NOAA satellites 'seeing' humidity
Spacecraft help forecasters predict and monitor
excessive heat
NOAA satellite imagery shows much of the United States is in the "red" this week, as a blistering heat wave tightens its grip and creeps eastward. High humidity is adding to the discomfort.
NOAA’s two satellite systems — the Geostationary Operational Environmental Satellite (GOES) and the Polar-Orbiting Environmental Satellite (POES) — are helping forecasters predict the formation, movement and the eventual end of atmospheric conditions responsible for the scorching temperatures.
Two GOES satellites, which hover in a fixed position more than 22,000 miles above the equator, are providing NOAA’s National Weather Service forecasters with constant images of the air, land and water of the Western Hemisphere. When it comes to tracking heat, GOES visible imagery identifies areas of cloud-free skies that helps speed the sun’s ability to heat the air and areas where clouds will slow down the heating process.
“Data from GOES can show where heating of the ground is occurring throughout the day, which, along with other surface based instruments the National Weather Service uses, gives an accurate picture and extent of how hot it is,” said Tom Renkevens, deputy chief of the satellite products and services division of NOAA’s Satellite and Information Service.
NOAA’s geostationary operational environmental satellite, or GOES, tracks heat waves by detecting cloud-free areas of the atmosphere that heat up quickly.
High resolution (Credit: NOAA)
POES spacecraft, which circle the globe every 102 minutes at an altitude of 517 miles above Earth, capture environmental data that are fed into sophisticated computerized weather prediction models that help NOAA forecasters “see” the early beginnings of heat waves.
For NOAA forecasters, the early detection of upper-level ridges —the long areas of pressure in the high atmosphere— is critical to heat wave warnings. A large, upper-level ridge over the center of the United States is causing the current heat wave across the country.
In general, extremely hot summers and unusually mild winters are often associated with strong, slow-moving, upper-level ridges.
“Heat kills hundreds of Americans each year – more than tornadoes, hurricanes, floods, lightning or any other weather event combined,” said Eli Jacks, chief of fire and public weather services at NOAA’s National Weather Service. “Our environmental satellites give us the ability to warn the public as early as possible, so people can prepare and stay safe.”
Data collected by NOAA’s polar-orbiting operational environmental satellite, or POES, are fed into sophisticated models that help National Weather Service forecasters “see” the early beginnings of heat waves.
High resolution (Credit: NOAA)
Visit NOAA’s Satellite and Information Service at www.nesdis.noaa.gov.
Updated July 21, 2011 