energy absorbed by earth's surface.

25%

Energy reflected and scattered by air and clouds.

5%

Energy reflected by Earth's surface.

The effects of acid precipitation on forests

Forest ecology is very complex, so much so that scientists are still trying to fully understand the long-term effects of acid precipitation on groups of plants and their habitats. In some areas of the world, acid precipitation has damaged large areas of forest. The effects of acid precipitation are most noticeable in Eastern Europe, but some swatches of forest have been affected by it in the northeastern U.S. and part of Canada.

What are the four layers of the atmosphere?

From the bottom to the top, the troposphere, the stratosphere, the mesosphere, and the thermosphere.

What does the prefix thermo mean?

Heat, and the thermosphere is the layer where temperatures are the highest.

What does the prefix strato mean?

Layer, and the stratosphere is the layer where gases are layered and don't mix very much.

Industrial air pollution

Many industrial plants and electric power plants burn fossil fuels like coal to produce energy. Burning some types of coal without pollution controls can release large amounts of air pollutants. Some industries also produce chemicals that can pollute the air. Chemical manufacturing plants, auto body shops, oil refineries, and dry-cleaning businesses are all potential sources of air pollution.

What does the prefix meso mean?

Middle, and the mesosphere is the middle layer.

Mountain and valley breezes

Mountain breezes and valley breezes are other examples of local winds caused by an area's geography. Those in mountainous areas may feel a warm afternoon quickly change into a cold night soon after the sun sets. During the day, the sun warms the air by the mountain slopes. That warm air rises up the mountain slopes, creating a valley breeze. At nightfall, the air along the mountain slopes cools. That cool air moves down the slopes into the valley, producing a mountain breeze.

Jet streams

Narrow belts of high-speed winds that blow in the upper troposphere and lower stratosphere. They can reach maximum speeds of an astounding 400 kilometers per hour. They don't follow regular paths around the earth. They affect the movement of storms, so meteorologists can track a storm if they know the location of a jet stream.

Indoor air pollution

Occasionally, the air inside a building can be more polluted than the air outside of it. Ventilation, or the mixing of indoor air with outdoor air, can reduce indoor air pollution. Another way to do that is to limit the use of chemical solvents and cleaners.

Acid precipitation and plants

Plant communities have adapted over long periods of time to the natural acidity of the soil in which they grow. Acid precipitation can cause the acidity of soil to increase. That process, called acidification, changes the balance of a soil's chemistry in a few ways. When the acidity of soil increases, some nutrients get dissolved. Nutrients that plants need for growth get washed away by rainwater. Increased acidity also causes toxic metals, such as aluminum, to be released. Some of those toxic metals are then absorbed by the roots of plants.

The formation of smog

Smog forms when vehicle exhaust and ozone react with sunlight. Local weather patterns and geography can also contribute to the formation of smog. Los Angeles is almost completely surrounded by mountains that trap pollutants and contribute to smog formation.

The allowance trading system

The Allowance Trading System is another initiative to reduce air pollution. In this program, the EPA establishes some allowances for the specific amount of a pollutant that companies can legally release. If a company exceeds their allowance, they have to pay a fine. A company that releases less than its allowance can sell some of its allowance to a company that releases more. Allowances are also available for the public to buy. So, organizations seeking to reduce air pollution can buy an allowance of 1,000 tons of sulfur dioxide, thus reducing the total amount of sulfur dioxide released by industries.

Controlling air pollution from industry

The Clean Air Act requires many industries to use pollution-control devices, such as scrubbers. A scrubber is a device that is used to remove some of the pollutants before they are released by smokestacks. Scrubbers in any coal-burning power plants remove particles such as ash from the smoke. Other industrial plants focus on burning fuel more efficiently so that fewer pollutants get released.

The Coriolis Effect

The apparent curving of the path of a moving object from an otherwise straight path due to Earth's rotation. In the Northern Hemisphere, winds that travel north curve east. In the Southern Hemisphere, the winds curve west.

As altitude increases, air pressure decreases

The atmosphere is held around the Earth by gravity. Gravity pulls gas molecules in the atmosphere toward the Earth's surface, causing air pressure. Air pressure is the measure of the force with which air molecules push on a surface. Air pressure is strongest at the Earth's surface, because more air is above you. As you move farther away from the Earth's surface, fewer gas molecules are above you. So, as altitude, which is the distance from sea level, increases, air pressure decreases.

Radiation balance

The balance between incoming energy and outgoing energy.

Convection current

The circular movement of air created by the cycle of warm air rising and cool air sinking.

Convection

The transfer of thermal energy by the circulation or movement of a gas or liquid. An example is the top bunk being warmer than the bottom bunk.

What is the layer of the atmosphere that we live in?

The troposphere.

Where do auroras, which are caused by electrically charged particles called ions, occur?

The upper mesosphere and lower thermosphere.

What does the prefix tropo mean?

Turning or change, and the troposphere is the layer where gases mix and turn.

Westerlies

Wind belts found between 30 degrees and 60 degrees latitude in both hemispheres that travel from west to east. They carry moist air that can result in rain and snow.

Polar easterlies

Wind belts that go from the poles to 60 degrees latitude in both hemispheres that travel from east to west. They carry cold air that produces snow and freezing weather.

Why air moves

Wind causes air to move because of the differences in air pressure.

The horse latitudes

Areas at about 30 degrees north and 30 degrees south where sinking air creates an area of high pressure. The winds there are very weak. Most of the world's deserts are located in them because the sinking air is very dry.

Reducing air pollution from vehicles

A rather large percentage of air pollution in the United States comes from the vehicles we drive. To reduce air pollution from vehicles, the EPA requires car makers to meet a certain standard for vehicle exhaust. Devices such as catalytic converters remove many pollutants from exhaust and help cars meet this standard. Cleaner fuels and more efficient engines have also helped reduce air pollution from vehicles. Car manufacturers are also making cars that run on fuels other than gasoline. Some of these cars run on hydrogen or natural gas. Hybrid cars, which are becoming more common, use electric power and gasoline to reduce emissions. Another way to reduce air pollution is to use public transportation, walk to your destination, or carpool.

The Doldrums

An area around the equator where the trade winds of both hemispheres meet. There are very little winds there because the rising, warm air creates an area of low pressure. "Doldrums" means dull or sluggish.

Water vapor

An invisible gas that can change to solid or liquid water depending on atmospheric conditions.

Acid precipitation and aquatic ecosystems

Aquatic organisms have adapted to live in water with a specific range of acidity. If acid precipitation increases the acidity of a lake or stream, aquatic plants, fish, and other aquatic organisms can possibly die. The effects of acid precipitation on lakes and rivers are absolutely the worst in the spring, when the acidic snow that built up in the winter melts and acidic water flows into lakes and rivers. A rapid change in a body of water's acidity is called acid shock. Acid shock can sadly cause large numbers of fish to die. Acid shock can also affect the delicate eggs of fish and amphibians. To reduce the effects of acid precipitation on aquatic ecosystems, some communities spray powdered lime on acidified lakes in the spring, which reduces the acidity of the lakes. Lime, which is a base, neutralizes the acid in the water. Unfortunately, lime cannot be spread to offset all acid damage to lakes.

What does -sphere mean?

Ball.

Air pollution and human health

Daily exposure to small amounts of air pollution can cause serious health problems. Children, elderly people, and people with allergies, asthma, and lung and heart problems are especially vulnerable to the effects of air pollution. The short-term effects of air pollution are immediately noticeable. Coughing, headaches, and increase in asthma-related problems are only a few short-term effects. The long-term effects of air pollution, such as lung cancer, are more dangerous because they may not be noticed until many years after an individual has been exposed to pollutants. Lots of short-term effects are headache; nausea; irritation of eyes, nose, and throat; coughing; upper respiratory infections; worsening of asthma and emphysema. Some long-term effects are emphysema; lung cancer; permanent lung damage, and heart disease. In other words, air pollution is not good for us humans.

Local winds

Local winds usually move short distances and can blow from any direction. They can be caused by local geographic features. During the day, the land heats up faster than the water, so the air above the land becomes warmer than the air above the ocean. The warm land air rises, and the cold ocean air flows in to replace it. At night, the land cools faster than water, so the wind blows toward the ocean. 4 kinds are land breezes, sea breezes, mountain breezes, and valley breezes.

Sources of human-caused air pollution

Human-caused air pollution comes from a wide variety of sources. A huge source of air pollution in the modern world is transportation. Cars contribute about 10 to twenty percent of the human-caused air pollution in the U.S. Vehicle exhaust contains nitrogen oxide, which contributes to acid precipitation and smog formation. However , cleaner gasoline and pollution controls have greatly reduced air pollution from vehicles.

The ozone hole

In 1985, scientists reported a very alarming discovery about the Earth's protective ozone layer. Over the Antarctic regions, the ozone layer was thinning, particularly during the spring. This change was also noted over the Arctic. Chemicals called CFCs were causing ozone to break down into oxygen, which doesn't block the sun's harmful ultraviolet rays. The thinning of the ozone layer creates an ozone hole. The ozone hole allows more UV radiation to reach the Earth's surface. UV radiation is dangerous to organisms because it can cause skin cancer and damages genes.

Cooperation to reduce the ozone hole

In 1987, a group of nations met in Canada and agreed among each other to take action against ozone depletion. Agreements were made to reduce and eventually ban CFC use, and CFC alternatives were quickly developed. Because many countries agreed to take quick, rapid action to control CFC use, and because a technological solution was quickly found, many people consider ozone protection an environmental success story. The battle to protect the ozone layer is not over, however. CFC molecules can incredibly remain active in the stratosphere for 60 to 120 years. So, CFCs released 30 years ago are still destroying ozone today. That means that it will take very many years for the ozone layer to completely recover.

Cleaning up air pollution

Lots of progress has been made in the field of reducing air pollution. For example, in the United States, the Clean Air Act was passed by Congress in 1970. The Clean Air Act is a law that gives the Environmental Protection Agency (EPA) the authority to control the amount of air pollutants that can be released from any source, such as cars and factories. The EPA also checks air quality. If air quality worsens, the EPA can set stricter standards. The Clean Air Act was strengthened in 1990.

Facts about the ionosphere

It is the home of the auroras. In the upper mesosphere and the lower thermosphere, oxygen and nitrogen atoms absorb harmful solar energy. As a result, the thermosphere's temperature rises, and gas particles become electrically charged. Electrically charged particles are called ions. Therefore, this part of the thermosphere is called the ionosphere. In polar regions, those ions radiate energy as shimmering lights that are called auroras. It also reflects AM radio waves. When the conditions are right, an AM radio wave can travel around the world just by reflecting off the ionosphere. Those radio signals bounce off the ionosphere and are sent back to Earth.

Facts about the stratosphere

It is the layer of the atmosphere that lies directly above the troposphere. It is home of 90 percent of the atmosphere's ozone, protecting us from harmful ultraviolet rays that come from the sun. Gases in the stratosphere are layered, and so do not mix as much as gases in the troposphere. The air is also very thin in the stratosphere and contains little moisture. The lower stratosphere is very cold. Its temperature averages negative 60 degrees Celsius, and temperature rises as altitude increases in the stratosphere.

Facts about the troposphere

It is the lowest layer of the atmosphere and lies right next to the earth's surface. It is the densest atmospheric layer, containing about 90 percent of the atmosphere's total mass. It also has the remaining ten percent of our ozone. Almost all of the Earth's water vapor, carbon dioxide, clouds, air pollution, weather, and life-forms are in the troposphere. Differences in density and air pressure cause gases in the troposphere to mix continuously. As altitude increases in the troposphere, temperature decreases.

Facts about the thermosphere

It is the topmost layer of the atmosphere, not counting the exosphere, It is one layer above the mesosphere, two above the stratosphere, and three above the troposphere. Like in the stratosphere, the temperature there increases as altitude does the same. Atoms of oxygen and nitrogen absorb high-energy solar radiation and release thermal energy, which causes temperatures in the thermosphere to be 1,000 degrees Celsius or higher. When you think of an area that has high temperatures, you probably think of somewhere that is hot. Although the thermosphere has very high temperatures, it doesn't feel hot. Heat is different from temperature. Temperature is a measure of the average energy of particles in motion. The high temperature of the thermosphere means that particles in that layer are moving very fast. Heat, however, is the transfer of thermal energy between objects of different temperatures. Particles must touch one another to transfer thermal energy. The space between particles in the thermosphere is so great that particles do not transfer much energy. In other words, the density of the thermosphere is so low that particles do not often collide and transfer energy.

Primary pollutants

Pollutants that are put directly into the air by human or natural activity. Primary pollutants from natural sources include sea salt, dust, volcanic gases, pollen, ash, and smoke from forest fires. Primary pollutants from human sources include dust, smoke, chemicals from paint and other substances, and carbon monoxide. In urban areas, vehicle exhaust is a very common source of primary pollutants.

Secondary pollutants

Pollutants that form when primary pollutants or with naturally occurring substances, such as water vapor. Smog and ozone are examples of secondary pollutants. In the stratosphere, ozone forms a protective layer that absorbs harmful radiation from the sun. However, near the Earth's surface, ozone is a dangerous pollutant that negatively affects the health of organisms.

Acid precipitation

Precipitation such as snow, sleet, or rain that contains acids from air pollution. When fossil fuels are burned, they can release nitrogen oxide and sulfur dioxide into the atmosphere. When those pollutants combine with water in the atmosphere, they form sulfuric acid and nitric acid. Precipitation is actually naturally acidic, but those two acids can make it so acidic that it can negatively affect the environment. In most areas of the world, pollution controls have helped reduce acid precipitation.

Trade winds

The winds that blow from 30 degrees latitude to the equator in both hemispheres. The Coriolis Effect causes them to blow east in the Northern Hemisphere and west in the Southern Hemisphere. Early traders used them to sail from Europe to the Americas. That is how they got their name.

Global winds

The combination of convection cells found every 30 degrees and the Coriolis effect.

Air pollution

The contamination of the atmosphere by the introduction of pollutants from human and natural sources.

What is air pressure?

The measure of the force with which air molecules push down on a surface.

Facts about the mesosphere

The mesosphere is directly above the stratosphere and two layers above the troposphere. It's the coldest layer of the atmosphere, and like in the troposphere, temperatures decrease as altitude increases. Temperatures get as low as negative ninety-three degrees Celsius at the top of the mesosphere. That's -135.40 degrees Fahrenheit!

What is the coldest layer of the atmosphere? Hint: it lies directly below the uppermost layer of the atmosphere.

The mesosphere.

Wind

The movement of air caused by differences in air pressure.

Greenhouse effect

The process by which gases in the atmosphere absorb thermal energy and radiate it back to Earth. It is also the warming of the lower atmosphere and surface of the Earth that occurs when carbon dioxide, water vapor and other gases absorb and reradiate thermal energy.

What layer of the atmosphere contains 90 percent of its ozone?

The stratosphere.

What are the two highest layers of the atmosphere, not including the ionosphere and exosphere?

The thermosphere and the mesosphere.

What is the uppermost layer of the atmosphere?

The thermosphere.

Radiation

The transfer of energy as electromagnetic waves. An example is toasting a marshmallow over a fire.

Thermal conduction

The transfer of energy as heat through a material. An example is touching a hot stove and burning yourself as a result.

Air rises at the equator and sinks at the poles

The uneven heating of the Earth causes differences in air pressure. At the equator, warm air, which is less dense, rises, causing a low pressure. This is because the equator receives more direct solar energy than any other latitudes. Cold air, which is more dense, sinks, causing a high pressure. The polar air then flows down toward the equator.

Pressure belts are found every 30 degrees

They separate convection cells, which are large, circular patterns of air. Pressure belts are bands of high pressure and low pressure. As warm air rises over the equator and moves toward the poles, it begins to cool. At about 30 degrees north and 30 degrees south latitude, some of the cool air begins to sink. Cool, sinking air causes high pressure belts near 30 degrees latitude in both hemispheres. The cool air flows back to the equator where it warms and rises again. At the poles, cold air sinks and moves toward the equator. Air warms as it moves away from the po0les. Around 60 degrees latitude in both hemispheres, the warmer air rises, which creates a low pressure belt. This air flows back to the poles.