Atmosphere Observation

The observational systems described so far can be used to measure more than just physical properties such as temperature, pressure, and air movements. They can also be used to determine the chemical composition of the atmosphere. Such measurements can be valuable not only in the field of meteorology, but in other fields as well.

One of the earliest examples of such research dates to 1804 when the French physicist Joseph Louis Gay-Lussac traveled in a balloon to a height of 23,000 ft (6,900 m). At this altitude, he collected an air sample that he analyzed upon his return to the ground. Gay-Lussac found that the composition of air at 23,000 ft (6,900 m) was the same as it was at sea level.

An example of this kind of research today involves the issue of climate change. Over the past decade there has been a great deal of interest with respect to large scale changes in the Earth's climate. Many scientists believe that an accumulation of carbon dioxide and other gases in the atmosphere has been contributing to a gradual increase in the Earth's overall average annual temperature. This phenomenon is referred to as global warming. If such a change were, in fact, to occur, it would have significant effects on plant and animal (including human) life on Earth.

Many of the questions about global climate change cannot adequately be answered, however, without a fairly good understanding of the gases present in the atmosphere, changes in their concentration over time, and chemical reactions that occur among those gases. Until recently, most of those questions could not have been answered. Today, however, manned aircraft, rockets, and satellites are able to collect some of the kinds of data that will allow scientists to develop a better understanding of the chemical processes that occur in the atmosphere and the effects they may have on both weather and climate.