We should all thank AP’s Seth Borenstein for this, IMHO. Without his article on July SST’s being the hottest ever and it not making much sense, people such as Dr. Spencer may not have been immediately motivated to figure out what was going on with the SST’s. – Anthony
—
Spurious Warming in New NOAA Ocean Temperature Product: The Smoking Gun
Dr. Roy Spencer August 27th, 2009
After crunching data this week from two of our satellite-based microwave sensors, and from NOAA’s official sea surface temperature (SST) product ERSST v3b, I think the evidence is pretty clear:
The ERSST v3b product has a spurious warming since 1998 of about 0.2 deg. C, most of which occurred as a jump in 2001.
The following three panels tell the story. In the first panel I’ve plotted the TRMM Microwave Imager (TMI) SST anomalies (blue) for the latitude band 40N to 40S. I’ve also plotted SST anomalies from the more recently launched AMSR-E instrument (red), computed over the same latitude band, to show that they are nearly identical. (These SST retrievals do not have any time-dependent adjustments based upon buoy data). The orange curve is anomalies for the entire global (ice-free) oceans, which shows there is little difference with the more restricted latitude band.
In the second panel above I’ve added the NOAA ERSST v3b SST anomalies (magenta), calculated over the same latitude band (40N to 40S) and time period as is available from TRMM.
The third panel above shows the difference [ERSST minus TMI], which reveals an abrupt shift in 2001. The reason why I trust the microwave SST is shown in the following plot, where validation statistics are displayed for match-ups between satellite measurements and moored buoy SST measurements. The horizontal green line is a regression fit to the data. (An average seasonal cycle, and 0.15 deg. C cool skin bias have been removed from these data…neither affects the trend, however.)
I also checked the TMI wind speed retrievals, and there is no evidence of anything unusual happening during 2001. I have no idea how such a large warm bias could have entered into the ERSST dataset, but I’d say the evidence is pretty clear that one exists.
Finally, the 0.15 to 0.20 deg. C warm bias in the NOAA SST product makes it virtually certain that July 2009 was not, as NOAA reported, a record high for global sea surface temperatures.
UPDATE: Dr. Spencer has an update to this post here:
http://wattsupwiththat.com/2009/08/31/spencer-always-question-your-results/
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Walter Dnes (22:41:22) :
Am I correct with the following extrapolations?
* Both Hadley and GISS monthly anomalies are the average of the global SST anomaly and global land anomaly
* If SST is 0.15 to 0.20 C too high, does that mean that all Hadley and GISS monthly anomalies back to 2001 should be adjusted downwards 0.075 to 0.1? Or am I dreaming?
Can someone confirm whether Hadley and GISS is this specific product for their monthly global SST anomalies?
Re: Hadley (from web-site)
“The SST data are taken from the International Comprehensive Ocean-Atmosphere Data Set, ICOADS, from 1850 to 1997 and from the NCEP-GTS from 1998 to the present. HadSST2 is produced by taking in-situ measurements of SST from ships and buoys, rejecting measurements which which fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and calculating a robust average of the resulting anomalies on a 5° by 5° degree monthly grid. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in SST measuring practices before 1942. The uncertainties due to under-sampling have been calculated for the gridded monthly data as have the uncertainties on the bias corrections following the procedures described in the paper..”
A quick look at Hadley ocean data suggests July 2009 not as warm as July 1998. July 1998 anomaly is ~0.04 warmer than July 2009 which looks to be reasonably consistent with TRMM TMI (first plot above). Note, though the Hadley data is global whereas TRMM data is between 40N and 40S.
Also I’m not sure how the rest of the data series matches up. Data is here:
http://hadobs.metoffice.com/hadsst2/diagnostics/global/nh+sh/monthly
Even worse:
From http://www.ncdc.noaa.gov/oa/climate/research/sst/papers/xue-etal.pdf
“Interdecadal Changes of 30-Yr SST Normals during 1871–2000″
Abstract:
At the National Oceanic and Atmospheric Administration
Climate Prediction Center (CPC), the official forecast
for the tropical Pacific sea surface temperature (SST) index
is issued as anomalies and standardized anomalies relative
to a 30-yr normal: climatological mean (CM) and standard
deviation (SD). The World Meteorological Organization
(WMO) suggests that the 30-yr normal be based on a 30-
yr base period that starts at the beginning of each decade
(1951–80, 1961–90, etc.). Although the WMO did not
specify the periods on which SD is based, the same base
periods are used at CPC for both CM and SD. For a
historical reason, the CM originally used at CPC is that
calculated for the 1950–79 base period (Reynolds and
Smith 1995). To comply with the WMO’s standards, the
1961–90 base period was introduced at CPC around 1997
(Smith and Reynolds 1998). In early 2001, CPC was requested
to implement the 1971–2000 normal for operational forecasts.
So, we constructed a new SST normal for the 1971–2000 base period and implemented it operationally at CPC in August of 2001”
A new base period was introduced 1997-1998 and then we got all time high anomalies in 1998.
Coincident? I dont think so….
Then they constructed a new SST normal in 2001 that seems to be “trimmed” to fit this heat. And of course will the reality not fit the model.
Lucy
I have posted many times here on satellite measurements of sea levels.
Historic IPCC tide gauge data is based on three North European sites to 1700 (the data doesnt actually exist but has been interpolated)
To this has been spliced satellite data which has numerous problems and whose error of measurement is greater than the measurement itself.
We should realise that global sea level data is even more flawed than global land temperatures-and that is saying something
Bristol Channel sea rise is negligible and arguably has been falling for three years. To reach the predicted rise of 1 metre by the end of the century UK rise has to speed up by 650% this year and remain at that level for the rest of the century.
If you want the various items I have posted here I can email them to you
Tonyb
I haven’t been frequenting much lately, so apologies if you’ve already seen this. Nir Shaviv has a nice post up on ocean heat content:
http://sciencebits.com/calorimeter
With the shift found by Dr. Spencer and the improper siting found by Anthony, it seems to me the increase in global temperatures over the last century or so can be mostly explained as instrument error or rather a bias applied to the instruments and not a real trend.
Since most of the hot seas were around the poles in July 09, I do not see how something weird (if ever) in the 40/40 average temperature could disqualify the global record. It only could mean something for the tropics, say.
I would really be curious to see how the mentioned “spurious” error looks like at the global scale?
REPLY: The seas aren’t “hot” at those locations. Wrong word, wrong thinking, wrong way Flanagan. If you think they are “hot” I suggest you go there, spend a few minutes in the water, and report back.
Bob H. (06:27:28) : “With the shift found by Dr. Spencer and the improper siting found by Anthony, it seems to me the increase in global temperatures over the last century or so can be mostly explained as instrument error or rather a bias applied to the instruments and not a real trend.”
Add to these proofs that of E.M. Smith as he goes carefully (with bleary eyes, but a citizens dedication) through the computer code. He is finding a number of “fixes”. Read his posts from at least August 13 on GISSTemp.
http://chiefio.wordpress.com/2009/08/13/gistemp-quartiles-of-age-bolus-of-heat/
My deep gratitude to all those who are exposing the charade (a kind word) designed imo to severely hobble the developed world. Also see E.M. Smith’s posts re we are not running out of energy/stuff. Think affluence. Anthony’s WUWT offers old-fashioned values of abundance, inventiveness, and resourcefulness
@Reply – obviously Flanagan was talking about anomalies, which are +5° C or over in the (sub-)Arctic. In a sense that is ‘hot’.
If Flanagan’s thinking and ‘way’ are wrong, I guess calculation of the global average SST from the 44% of the earth that lies between 40° NL en 40° SL is scientifically sound and convincing?
REPLY: Oh puhleeze. Spencer did that to look for something to explain the step function. if there was an event, it would show up in both data sets, though likely less impact due to less area. He used what was available, if you can do better, I welcome you to present it here as a guest post.. – Anthony
I think the individual components of the ERSSTv3b dataset need to be reviewed.
There is a big difference between the in-situ ship-based measurements and the bouy-based measurements.
If the bouys do not show much difference and there is no particular significant change in how ships took SST measurements around 2001, there could be some other artifact in the processing or the algorithm for the ship-based measurements.
The NOAA also produces this comparison of how the SST map looks under the different versions – I don’t see enough of a difference to explain the discrepency in the recorded monthly number.
ftp://eclipse.ncdc.noaa.gov/pub/ersstv3b/maps/ersst4-200907.gif
@Walter Dnes
What I was talking about in my previous post was that, to the best of my knowledge, Hadley and GISS compute monthly global anomalies as 50% land and 50% sea.
If correct I wonder how they can justify that basis.
Those with power want only one thing: more power.
And those with power must be kept in check.
We are the checks and balances of the Climate Change movement.
We don’t deny that C02 has a warming effect. But we are naturally skeptical of impending doom and emotional manipulation of the masses from its associated hysteria.
RR, check your math. You’ll find that 64% of the planet’s surface lies between 40 NL and 40 SL. The % of the oceans in those latitudes is probably even slightly higher given the distribution of the continents!
Flanagan: You wrote, “Since most of the hot seas were around the poles in July 09…”
Really?????
Please identify the SST dataset you are referring to. The NCDC’s OI.v2 SST shows reductions in Southern Ocean SST anomalies over the past few years.
http://i29.tinypic.com/9ubsec.png
Same thing with the Arctic Ocean:
http://i31.tinypic.com/nv8l8k.png
RR: You wrote, “@Reply – obviously Flanagan was talking about anomalies, which are +5° C or over in the (sub-)Arctic. In a sense that is ‘hot’.”
Please identify that dataset that you are refering to. A link would do.
Thanks
Walter Dnes (22:41:22) :
“Am I correct with the following extrapolations?
(…)
* If SST is 0.15 to 0.20 C too high, does that mean that all Hadley and GISS monthly anomalies back to 2001 should be adjusted downwards 0.075 to 0.1? Or am I dreaming? ”
The following panel shows the anomalies of GISS, Hadcrut3, RSS and UAH from 2000 to 2003. I had the opinion that a warm bias could be found in the data of GISS and Hadcrut3 if they used the ERSST dataset (of which i am absolutely not certain).
http://www.woodfortrees.org/plot/uah/from:2001/to:2003/plot/rss/from:2001/to:2003/plot/gistemp/from:2001/to:2003/plot/uah/from:2001/to:2003/trend/plot/rss/from:2001/to:2003/trend/plot/gistemp/from:2001/to:2003/trend/plot/hadcrut3gl/from:2001/to:2003/plot/hadcrut3gl/from:2001/to:2003/trend
I tentatively conclude:
– there is no lasting warm bias in the data of GISS and Hadcrut since 2001 due to the ERSST dataset;
– during the three first months of 2002, we find high values in the data of GISS (0.71, 0.70, 0.85) and in the data of Hadcrut (0.60, 0.61, 0.61). This values have no equivalent of that size in the RSS and UAH anomalies. I don’t know what the reason is of this.
So i think it is premature to conclude that we have to adjust downwards the GISS and Hadcrut anomalies because of the detection of Dr. Roy Spencer.
It remains true that this failure in the ERSST dataset will have far-reaching consequences. Why did NOAA not draw our attention to their drastic surgery in 2001? Which climatic data sets are reliable?
A very inconvenient situation for all AGW supporters…
RR
40°N to 40°S is a lot more than 44% of the Earth. Go back and do the math. Or do you think that 80-90N is 10% of the northern hemisphere?
Flanagan
While a difference in data near the poles would explain a difference in the July 2009 values, the article is about a discrete change that appeared in mid-2001. Are you suggesting that there’s a real and consistent difference in the anomalies poleward of 40° compared to 40°N to 40°S since 2001? I’d expect the polar oceans to be consistently close to 0° C with ice melt limiting any trends.
RR (08:14:11) :
“@Reply – obviously Flanagan was talking about anomalies, which are +5° C or over in the (sub-)Arctic. In a sense that is ‘hot’.
If Flanagan’s thinking and ‘way’ are wrong, I guess calculation of the global average SST from the 44% of the earth that lies between 40° NL en 40° SL is scientifically sound and convincing?”
Really? SST anomalies in the arctic/sub-arctic were +5° C or more in July 2009?
44% of the earth’s surface lies between 40S-40N? Are you sure?
Are you saying that the area of the earth that lies between 40-90 N and S are more scientifically significant when calculating global average SST?
Care to share where you get your science from, RR?
If Flanagan’s thinking and ‘way’ are wrong, I guess calculation of the global average SST from the 44% of the earth that lies between 40° NL en 40° SL is scientifically sound and convincing?
Quibble: it’s not 44%. It’s just 44% of the linear distance. Since the radius is largest at lower latitudes, it winds up being about 64% of the surface area.
Not talking about land surface, here. I don’t have a way to compute that. I assume that you got 44% because you took 4/9 of the distance.
RR (03:09:55) “The article obviously had to leave 56% of the earth’s surface out in order to meet the title”
RR (08:14:11) “I guess calculation of the global average SST from the 44% of the earth that lies between 40° NL en 40° SL is scientifically sound and convincing?”
–
RR, please show us your calculations.
I’m very curious to see how you are getting 56% & 44%.
Be sure to state any assumptions.
(…for example, if you are assuming Earth is flat – or something like that)
RR (08:14:11) :
“I guess calculation of the global average SST from the 44% of the earth that lies between 40° NL en 40° SL is scientifically sound and convincing?”
I think you should check your math. Area is much smaller near the poles. Quick calculation reveals that +-40 degrees is about 64% of the surface area.
Flanagan and R.R.: I believe I found your reference.
Juraj V: You wrote and attached a link. “NOAA SST do show more warm than cold basins around Arctic in July 2009:
http://www.osdpd.noaa.gov/ml/ocean/sst/anomaly.html (click July – Full Global)”
Now go and click “July – Full Global” for 2008, 2007, 2006, and 2005. The warm spots are there every July. You’re misinterpreting a seasonal component of the SST anomaly data. The seasonal variations in SST anomalies are visible in the following animation.
Note how the warm anomalies “cycle” into the Northern high latitudes during June, July, and August, but then shift down to the Southern high latitudes during the months of December, January, and February. It happens every year.
Also, the area of elevated Arctic SST anomalies increased after the 1997/98 El Nino as polar ice melted, so this adds to the illusion.
In short, you can’t look at a map for a given period of time and determine if SST anomalies are rising or falling. You have to plot the data in a graph as Dr. Spencer has done. Refer to:
http://bobtisdale.blogspot.com/2009/08/july-2009-sst-anomaly-update.html
Note the SST anomalies of the Arctic and Southern Oceans in the linked data. They are not elevated for July 2009. In fact, SST anomalies for those two datasets are declining. But you can’t see that in a snapshot in time.
I also wrote a post comparing the NOAA NESDIS and NOAA OI.v2 maps of SST anomalies in the following post:
http://bobtisdale.blogspot.com/2009/03/barents-sea-hotspot-isnt-so-hot.html
It does not appear that the NESDIS satellite data at high latitudes is supplemented and “corrected” with buoy and ship data.
If you doubt anything I’ve written in this comment, I suggest you download the data and create graphs and maps with it. You’ll then have to upload those graphs and maps to a picture-sharing website and provide a link so that we all can share in your findings.
Regards
Come to think of it, what difference does 5 degrees at 233K make to the radiation imbalance, compared with 5 degrees at 313K?
Anthony I am currently arguing with an RR type on another board. He’s implying the same thing that RR did. the Fact is when you look at the NOAA’s Numbers for 40s to 40n the Satellite numbers are simply lower then the NOAA’s numbers. That alone would increase that average!!!
Jason: You wrote, “Anthony I am currently arguing with an RR type on another board. He’s implying the same thing that RR did. the Fact is when you look at the NOAA’s Numbers for 40s to 40n the Satellite numbers are simply lower then the NOAA’s numbers. That alone would increase that average.”
What “numbers” is he citing? Is he looking at a map and guessing what the mean temperature is? Is he taking into account that Spencer is using a different base period for anomalies than the other dataset? Has he plotted the data in graphs? Does he know that the upward bias in the high latitudes of the NESDIS SST data (also known as the “Miami MCSST” dataset) was documented as far back at 1996?
What other board are you arguing at?
Regards
Bob’s post at Bob Tisdale (11:02:09) very strongly highlights the problem with the assumption of cyclostationarity in anomaly time series.
This further underscores the need to have access to & work with RAW data. Anomalies can be very useful, but since individual anomalies are functions of functions of functions, there are layers of things that must be consciously taken into account in attempts to draw sensible conclusions based on them.
–
As for 40N-40S:
Dr. Spencer controlled for that. (Review his post.)
The important thing to focus is on is why the series would diverge for any band.
Dr. Spencer did NOT maliciously choose the band. On the contrary, he worked with what was available. His results apply to 40N-40S. It would be interesting to run the comparison for other latitude bands, but we are limited to available records.
I will suggest that criticism should be fair.
Fair criticism can be constructive.