[Coral-List] Potential for High Thermal Stress in the Caribbean

Mark Eakin Mark.Eakin at noaa.gov
Fri Jul 17 09:14:16 EDT 2009

The full message with images can be found at:


The NOAA Coral Reef Watch (CRW) Coral Bleaching Thermal Stress Outlook  
indicates that there is a significant potential for coral bleaching in  
the Caribbean in 2009, especially in the Lesser Antilles. Based on our  
current model, there is a potential for higher thermal stress than  
normal in 2009.

Other areas of concern in 2009 are central Pacific including the  
equatorial Line Islands and Kiribati. Some thermal stress may also  
develop between the Northern Marianas Islands and Japan. An important  
caveat is that the model used for this outlook is not yet calling for  
El Niño development, whereas NOAA’s operational Climate Forecast  
System is now calling for development of an El Niño during 2009-10. If  
El Niño conditions continue to strengthen, this could increase the  
bleaching risk in the central to eastern Pacific and Caribbean.  
Remember that this guidance should be used as indicators potential  
general patterns rather than precise predictors of thermal stress.

Caribbean Bleaching Outlook:

             The forecast system indicates that there is a potential  
for bleaching across the Caribbean basin in 2009. At this time, the  
model indicates that there is potential for high thermal stress in  
2009 through October. Our concern at this time is that thermal stress  
potential based on the LIM model is reminiscent of that seen in July  
2005 hindcasts of the record-setting 2005 event. Currently there  
appears to be some potential for high stress in the central Gulf of  
Mexico and a region stretching from the Lesser Antilles across to the  
southern coast of Hispaniola and the Caribbean coast of Nicaragua.  
NOAA’s operational Climate Forecast System is now calling for  
development of an El Niño during 2009-10. Typically this has the  
strongest impact in the Caribbean during the second year of the El  
Niño (2010). Finally, in light of predictions for a potential of lower  
than normal precipitation in much of the Caribbean this year (see  
International Research Institute for Climate and Society and Caribbean  
Institute for Meteorology and Hydrology outlooks), we do not expect  
cloud cover to provide relief from the predicted warming as was seen  
earlier this year in Australia. We are still 2-3 months away from the  
peak of this year’s warmest months and we recommend that you monitor  
these updates as we get closer to the event.

Pacific Bleaching Outlook:

             Another area of concern in 2009 is the central Pacific  
including the equatorial Line Islands and Kiribati. This area is  
especially subject to stress if El Niño development continues. NOAA’s  
operational Climate Forecast System is now calling for development of  
an El Niño during 2009-10. There also is a potential for some thermal  
stress to develop between the Northern Marianas Islands and Japan.  
There is also some indication of thermal stress along the Pacific  
coast of Mexico. However, the model is only generating small areas in  
the Pacific with a potential for abnormally high temperatures. Care  
should be taken that these are likely to move from their current  
locations. This region is also subject to intensification during El  
Niño conditions.

Current Bleaching Conditions:

Thermal stress is still low in the Caribbean. However, early  
intensification of heating has occurred in the Gulf of Mexico and  
around the Florida Keys. In fact, the issuance of a Bleaching Watch  
for Sombrero Reef on 22 June 2009 was the earliest such alert since  
our bleaching alert system began in 2003. Two broad bands of warming  
have begun to develop across the Pacific that are consistent with El  
Niño development. This currently has warmed waters above the maximum  
monthly mean (Bleaching Watch) in the Marianas Islands, parts of  
Micronesia, and the outermost Northwestern Hawaiian Islands in one  
band, and Nauru, Howland-Baker, Kiribati, the equatorial Line Islands  
to Clipperton and Mexico along the other band.

Our seasonal bleaching outlooks can be found at:


Current HotSpot and Degree Heating Week charts and data formatted for  
HDF and Google Earth can be found at: http://coralreefwatch.noaa.gov/satellite/index.html

Time series graphics for index sites can be found at: http://coralreefwatch.noaa.gov/satellite/current/sst_series_24reefs.html

and http://coralreefwatch.noaa.gov/satellite/current/experimental_products.html

You can sign up for automated bleaching alerts at: http://coralreefwatch-satops.noaa.gov/SBA.html

Please report bleaching events (or non-events) at: http://www.reefbase.org/contribute/bleachingreport.aspx

C. Mark Eakin, Ph.D.
Coordinator, NOAA Coral Reef Watch
National Oceanic and Atmospheric Administration
Center for Satellite Applications and Research
Satellite Oceanography & Climate Division
e-mail: mark.eakin at noaa.gov
url: coralreefwatch.noaa.gov

E/RA31, SSMC1, Room 5308
1335 East West Hwy
Silver Spring, MD 20910-3226
301-713-2857 x109                   Fax: 301-713-3136

"Together, we must confront climate change by ending the world's  
dependence on fossil fuels, by tapping the power of new sources of  
energy like the wind and sun, and calling upon all nations to do their  
part. And I pledge to you that in this global effort, the United  
States is now ready to lead."
Barack Obama, Apr. 5 2009

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