Weather Watch -- From Satellites
Weather satellites provide information essential to predicting weather. Many weather satellites are in orbit, gathering data for people to do weather- and climate-related research. The major weather satellites for the United States are called Geostationary Operational Environmental Satellites, or GOES. The GOES are owned and operated by the National Oceanic and Atmospheric Administration, or NOAA, in partnership with NASA, which manages the building and launch of the satellites. Each satellite has two major instruments on board. One instrument sends information on clouds, water vapor in the atmosphere, wind speed and direction, temperature, and even smoke from fires. The other instrument sends information on temperatures in the atmosphere, on the land, and at the surface of the oceans. It also transmits data on ozone and clouds and on water vapor in different layers of the atmosphere. The information from both of these instruments helps weather forecasters predict weather more accurately than ever before.
Several GOES satellites orbit Earth at an altitude of about 22,000 miles (36,000 kilometers). At this altitude they are in orbits that allow them to remain directly above one spot on Earth. At least two satellites are always providing weather data about the United States. GOES-East is over the equator viewing the Atlantic Ocean and eastern part of the U.S. (at 75° W longitude -- the same as Philadelphia, Pa.). GOES-West is over the equator viewing the Pacific Ocean and the western part of the U.S. (at 135° W longitude -- the same as Sitka, Alaska).