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.

On the Web:

* NOAA
http://www.noaa.gov

* NOAA Satellites and Information
http://www.nesdis.noaa.gov

* Degree Heating Week
http://www.osdpd.noaa.gov/PSB/EPS/SST/dhw_retro.html

* NOAA’s Coral Reef
http://www.coralreef.noaa.gov/