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The Earth's Breath
Understanding the troposphere starts with understanding that right now, you're in it.

You live, work and breathe in that small section of the atmosphere between the Earth's surface and 5 miles above it. Things that happen in the troposphere directly affect your day-to-day life.

A full map of the Global Tropospheric Experiment's missions. In 1984, the National Academy of Sciences decided this part of the atmosphere needed to be studied in detail, so we could make intelligent decisions to protect it in the future. NASA's response to this initiative was the formation of the Tropospheric Chemistry Program at NASA Headquarters in Washington, DC.

Click the image for a full global map of the Global Tropospheric Experiment's missions. GTE conducted over a dozen individual studies over geographic areas during almost 30 years of work.

One of the key projects of this program was the Global Tropospheric Experiment, or GTE, an aircraft-based study that monitored atmospheric changes around the world. GTE examined the causes and effects of global pollution on the air that we breathe and was based at the Langley Research Center in Hampton, Va.

Under GTE, atmospheric scientists from across the country conducted over a dozen intensive research missions around the globe. Mission locations ranged from the western coast of Greenland, to the South Pacific.

The first few hundred meters above the Earth's surface - the heart of interaction between humans and the troposphere - was the subject of the Atmospheric Boundary Layer Experiments, or ABLE. NASA's Electra aircraft, a Lockheed propeller plane designed in the 1950s, took readings of chemical processes above the tropical Atlantic, the Brazilian rainforest and the western coast of Greenland. One of the most dramatic discoveries of these missions was evidence of dust from the Sahara Desert drifting thousands of miles across the Atlantic Ocean, and settling in the Caribbean.

NASA's DC-8 research aircraft in flight.NASA's DC-8 has flown research missions for the Agency at all corners of the globe, from Ireland to Fiji. A 30,000-lb. payload capacity and ability to fly 5,000 miles without refueling make it a versatile tool for NASA's science teams.

The most recent campaign, Transport and Chemical Evolution over the Pacific, or TRACE-P, was a unique opportunity to look at the effects of Asia's industrial revolution on the atmosphere. Asia's chemical output into the troposphere has increased dramatically over the last decade, and TRACE-P was designed to use NASA's research aircraft capabilities to find out exactly what was happening as those effects drifted out over the Pacific Ocean.

Among the aircraft used for TRACE-P were NASA's DC-8, a four-engine jet that reaches altitudes of over 40,000 feet, and the P-3B, a turboprop aircraft operated by NASA's Wallops Island Facility in Virginia. Operating from Japan and Hong Kong, the aircraft collected comprehensive data on the effects of greenhouse gases, aerosols and other pollutants on the atmosphere over the Pacific.

Because of the success of the TRACE-P mission, NASA's DC-8 and additional aircraft are being planned for use in an upcoming mission to study similar chemical effects above North America. That mission is known as the Intercontinental Chemical Transport Experiment - North America (INTEX-NA), organized and conducted by NASA's Tropospheric Chemistry Program. The first phase of INTEX-NA will take place this summer.

To learn more about the historical contributions made through NASA's Global Tropospheric Experiment, visit

For additional information on INTEX-NA, visit
NASA's John F. Kennedy Space Center and Langley Research Center