NOAA 2003-020
Contact: Patricia Viets
NOAA News Releases 2003
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Scientists at the Commerce Department’s National Oceanic and Atmospheric Administration (NOAA) are using satellite data to monitor the long-term effects of heat stresses on several coral reefs throughout the world.

While the scientists have been monitoring the stresses for some time, NOAA’s National Environmental Satellite, Data, and Information Service is now providing an operational product called “Degree Heating Week”.

“Degree Heating Weeks (DHW) have been available experimentally for some time,” said Dr. Alan Strong, coordinator of Coral Reef Watch at NOAA Satellites and Information. “Turning operational means that coral reef managers and stake holders will now have up-to-date, accurate, and reliable information on the status of their reefs and may be able to take active measures to prevent further damage if their site has a high DHW rating.”

Using satellite-derived information, DHW’s continuously monitor the cumulative thermal stress of several coral reefs throughout the globe, including Australia’s Great Barrier Reef, Galapagos, the Bahamas, and others. The extent and acuteness of thermal stress, key predictors of coral bleaching, contribute to coral reef degradation worldwide.

Coral reefs compose a large and integral part of the coastal ocean, supporting a variety of sea life and providing resources of significant economic importance. Coral bleaching occurs as coral tissue expels zooxanthellae, a symbiotic algae essential to coral survival that resides within the structure of the coral. Bleaching is induced by high water temperatures.

A Degree Heating Week is designed to indicate the accumulated stress experienced by coral reefs. For example, if the current temperature of a reef site exceeds the maximum expected summertime temperature by one degree Celsius, then the site receives a rating of 1 DHW. If the current temperature at the site is two degrees Celsius above the maximum expected summertime temperature or one degree above for a period of two weeks, the site would receive a rating of 2 DHWs, and so on.

With the operational product, NOAA Satellites and Information will provide continuous technical support on a 24-hour, seven-day basis, and will maintain a Web site which will be updated twice a week.

NOAA Satellites and Information is the nation’s primary source of space-based meteorological and climate data. NOAA Satellites and Information operates the nation's environmental satellites, which are used for weather and ocean observation and forecasting, climate monitoring and other environmental applications. Applications include sea-surface temperature, fire detection, ozone monitoring.

NOAA Satellites and Information also operates three data centers, which house global data bases in climatology, oceanography, solid earth geophysics, marine geology and geophysics, solar-terrestrial physics, and paleoclimatology.

The Commerce Department’s National Oceanic and Atmosphere Administration (NOAA) is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of our nation’s coastal and marine resources.

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Degree Heating Week: