[Coral-List] Fwd: HotSpot myth and history

Thomas Goreau goreau at bestweb.net
Thu Oct 19 16:09:30 EDT 2006


> From: Thomas Goreau <goreau at bestweb.net>
> Date: October 5, 2006 9:22:46 PM EDT
> To: coral-list at coral.aoml.noaa.gov
> Subject: HotSpot myth and history
>
> "History" written long after the event is too often a post hoc myth  
> or justification of later events by those in a position to write  
> their version of the "facts".
>
> It is just NOT at all correct to say (posting below) that:
>
>  "The data from which Tom and colleagues developed the original
>> ?hotspots? were, in essence, blended products that used some
>> satellite data but mostly in situ data to construct hand-drawn
>> monthly fields"
>
> although it is truly touching to see what is, as far as I know, the  
> first acknowledgment of where the method originally came from.
>
> From the very start of our development of the HotSpot method we  
> used purely satellite databases because of their wide coverage and  
> internal consistency compared to in-situ data, but we first  
> carefully calibrated several different NOAA satellite databases  
> which had very different effective resolution (most people using  
> the satellite data maps are not aware that the processing  
> algorithms can smooth out the data on some of those pretty color  
> maps over up to hundreds of kilometers) against years of our own in- 
> situ data, showing that the highest resolution satellite databases  
> were within a few tenths of a degree of the true value but  
> generally underestimated it to an increasing degree at higher  
> temperatures, the likely reasons for which are explained in our  
> papers.
>
> Naturally, since we were working with no funding at all, those with  
> millions to spend could make prettier color maps faster, but the  
> fact remains that our original HotSpot method works essentially  
> just as well as any of the fancier and much more expensive later  
> versions, since the other effects on bleaching that people searched  
> intently for in order to downplay the significance of high  
> temperature are generally minor compared to the temperature effects  
> per se (as was long known to at least three generations of coral  
> biologists). Al Strong certainly deserves credit for making very  
> significant contributions by using night time temperatures and  
> automating the database, but one can't help feeling that the  
> progress would have been much more rapid had basic coral biology  
> and the originators of the method not been totally cut out of the  
> method's subsequent development.
>
> Now if they would only come out of the closet and admit that rising  
> temperatures and bleaching are due to global  
> heating....................
>
> Tom
>
> Thomas J. Goreau, PhD
> President
> Global Coral Reef Alliance
> 37 Pleasant Street, Cambridge MA 02139
> 617-864-4226
> goreau at bestweb.net
> http://www.globalcoral.org
>
>> Date: Wed, 04 Oct 2006 14:26:59 -0400
>> From: Mark Eakin <Mark.Eakin at noaa.gov>
>> Subject: [Coral-List] The Evolution of HotSpots
>> To: Coral Listserver <coral-list at coral.aoml.noaa.gov>
>> Message-ID: <1BB21B76-66C3-4D88-A62F-D9B097E06206 at noaa.gov>
>> Content-Type: text/plain;	charset=WINDOWS-1252;	delsp=yes;
>> 	format=flowed
>>
>> In a recent posting, Tom Goreau raised the issue that the NOAA coral
>> bleaching HotSpots are a short-term measure and differs from the
>> concept as he originally conceived.  He is correct that our products
>> have evolved through time and are no longer the same as the ?hotspot?
>> concept that he published with colleagues over a decade ago.  As Tom
>> notes the early ?hotspot? product was developed as an analysis of the
>> monthly SST products that were available at the time.
>>
>> The data from which Tom and colleagues developed the original
>> ?hotspots? were, in essence, blended products that used some
>> satellite data but mostly in situ data to construct hand-drawn
>> monthly fields.  This analysis was not available until some weeks
>> after a month had concluded and used input data that varied from
>> month to month.  As satellite data availability improved and Al
>> Strong worked with Tom, students from the US Naval Academy, and other
>> colleagues, a new set of products evolved.  These were based on daily
>> satellite data of known quality and origin and were available much
>> more rapidly than the old monthly data fields.  The NOAA HotSpot data
>> developed as twice-weekly products (see Strong et al. 1997 and its
>> references to the development from the original Goreau approach) that
>> provided 3 and 4 day average anomalies above the maximum monthly mean
>> in a timely manner.  It was only then that the product moved from
>> being an interesting scientific product that was useful in
>> understanding bleaching events in hindsight, to a product that
>> scientists and managers could use to understand events that were
>> taking place on their reefs in near-real-time.
>>
>> However, the short-term nature of the NOAA HotSpot product left a
>> need to understand the thermal stress in a way that captured both the
>> long-term accumulation of stress and delivered a product in near- 
>> real-
>> time.  This led to the birth of the Degree Heating Weeks, an
>> accumulation of NOAA HotSpots over 12 weeks.  This product has been
>> almost 100% successful in identifying conditions that result in
>> bleaching.  It is a bit conservative, as some bleaching events occur
>> below the Bleaching Alert Level 1 (4-8 Degree Heating Weeks).
>> However, except for problems that we have recently identified in the
>> climatology near Oman, all of our distributed reports of stress that
>> should lead to bleaching (Alert Level 1 or higher) have been verified
>> by field observations.  Our Bleaching Watches and Bleaching Warnings
>> are indications that water temperatures have reached threshold levels
>> and that there is a need to be on the lookout for bleaching in the
>> field.
>>
>> In the late 1990s, NOAA saw the need for a near-real-time monitoring
>> product that could alert managers and scientists of the potential of
>> bleaching.  NOAA's Coral Reef Watch is a vital program that works to
>> deliver those needed products.  We stand behind the need for such a
>> product suite and continue to work with reef managers to develop new
>> products to improve our services.
>>
>> By looking at our methodology page, our publications, and their
>> references, one can find trace the evolution of the product from
>> Tom's original construct to the product suite that we now provide.
>> The field has probably matured enough that it is time to write a
>> retrospective article on the history and evolution from Tom's
>> ?hotspots? to the NOAA HotSpot and NOAA Degree Heating Week products
>> and our future directions.
>>
>> 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
>
>
>

Thomas J. Goreau, PhD
President
Global Coral Reef Alliance
37 Pleasant Street, Cambridge MA 02139
617-864-4226
goreau at bestweb.net
http://www.globalcoral.org




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