[Coral-List] CRW Reduces Outlook for Thermal Stress Potential in the Caribbean in 2009
Mark Eakin
Mark.Eakin at noaa.gov
Tue Sep 15 17:11:23 EDT 2009
The NOAA Coral Reef Watch (CRW) Coral Bleaching Thermal Stress Outlook
indicates that the potential for coral bleaching in the Caribbean in
2009 has lessened. While there continues to be an elevated potential
for higher than normal temperatures in 2009, severe thermal stress is
less likely than earlier outlooks indicated. There is still some
potential for thermal stress that may lead to bleaching along the
Pacific coast of Mexico and islands in the equatorial central Pacific
Ocean. So far, it appears unlikely that bleaching will be severe in
those areas either.
NOAA’s operational Climate Forecast System continues to call for El
Niño development during 2009-10. If El Niño conditions continue to
strengthen, this could increase the bleaching risk in the central to
eastern Pacific and Caribbean late this year and next year. Remember
that this guidance should be used as an indicator of potential general
patterns rather than a precise predictor of thermal stress at any
location.
The full message with images can be found at: http://coralreefwatch.noaa.gov/satellite/bleachingoutlook/outlook_messages/bleachingoutlook_20090915_for_2009sepdec.html
Caribbean and Eastern Pacific Bleaching Outlook:
Temperatures across the Caribbean have continued to be
warmer than normal during 2009 and have continued to rise in many
areas. However, in most parts of the basin we have not seen
accumulation of thermal stress at levels that causes significant
bleaching. The current forecast model indicates that slightly
elevated temperatures are likely to continue across the Caribbean
basin through the end of the 2009 bleaching season. This is a marked
improvement from concerns of prolonged high temperatures that were
prompted by the models earlier in the year. Thermal stress may reach
levels high enough to cause some bleaching, especially in the Lesser
Antilles and the Caribbean coast of Central America. While significant
accumulation of thermal stress is no longer expected, some areas still
may be at some risk of bleaching.
NOAA’s operational Climate Forecast System and other meteorological
agencies continue to call for development of El Niño conditions during
2009-10. Typically this has the strongest impact in the Caribbean
during the second year of the El Niño (2010). With the developing El
Niño, temperatures may continue to increase in the eastern Pacific
Ocean off Mexico, posing a concern for some bleaching of coral reefs
along that coast.
Pacific Bleaching Outlook:
While there is still some indication that higher than
normal temperatures may continue in the central equatorial Pacific
from Kiribati to the Marshall Islands, the threat of significant
accumulation of thermal stress has abated there as well. This region
is also subject to intensification during El Niño conditions, so El
Niño forecasts should be monitored in the coming months as any
strengthening or weakening of the El Niño may change the potential for
bleaching.
Current Bleaching Conditions:
Temperatures continue to be above normal and are rising in most of the
Caribbean, but temperatures and thermal stress accumulation are not as
high as those seen in August 2005, particularly around Puerto Rico and
the Lesser Antilles. Only a few localized areas have experienced
significant accumulation of thermal stress – of particular note are
prolonged high temperatures in Florida Bay. Recently, the Caribbean
Mexican and Belizean coasts of Central America, southern Cuba, Cayman
Islands, and Jamaica have experienced the highest water temperatures
of this decade and need to be closely monitored during the next month.
Note: high thermal stress levels in the Gulf of Panama are the result
of a known error in the climatology used for our products. CRW’s
current HotSpot and DHW data should be disregarded in the Gulf of
Panama until we release our new, Enhanced-50km version of the CRW
products later this year.
Temperatures across much of the Pacific are above normal, consistent
with El Niño development. However, the Pacific coast of Mexico is the
only reef-bearing area that has experienced significant accumulation
of thermal stress.
About the Outlook System:
The Thermal Stress Outlook is based on sea surface temperature (SST)
forecasts generated by the Linear Inverse Model (LIM) from the NOAA
Earth System Research Laboratory. In a normal year, the Outlook
forecasts no potential for bleaching. When forecast SST exceeds
bleaching thresholds over a long enough period to cause bleaching, the
outlook maps display the bleaching potential. Actual conditions may
vary due to model uncertainty, subsequent changes in climatic
conditions, extreme localized variability, or weather patterns. Two
updates of the bleaching outlook system are currently being developed.
The first will be a minor adjustment to the system now in use. The
second will develop an entirely new outlook system that uses the
operational Climate Forecast System (CFS) of the NOAA National Centers
for Environmental Prediction in the way we now use the LIM model. We
hope that the CFS-based version will be available for the 2010
northern-hemisphere bleaching season and can be used to compare
against the updated LIM-based system.
Our seasonal bleaching outlooks can be found at:
http://coralreefwatch.noaa.gov/satellite/bleachingoutlook/index.html
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
Cheers,
Mark
------------------------------------------------------------------------------------------------
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
301-502-8608 mobile
"This is the generation that must also stop the spread of the
pollution that is slowly killing our planet, from shrinking coastlines
and devastating storms to widespread misery and famine and drought.
The effects of climate change are now in plain sight."
Barack Obama, Apr. 3 2009
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