NASA Satellite Flies High to Monitor Sun's Influence on Ozone

In October, the Upper Atmosphere Research Satellite (UARS) completed the first measurement of the solar ultraviolet radiation spectrum over the duration of an 11 year solar cycle, a period marked by cyclical shifts in the Sun's activity. This long measurement record by two instruments aboard UARS will give researchers better insight into how fluctuations in the Sun's energy affect ozone and the Earth's climate. In turn, the dataset gives scientists tools to document the influence of man-made chemicals on ozone loss.

Though mission success was initially declared only 18 months after its launch in September 1991, UARS has continued to track ozone levels and atmospheric gases that react with ozone. The satellite has now also recorded the Sun's influence on ozone and other gases over an entire solar cycle.

During the 11-year solar cycle the Sun undergoes periodic changes in activity from the "solar maximum," to a period of quiet called the "solar minimum." During the solar maximum there are many sunspots, solar flares, and coronal mass ejections, which can affect communications and the atmosphere here on Earth.

"Having a complete solar cycle of data provides information necessary to distinguish the natural variations in the Earth's atmosphere from man-made variations," said Charles Jackman, UARS Project Scientist at Goddard.

For the complete article on the UARS mission, go to: http://www.gsfc.nasa.gov/topstory/2002/1114uars.html