Global Winds Wind is the movement of air caused by differences in air pressure. Air rises in areas of high temperatures, like at the Equator, and sinks in areas of cold temperatures, like at the Poles. This causes air to travel the world in circular patterns. The apparent curving of the paths of winds and ocean currents to the Earth’s rotation is called the Coriolis effect

Global Winds The Polar Easterlies are wind belts that extend from the poles to 60 degrees latitude. In North America these wind belts can be responsible for snow and freezing weather. The Westerlies are wind belts found between 30 and 60 degrees latitude in both hemispheres. In North America these wind belts can produce rain and snow. The Trade Winds are the winds that blow from 30 degrees latitude to the equator. The Doldrums is an area where the trade winds from the Northern and Southern hemispheres meet. There is very little wind in this area due to the warm air creating a low pressure area.

At 30 degrees North and 30 degrees South latitude, sinking air causes an area of high pressure. The winds in these areas are weak and are called the Horse Latitudes Jet Streams are narrow belts of high-speed winds that blow in the upper troposphere and lower stratosphere. Pilots take advantage of these to make airplanes fly faster. A Valley Breeze is created when warm air during the day rises to the top of the mountain. A Mountain Breeze occurs at night when the air near the slope of a mountain cools and falls down the mountain.

Air Pollution Air Pollution is the contamination of the atmosphere by the introduction of pollutants from human and natural sources. Pollutants that are put directly in the air are primary pollutants. These include dust, sea salt, volcanic gases, smoke from forest fires, carbon monoxide, chemicals, and others. Secondary pollutants are formed when primary pollutants interact with natural occurring substances, such as water vapor. Ozone and smog are two examples of secondary pollutants

Human-Caused Air Pollution Many industrial plants and electric power plants burn fossil fuels to produce energy. If done without pollution controls, they can release large amounts of pollutants into the air. Chemical manufacturing plants, dry-cleaning businesses, auto body shops, and others are also potential industrial pollutants. Air inside a building can be more polluted than the air outside unless it has proper Ventilation, which is the mixing of indoor and outdoor air.

Acid Precipitation Rain, sleet, or snow that contains acids from air pollution is called Acid Precipitation. This occurs when pollutants mix with water in the atmosphere. Acid Precipitation can effect the acidic balance of soil in a process called acidification. This can have many negative effects on plant life by dissolving important nutrients or releasing toxic metals such as aluminum into the soil which is then absorbed by the roots of plants. Acid Precipitation can also greatly damage the ecosystems of lakes or streams. Animals have adapted to live in specific acidic levels and when that increases they can die. This is especially common in the spring when the melting acidic snow flows into the body of water, rapidly increasing the acidity of the water, which is caused acid shock. To prevent this, some communities spray powdered lime on acidified lakes in the spring, which reduces the acidity level of the water.

The Ozone Hole In 1985, a group of scientists discovered than the ozone layer over the Antarctic was thinning. This was caused by chemicals known as CFC’s, which were causing the ozone to break down into Oxygen, which does not block the suns harmful UV rays. In 1987 a group of nations met in Canada to discuss banning the use of CFC’s. Though they agreed, CFC’s can remain active in the stratosphere for over 100 years, so this will be an issue that will remain for some time.

Air Pollutions Effect on Human Health Exposure to air pollution can have very negative effects on human health. In the short term it can lead to headache, coughing, asthma, and more. Long term is even worse, as it can lead to dangerous diseases such as lung cancer and heart disease. Because of these consequences, a lot of effort has been made to reduce air pollution. The Clean Air Act was passed in 1970, and the Environmental Protection Agency (EPA) works to deal with the problem as best as they can. They have the authority to control the amount to fair pollutants that can be legally released from any source. One method to reduce pollution is the use of devices known as scrubbers in industrial plants. Scrubbers remove pollutants before they are able to be released.

Another effort by the EPA is the Allowance Trading System, which establishes allowances for the amount of a pollutant that companies can release. If they exceed their allowance, they must pay a fine. Since a large percentage of air pollution in the U.S. comes from the vehicles we drive, the EPA has pushed car makers to reduce the exhaust from their cars and to pursue alternative forms of energy such as hydrogen, natural gas, or electricity.