Sr. High Education

Atmospheric Composition

The Earth's atmosphere is mostly made up of nitrogen and oxygen. In fact, these two gases contribute to about 99% of the total atmospheric composition. The trace gases such as methane, carbon dioxide, and even water vapor make up the remaining 1%. This last 1% contributes heavily to the warming of our atmosphere, and this will be discussed later on in the Greenhouse Gases section. In this section though, one can find out about our atmospheric composition and the layers of the atmosphere. Once finished with this section, one should be able to differentiate between the troposphere and the stratosphere, and one should be able to list off the major constituents of our atmosphere. To get started on the research, please click on one of the links below and good luck!

1. Atmospheric Composition
2. Layers of the Atmosphere

Greenhouse Gases

When one hears someone talk about the greenhouse effect, or global warming, it is often associated with negativity. However, it is because of these processes that there exists life on Earth. Examples of greenhouse gases are carbon dioxide and methane. These gases are produced naturally in our atmosphere and they help by raising Earth's average temperature about 40 degrees. The occurs due to a process called the greenhouse effect. Greenhouse gases are floating around in the atmosphere, and when uv rays from the Sun collide with these gas particles, most of the uv is absorbed. This absorption traps the heat inside our atmosphere, causing it to heat up! However, within the past 100 years, man has contributed to this heating-up process by introducing more and more greenhouse gases into the atmosphere via automobiles, factories, and other mechanical devices. Thus, global warming is the concern that Earth's temperature will continue to rise along with the numbers of these certain gases in our atmosphere. Click on the links below to find out more about these greenhouse gases.

1. The Greenhouse Effect
2. NASA Research: Greenhouse Gases

Atmospheric Aerosols

Aerosols are the miniscule particles floating freely about the atmosphere at any given time. These can be produced from volcanic eruptions, vehicular emissions, or even wildfires. In fact, human activity accounts for 10% of the aerosols in the atmosphere. Because of our atmospheric air currents, these particles have the ability of traveling across the globe in a very short time, and remaining in the atmosphere for months on end. The computer animation below on Mt. Pinatubo's eruption in 1991 shows how dust and ash, released in one spot on the globe, can affect the entire Earth. In fact, in the months following the Mt. Pinatubo eruption, the Earth's average temperature dropped by half a degree! So, it can be seen that these aerosol particles have an overall cooling effect on our climate. When the uv radiation from the Sun enters the atmosphere, some is reflected away from the Earth's surface by these free-floating aerosols. Thus, less uv radiation actually hits the surface of the Earth. Some scientists seem to believe that the aerosols in the atmosphere could balance out the warming effects caused by the increase in greenhouse gases.

-Mt. Pinatubo animation-

1. What are Aerosols?
2. Aerosols and Climate

Intercontinental Transport

One of the main focuses of the INTEX mission will be to determine the chemical transport on intercontinental scales. Evidence has shown that chemicals from East-Asian countries have migrated over to the west coast of the United States. As seen in the Mt. Pinatubo demonstration video, our atmosphere is capable of circulating matter around the globe in extremely short periods of time. INTEX will strive to quantify this outflow of chemicals from Asia to the United States, as well as from the United States to Europe. The main concern is on those chemicals that are particulary long-lived in the atmosphere. These pose the greatest threat to long-term climate change, as they can stay airborne for longer periods of time. Find out more from the links below.

1. NOAA Intercontinental Transport
2. Transport of Nitrogen Oxide Pollution