GOES Captures Last Month's Tornado Activity in the US Southeast

Well not exactly. GOES (Geostationary Operational Environmental Satellite) captured the storm systems which generated the series of tornadoes which ravaged the deep south of the US. The movie, linked here, shows a time-lapse of the weather systems that occurred in April along with red points indicating where tornadoes were detected by ground stations and observers. One can see that some of the storm systems stall over the midwest generating a series of tornadoes there, where as other systems sweep across the country spawning tornadoes on their way.

So what is GOES anyways? GOES is a series of satellites run by NOAA's National Weather Service (National Oceanic and Atmospheric Administration). There are 3 active GOES satellites. Each of them sit in geosynchronous orbit. These type of orbits are special, originally proposed by Arthur C. Clarke, in that the amount of time it takes to complete the orbit is the same as the amount of time it takes the Earth to rotate. Thus a satellite in this orbit, at a radius of about 42,000 km, appear to hover over the same region on the Earth. This makes it an ideal location for communications and weather satellites. The 3 active satellites in GOES watch three different regions of the western hemisphere. The three active satellites are dubbed GOES-West, which watches the western US and Pacific Ocean, GOES-East which watches the eastern US and Atlantic and GOES-South which covers South America.

The GOES satellites have a variety of instruments to measure weather phenomenon on Earth. They have visible light camera's to measure the reflected sunlight from the Earth, infrared cameras to see the heat emitting from the Earth, and sounding sensors which provide information about the atmospheric temperature, moisture and ozone levels. In addition GOES monitors the magnetic field and energetic particle environment in its orbit as well as monitoring the Sun.

With it's ability to provide a global images of current weather, GOES is an indispensable part of weather forecasting in both the US and Canada. Given how important GOES is for this there are always backup GOES satellites in orbit to take over in case one fails. Thus far, since 1975 there has been 15 GOES launched into orbit. Currently GOES 11-13 are active with 1-10 having been decommissioned or turned to alternate uses (GOES 3 serves as a communications relay for the research station at the South Pole) . GOES 14 and 15 are the two backup satellites with newer models set to be launched in 2015. Thus GOES will be the premier general purpose weather satellites for years to come.