I’ve mentioned before how chosen color schemes greatly influence how people see surface temperature data. Frank points out that sea surface temperature presentations suffer from the same problem. – Anthony
Guest post by Frank Lansner
This is no news – but still needs to be told. NOAA can in many contexts come up with the hottest temperatures available. Here we take a look at the European Sea Surface Temperatures as of 3 may 2010.
NOAA vs. UNISYS, SST, Europe. When I look at this compare, again and again I have to check if these SST are from the very same date, 3 may 2010. But they are. Differences are immense to an extend where it hardly makes sense to look after the European SST?
NOAA is hotter than UNISYS in for example these waters:
The Baltic Sea, The North Sea, The Caspian Sea,
And in addition,
The Black Sea has NOAA Approx. 3,5 K warmer than UNISYS, and
“The NOAA hotspot area” North of Scandinavia: NOAA Approx. 4 – 6 K warmer than UNISYS .
Is there a valid sound simple explanation for these great differences?
In addition NOAA uses a colour scheme that makes Europe look as if surrounded by burning lava. It’s quite a difference to the impression you get when looking at the UNISYS graphic.
So which graphic is correct? For the Baltic, here’s what the “jury” says, SMHI (From Sweden) has an updated SST for the Baltic Sea from exactly 3 may 2010:
The 3 graphics agree reasonably for the Northern Baltic Sea, but for the rest of the Baltic Sea, SMHI shows in average around – 1,5 degrees Celsius anomaly. Both UNISYS and NOAA show too warm temperatures, but NOAA far worse than UNISYS. So, NOAA is around 2 K warmer in this area than SMHI – the best estimate.
Europe is not the only area where NOAA has warmer temperatures than UNISYS. NOAA appears markedly warmer than UNISYS on the Northern Hemisphere – but a little colder than UNISYS in areas of the Southern Hemisphere:
http://weather.unisys.com/surface/sst_anom.html
Link to NOAA SST – use “FULL GLOBAL” to see all:
http://www.osdpd.noaa.gov/PSB/EPS/SST/climo.html
Link to SMHI detailed SST for Baltic + Danish waters:
http://www.smhi.se/polarview/
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Visit Frank’s blog: Hide the decline
This is called “selling your deal” – any good presenter using a map representation of data will choose color schemes to emphasize the desired point. You may not agree with their point of view but the pro-AGW people are not stupid . The fully know what they are doing with the color schemes chosen. This technique is used all the time in the presentation of geophysical / geological data (my area of expertise). Of course, if you are used to looking at data presented in this way, you can see past the color scheme & see what the data is truly telling you. The problem is the general public does not fall into that category and can be easily mis-led by the color scheme
And you still don’t understand differing baselines.
REPLY: Rat Boy, we understand differing baselines just fine, the issue is the color presentation. -A
“Differences are immense to an extend”? Did you mean extent?
When one sees certain typos as that, one wonders if there was any scrutinizing of the claim made in the story. Just saying because anyone can write a piece these days (and they do).
P.S. Are color blind people more apt to be skeptics? Curious because I am color blind.
The usual confusion between ‘anomaly’ and ‘temperature’. If there is no confusion the the maps should not be labeled SST, but SSTa or some such, as the SMHI does. If the baselines are different, the anomalies will be different, and color scales may not mean the same thing even if red = 4 degrees for both.
Interesting.
Just looking at the color distribution shows a huge difference in presentation. NOAA uses a two-tone color scheme — hot or cold. And of course the colors chosen for hot have a much greater impact.
Now, look at the UNISYS color scheme — it’s what I call a Goldilocks scheme. The strongest colors are reserved for the extremes, greater or less than 2, while the mid-range has the more subdued colors, so that most of the water temps are “just right”. And, of course, it is far less dramatic.
As for the other differences — I’ll leave that to someone with a stronger stomach.
Completely OT–but I just watched the Discovery Channel’s special on “The Volcano That Stopped the World”. Great show–especially the passionate explanations by the geologists–until they HAD to bring AGW into the mix.
Their speculative claim: That anthropogenic global warming is increasing the likelihood of sub-glacial volcanoes (like many in Iceland) erupting–due to the melting of the glacial mass, effectively removing the ‘lid’ from such volcanoes. They call it something like ‘unloading’. They were also kind enough to blame human’s CO2 emissions.
I didn’t check to see if Al “Manbearpig” Gore was funding the show, but I can’t help but ask the obvious about this claim:
1. What proof is there that humans are definitively warming the planet? (Other than UHI)
2. What proof is there that human activity is causing the reduction in glacial ice sheets? (Reminder–we’re talking about continental-type or land-based glaciers, not sea ice here.)
3. What proof is there that–whatever the cause of the reduction–reduction in glacial mass above a volcano can serve as a ‘trigger’ for volcanoes of the Icelandic ilk?
4. Why did they have to put that shameless plug for emissions reduction into the show?
Oh–I just figured it out. We can blame the Icelandic government, which has obviously told the producers of the show that Icelandic-lava-fueled geothermal energy can be used INSTEAD of fossil-fuel based energy. Now it makes sense.
Actually, I welcome the scientific arguments supporting their claim. It is an interesting one. If it’s well-documented, then I’ll apologize with foot-in-mouth.
We experience daily changes in temperature far in excess of the anomalies shown without much discomfort. This fixation on “temperature” is quite meaningless but a handy distraction from trying to explain the physics of the atmosphere which, it appears, nobody understands.
If the physics of the atmosphere were understood we would be inundated with daily tutorials explaining how and why it WILL get warmer. Instead of tutorials we get daily threats.
I have some problem to understand what they measure the sst temperature on when i look at this two sites, ice or water ?
http://www.smhi.se/polarview/
http://www.smhi.se/oceanografi/istjanst/produkter/sstchart.pdf
Yes, the colours are used differently, but the changed are more then just use of colours.
See the black sea. For UNISYS its around -1 K or less, for NOAA its above +2 K in anomaly.
When you take your time you will see that this is more than the (very effectfull) colour use.
Joanne Nova presented me for a graphic she made for 3 may where it becomes obvious that also the whole Mediterranean appears more than 1 K to hot in the NOAA.
Leif Svalgaard: you write: “The usual confusion between ‘anomaly’ and ‘temperature’.”
UNISYS describes their plot: “Sea Surface Temperature Anomaly Plot ”
NOAA describes their plot:”SST Anomaly (degrees C)”
And then Leif, you also mention the obvious , that the colour use is different, but I would not have posted this if it was only a color use issue. Its far from that, please take your time and look more carefully.
Wrt color schemes: The NOAA color schemes strikes me as the more honest. Using light blue for anomalies up to +1 and green for up to +3 is downright deceptive. Shades of blue for all -ve and yellow/orange/red for all +ve is much more natural.
Wrt baselines: Frank L certainly gives the impression he does not understand this subtlety. I’m sure AW does, but he was remiss in not dismissing that part in his intro to the original post.
Claiming that the Baltic is warmer than normal is utterly absurd. We have just come through the coldest winter in a generation, and ice-cover in the Baltic was the worst since 1985. The last ice in the Bay of Riga and Gulf of Finland only melted about a week ago and the Gulf of Bothnia is still ice-covered, and expected to remain so for most of May. I live near the Baltic coast, and the spring is unusually late this year because of the cooling effect of the sea.
NOAA is either negligent or deliberately misleading.
Pekke: Water temperature is measured, but the anomaly map which is satellite based probably includes meltwater on top of the ice. Melting ice is always at zero degrees centigrade. Notice the positive anomaly in the northwestern gulf of Bothnia. There is a large lead there at the moment and water up there is very nearly fresh, so it is at its densest at 4 degrees centigrade. On the finnish side where there is still ice the temperature is around zero.
The color scheme fussing is silly. My own area is computational fluid dynamics, and the NOAA style scheme has been standard for at least 30 years. It’s even there as one of the standard palettes (heat.colors) offered by R, a stats package which has nothing to do with climate science.
Yes, it makes higher temperatures look hotter. It’s meant to. It communicates something to the reader.
And Leif and Rattus are right. If you’re doing these comparisons you should at least acknowledge the difference in anomaly bases.
All publications from NOAA with particulars about the climate are showing more than substantial differences with independent scientific institutes and their measurements .
Who is in charge of NOAA publications on the internet and is this a deliberate attempt to influence public opinion in order to push the AGW – cap and trade agenda ?
Situation in the USA is under Obama rule getting worse than in Russia during the recent 50 years !
Both colour schemes are poor in my opinion.
A much better way is to use white as the neutral temp anomaly (-0.5 to 0.5) then take it from their. The BOM use this for their enso sst updates and it seems to work much better.
The NOAA colour scheme is of course based on the childrens bath water temp strip. Red means you are going to burn and injure your children and isn’t that exactly the message they want mum’s and dad’s to believe;
Cheers
The NESDIS dataset uses only nighttime SST data. Why? The answer lies within the description of the data.
http://coralreefwatch.noaa.gov/satellite/methodology/methodology.html#sst
“Nighttime-only satellite SST observations are used to eliminate diel variation caused by solar heating at the sea surface (primarily at the “skin” interface, 10-20 um) during the day and to avoid contamination from solar glare. Compared with daytime SST and day-night blended SST, nighttime SST provides more conservative and stable estimate of thermal stress conducive to coral bleaching.”
Discussed the “hotness” of NESDIS “coral reef watch” SST data in this post:
http://bobtisdale.blogspot.com/2009/09/note-about-sst-anomaly-maps.html
The NESDIS webpage also cautions users about high latitudes of the “Coral Reef Watch” SST dataset: “Note that these anomalies are somewhat less reliable at high latitudes where more persistent clouds limit the amount of satellite data available for deriving both accurate SST analysis field and climatologies.” They do not go to the same lengths as other datasets to make corrections at high latitudes.
AGW “real estate” is no different from “real” real estate. To make a sale, sell the sizzle, not the steak. ;-0
Something very strange going on. NOAA has a positive relative anomaly north of Lappland and in the Black Sea. UNISYS has a negative relative anomaly in these places. Yet they agree in the Tyrrhenian Sea which is around zero/plus one on both scales.
Not just the colour bias, which I think does verge on propaganda in NOAA’s case.
gary says: “P.S. Are color blind people more apt to be skeptics? Curious because I am color blind.”
I’d guess yes, but not for the reason you suggest. If you are colour blind, you will be much more aware that people can see the same “data” and view it quite differently. You will also be very aware that your perception of something is subtly different from those with three colour vision, so you will not be so easily deluded that data is the same as your perception of the data.
All in all, I would suggest someone with colour blindness is much less likely to assume “the consensus” is correct and much more likely to be aware that someone’s perception of e.g. a cause behind a warming century is merely a false perception based on a lack of data.
This is a bit of a mess. Can you clear up which are actual temps and which are anomalies, thanks.
“Bruce of Newcastle says:
May 7, 2010 at 2:45 am
Something very strange going on. NOAA has a positive relative anomaly north of Lappland and in the Black Sea. UNISYS has a negative relative anomaly in these places. Yet they agree in the Tyrrhenian Sea which is around zero/plus one on both scales.
Not just the colour bias, which I think does verge on propaganda in NOAA’s case.”
The NOAA hotspot North of Lapland for example has been there fore ages, its a real difference in data. Also, it has nothing to do with colour scheme nor night temperatures as Bob Tisdale suggests, and the same goes for several other areas. No way is the Baltic over night suddenly warmer than normal end then in day time colder. Not realistic.
I think its perfect that we are open minded – a good scientific vertue – but we should not end up defending NOAA data when no arguments really support it. (But the info about night vs. day measuring itself is appreciated!)
“HR says:
May 7, 2010 at 3:29 am
This is a bit of a mess. Can you clear up which are actual temps and which are anomalies, thanks.”
All graphics shows ANOMALIES and are therefore comparable – when you of course consider the color legends.
And NOAA anomalies are far often more hot than UNISYS than the opposite.
Nick Stokes says:(May 6, 2010 at 11:45 pm)
“And Leif and Rattus are right. If you’re doing these comparisons you should at least acknowledge the difference in anomaly bases.”
So the question I have is this:
Why do different groups use different baselines?
Is it because:
a. They do not want their results easily compared to someone else
b. They are arrogant and believe only their results show something special
c. They have access to different data and do not want to share
d. No one can agree on a standard baseline for each type of anomaly chart
e. They want to deceive
f. Some other reason
Laying the colors aside: This is not the 1st time NOAA has been presenting data that the locals shake their heads over.
Behavior is compelling evidence, and there is a pattern.