From Frank Lansner at Hide the Decline
From DMI (Danish Meteorological Institute) we learn, that Arctic 80N-90N temperatures in the melt season this year is colder than average. This was the case last year too, while earlier years in the DMI analysis period (1958-2010) hardly ever shows Arctic melt season temperatures this cold.
This is how DMI temperature averages for Arctic 80N-90N melt season appears when plotted to allow compare over time:
Fig2 (When i speak of “the melt season” i refer to the period where temperatures 80N-90N are above zero Celsius. The green line above is the DMI temperature average, a little over 0,9 Celsius)
It seems that average Arctic temperatures 80N – 90N in melt season of the years 2004, 2009 and 2010 are around 0,4-0,5K whereas the temperatures in 1991 and 1993 where around 1,3 K. In general DMI´s data (if correct) reveals a cooling from the mid 1990´ies till today.
The 80N-90N area of the Arctic is practically always ice covered. Therefore, the 80N-90N is perhaps not so affected by heat from the other areas of the Arctic that has been still more ice free in the period 1995-2007. Im not sure why DMI shows such a cooling trend for the 80N-90N area, but it could appear as if the ice covered areas of the Arctic has its own history of temperatures? And how should GISS data from distant land stations account for this?
Here´s how GISS temperature appears when comparing 1991 to 2009 for the Arctic Polar region:
Fig3
The Arctic melt season is mostly June and July. For both months the GISS Arctic temperature trend 1991 vs 2009 shows warming around 0,3-0,7K which is in contrast with the DMI trends of cooling of around 0,7K for the region.
Is it basically a convincing idea to use land/city/Airport temperatures for temperatures at sea? Give it a thought:
Imagine you stand on a boat 12 km from land…
Fig4
You want to know the Air temperature in 2 meters altitude. Which temperature would be most precise, the water temperature around the boat or the temperature from land ( measured at the city airport… ) ?
Now imagine the same situation, but this time you are 1150 km from land. Which temperature would you rely most on, the water temperature around the boat or the temperature from land (city/Airport) 1150 km away?
Since 1987, James Hasen, and thus GISS, har used a 1200 km radius in their global temperatures based on meteorological stations and thus extended land temperatures to cover a considerable ocean area.
Below a compare of SST with the temperatures GISS use for ocean areas.
Fig5
1) Left: GISS land temperatures including land temperatures to cover ocean areas.
2) Right: As 1) but now for the ocean areas the actual SST measured by the Hadley centre are shown.
Both pictures are from july 2010. From this illustration we see, that ocean areas represented by SST are poorly reflected by GISS land temperature data and the idea of expanding land temperatures to cover ocean area appears challenged?
Read the entire article at Hide the Decline
the only graph I look at is the 30% extent one. That is going up and up rather than down at the moment, pointing to higher concentrations further into the arctic circle. If the 15% extent (ie around the edges) is diminishing but the 30% is increasing, it points to ice being pushed inwards rather than melting I would have thought?
Nylo wrote, “GISS deals with temperature anomalies.”
Sorry if the comment you’re referring to did not include the word anomaly. My mistake.
You continued, “What GISS says is, no matter what the true temperatures at the airport and at the sea are, if the airport temperature is 0,5K higher than normal for the airport, the temperature at the sea will probably be 0,5K higher than normal for that place at the sea.”
GISS in its standard product (LOTI) does not extend land surface out over the oceans for 1200km. They only do it with their dTs product and as I noted above, that dataset was prepared in the 1980s when SST data coverage was poor. GISS also has a disclaimer on its Surface Temperature Analysis webpage:
http://data.giss.nasa.gov/gistemp/
It reads, “Note: LOTI provides a more realistic representation of the global mean trends than dTs below; it slightly underestimates warming or cooling trends, since the much larger heat capacity of water compared to air causes a slower and diminished reaction to changes; dTs on the other hand overestimates trends, since it disregards most of the dampening effects of the oceans that cover about two thirds of the earth’s surface.”
Also, the land surface station data (GHCN) used by GISS does not all come from airports.
Nylo, you write: “What GISS says is, no matter what the true temperatures at the airport and at the sea are, if the airport temperature is 0,5K higher than normal for the airport, the temperature at the sea will probably be 0,5K higher than normal for that place at the sea.”
Yes, we talk anomalies, but what i showed was that anomalies from land does not match anomalies at sea well.
I showed this for the Arctic and here the example exactly showing that anomalies projected from land does not resemble anomalies at sea:
http://hidethedecline.eu/media/ArcticGISS/fig5.jpg
So the whole discussion is indeed based on anomalies already.
K.R. Frank
Bob, I too have considered that ERA-40 data ends in 2002 and this might be part of the explanation.
Fact is, DMI today shows Arctic temperatures in melt season around 0,5 K and they show higher temperatures for earlier years like i illustrated. So if this is not interesting, then you are saying that DMI is presenting data wrongly? DMI did not consider the shift from one dataset to the next and therefore shows colder temperatures today for the Arctic?
Billy Liar says:
August 5, 2010 at 6:39 pm
anthony holmes says:
August 5, 2010 at 3:46 pm
Well , on checking the north pole web cam , which I have been assured by a member of the camera crew is correct , it is showing the cameras temperature is 11 centigrade …
Was it the leprechaun who lives inside the camera that told you that?
–
Evidently the leprachauns name is Nancy , so its a Lady Leprrachaun ! Here is the question I asked below , and Nancys answer .
On the north pole web cam there is an internal temperature display on screen , today it was 10 degrees centigrade . Is this the temperature inside a fixture that houses the camera and is it artificially heated , or is it the actual temperature at the north pole , it is very confusing and I am suprised there seems to be no information about it . Thanks Anthony.
Dear Anthony,
Here is the answer to your question, from the website http://www.arctic.noaa.gov/gallery_np_questions.html:
Temperature, Pressure, etc.: The temperature and other environmental measurements you see in the left corner of the picture are correct. The temperature shown on the image is the temperature of the camera, and may be warmer than the surrounding air temperature (think about how your car heats up on a sunny day). Because it is spring, the temperatures are warmer than they are in the middle of winter, when the temperatures are near -30 deg C. Also the ocean water below the ice floes is near the freezing point for salt water (-1.7 deg C), so this helps keep the temperatures higher than they would be on land. Scientific measurements of temperature and other environmental parameters are found under “Weather Data” for each deployment year, under the photos on the Web Cam home page.
You can find 2010 Weather Data and Drift Track info from North Pole Environmental Observatory website:
Web Cam #1: 2010 Weather Data from co-located instruments & Drift track (green line labeled POPS-13)
Web Cam #2: 2010 Weather Data from co-located instruments & Drift track (red line labeled PAWS)
Thank you for your question and interest in our website! Regards, Nancy Soreide
This discussion is a storm in a tea cup. It is a graph averaging above zero temperatures taken from DMI graphs. I’m not sure how these averages were derived, from real data or guestimates from the graphs. Whichever way, to me it seem quite irrelevant, because all it shows is surface temperatures above ice ranging between 1.25C and .04C. I’d consider that normal.
Apparently it did not prevent the large melt in 2007 or the general decline. This is well within the -0.5C to +0.5C range you considered as ‘normal’ in the SST map colour scheme thread. The latest image from http://www.iup.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png up to 55N looks like an assaulting army stalking 80N to 90N.
Quick question: won’t the latent heat of melting ice tend to pull down the air temperatures?
Can someone explain why the buoys shown on the NPEO’s Bouy Drift Track Map took a a 90 degree turn recently after drifting almost in a straight line for months?
http://psc.apl.washington.edu/northpole/index.html
“…ocean areas represented by SST are poorly reflected by GISS land temperature data and the idea of expanding land temperatures to cover ocean area appears challenged?”
Heck with that. We don’t even know that expanding land temperatures to cover the LAND area is right.
Fuzzylogic19
There was very little melt in 2007 north of 80N. Your assumption is incorrect.
Question: Why is Chef “cook the temperature books” Hansen using estimates of Arctic temperatures due to closing of GHCN stations, when DMI has actual measurements going back to 1958?
Answer: What’s the use? If you add wine to sewage, you still end up with sewage.
Frank Lansner asked, “So if this is not interesting, then you are saying that DMI is presenting data wrongly?”
No. You are reading too much into what I wrote.
My interests are SST, OHC, ENSO, and things of that nature. And occassionally I’ll write about other topics like the differences between the Hadley, GISS, and NCDC data. I’m not necessarily interested in sea ice or the Arctic, but you are. We have different interests.
The only reason I commented this thread was because of the reference to the wrong SST dataset in the post.
Fuzzylogic19 says:
” to me it seem quite irrelevant, because all it shows is surface temperatures above ice ranging between 1.25C and .04C. I’d consider that normal.”
For the AGW crowd these Arctic temperatures appears rather important… Ask the AGW why Arctic temperatures are so important.
The temperatures does however give the impression, that the ice retreat has indeed been strongly influenced by the special winds that occurred mostly in the period 2000 – 2007.
K.R. Frank
K.R. Frank
Frank Lansner says:
August 6, 2010 at 9:36 am
Fuzzylogic19 says:
” to me it seem quite irrelevant, because all it shows is surface temperatures above ice ranging between 1.25C and .04C. I’d consider that normal.”
For the AGW crowd these Arctic temperatures appears rather important… Ask the AGW why Arctic temperatures are so important.
The temperatures does however give the impression, that the ice retreat has indeed been strongly influenced by the special winds that occurred mostly in the period 2000 – 2007.
—…—…—…
It’s good to see this DMI trend plotted: The data flatly contradicts completely Hansen’s mythical +4 degree Arctic temperature “rise” over the past few years. True: DMI is a compiled database: It’s all one set of completely independent temperature records since 1958. But now, with this long-term data set proving that summer (melt season) temperatures at latitude 80North not only NOT rising as CO2 levels rose since 1958 – but actually falling over the same period – we have another nail falsifying the Hansen’s CAGW theory.
What is needed is the standard deviation of this same temperature record: That too will show how closely linked – how little “error” and randomness is in the summer temperatures ion the Arctic.
However …. This is the “summer” (melt season data trend.
Hansen will no doubt claim that yearly average temepratures are rising catastrophically. (He will have too, if he is to stay in business.)
DMI Winter Arctic at 80 North temperatures may – or may not – have risen since 1958 but very clearly have a much, much greater randomness. +/- 10 to 15 degrees jumps are common (possibly some (all ? – No, probably not!) are caused by missing “M” metadata “minus zero” numbers on the manual transcription records.
So. The question is raised: What is the yearly trend of the winter Arctic temperatures since 1958? What is the standard deviation of those daily temperatures? What is the CAGW implication of a steady trend? A rising winter temperature? (A declining temperature?)
There are two webcams in the Arctic Ocean. In a recent comment, I posted the co-located temperature data link for camera #1. camera #2, PAWS, the one on your ice page, is at:
http://psc.apl.washington.edu/northpole/PAWS_atmos_recent.html
The temperature listed on the image IS the internal temperature of the camera. The temperature at Camera #2 seems to run slightly warmer than #1 by perhaps 0.5 degrees C, even though it’s 100 miles further north.
The drift track and current position fo both cameras is at:
http://psc.apl.washington.edu/northpole/DriftTrackMap.html
Hi RACookPE1978!
Thanks for input!
You write: “So. The question is raised: What is the yearly trend of the winter Arctic temperatures since 1958?”
Its true, after this the Winter trends, the annual trends become interesting to know as well…
K.R, Frank
PS: when Bob Tisdale writes above that there is a reference to a wrong SST dataset, its just the text under fig 5, it should have been “Hadley/Reynolds” and not just “Hadley”. (However, these 2 datasets are really very similar.)
Frank Lansner says: “when Bob Tisdale writes above that there is a reference to a wrong SST dataset, its just the text under fig 5, it should have been ‘Hadley/Reynolds’ and not just ‘Hadley’. (However, these 2 datasets are really very similar.)”
Actually, they are not similar. HADISST uses in situ measurements (ships and buoys)from 1870 to 1981. Due to the sparseness of SST measurements much of the data is interpolated. From 1982 to present, HADISST also includes satellite-based SST measurements, reducing the need to interpolate. On the other hand, the Reynolds OI.v2 SST data is only available in the satellite era, from Nov 1981 to present. It also uses in situ and satellite data, which would make some think the Reynolds OI.v2 and HADISST datasets should be similar during the satellite era. But they are not similar. The following is a graph of SST anomalies for an area of the South Pacific.
http://i35.tinypic.com/2lc1t11.jpg
Note how the variability of the Reynolds OI.v2 data is much greater than that of the HADISST data. The Reynolds OI.v2 data also has a significantly higher trend than the HADISST data on a global basis.
RACookPE1978 says:
August 6, 2010 at 12:25 pm
Frank Lansner says:
August 6, 2010 at 9:36 am
Fuzzylogic19 says:
” to me it seem quite irrelevant, because all it shows is surface temperatures above ice ranging between 1.25C and .04C. I’d consider that normal.”
For the AGW crowd these Arctic temperatures appears rather important… Ask the AGW why Arctic temperatures are so important.
The temperatures does however give the impression, that the ice retreat has indeed been strongly influenced by the special winds that occurred mostly in the period 2000 – 2007.
***
Arctic temperatures are important, but in the context of this thread, I’ll point out that (1) the 2010 melt season is not yet over so the claim about 2010 is pre-mature. If you look back at 2009, you’ll see that the temperature at the beginning of the melt season stayed closer to the melt point and then rose. In calculationg the average melt season temperature was it based on a fixed number of melt days, or the actual number of days? What is considered the start of the melt season? Is it the first rise above the melt point, or the second point if it drops below again for a few days. Identical argument for the end point of the melt season. Have you looked at the other end of the graph? Just look at say day 0-150 and 250-360. In 1958 this showed variation between 233K (-40C) and 253K (-20C) compare with say 2009 242K (-31C) and 259K (-14C). Look at the other end; days 250-360. From 2000 to 2009 nearly all temperatures are above average. Take 1958 to 1967 and only 50% or less of the temperatures are below average.
Steve’s graph remains deceptive trying to make an issue where there isn’t. Temperature measurements withing 80N and 90N will vary with cloud cover, snow on ice and age of ice exposed. When I express concerns about .5C temperature rise it relates to sea and land temperatures over the longer term. To raise sea temperature by that much requires gigantic amounts of energy. From the DMI graphs I conclude that the melt season temperature is relatively stable (for now) but that the freezing season temperature average has risen a lot, meaning 6-9C. The impression is created of talking about the arctic in general on the premise of small temperature changes in an area of continuous ice, where temperature fluctuations are limited to begin with. It remains a storm in a tea cup.
stevengoddard says:
August 6, 2010 at 9:12 am
Fuzzylogic19
There was very little melt in 2007 north of 80N. Your assumption is incorrect.
***
That depends on what melt we’re talking about, extent or volume. Frankly I would not expect a lot of change (extent) at 80N and 90N, it is after all at the melt centre, be it fighting a losing battle. Ice will melt in-situ and from the edges or driven out or any combination thereof. I think that the DMI graphs you used have opened a pandora’s box, the important part is what is happening during the freezing season.
Hi Fuzzy!
its true the melt season is not over yet. That why I put a conservative estimate for 2010 at 0,5K. Everthing points to something nearer 0,4K perhaps even an all time record low for 2010. But my graph shows a trend 1991 – 2010 that most certainly is not prematurely illustrated.
So, I had to add a consevative value for 2010 as 10-12 days where missing, and so everything points to that i have underestimated this years cold in the Arctic 80N-90N – i will update in weeks time.
When i alowed my self to put a conservative value for 2010 its because the rest of the melting season should behave like a natural disaster + an atomic bomb to really change things radically now 🙂
Already by now my consevative value of 0,5K is too high.
K.R. Frank
K.R. Frank
Fuzzy, I agree with you a little about opening this data could be a pandoras box. But reality is: These data actually seems to be part of reality – dont you agree?
These data contributes to a more nuanced picture of the Arcit temperatures, and I think what we need is a more nuanced picture. For instance the GISS temperatures just claims that the area is warming massively – when its not. Is that optimal for a scientific thinking person simply to have wrong information?
The pandora´s box it would be if everybody now said: “the Arctic has been cooling since 1991” – I guess thats what you fear?
I think its relevant to know, that the ice covered areas up there at least seems not to have warmed – and this could support that the ice loss is due to winds and currents rather than only melting.
Also – when GISS make their temperature maps, i do think that they should be as precise as possible – why else make them?
Why do we want a dark red area for temperatures in an area that should perhaps be light blue etc.?
K.R. Frank
RE: Query by RACookPE1978 about temp trends outside melt season.
Tom Moriarty at Climate Sanity produced a highly commendable “reverse engineered” version of the temperature trend graphs that appear on the DMI site.
Mr Moriarty’s dataset is available at…
http://climatesanity.wordpress.com/2009/09/09/dmi-arctic-temperature-data-does-show-increasing-temperature-trend/
In this article, he describes in some detail the extraction technique employed.
As a newcomer to WUWT, I do not have first hand information, but, from what I can glean from the article, it appears that an animation of the DMI figures has already been posted on this site. Whilst such animations can undoubtedly be very illuminating, they are not necessarily the optimum technique when faced with noisy data. My approach to the analysis was therefore somewhat more traditional.
Mr Moriarty’s dataset is basically a flat file extending from 1st Jan 1958 to 6th Sep 2009 that can be easily downloaded into Excel. As one can see from the end date, this was 116 days shy of a full 52 year dataset, roughly equivalent to about 0.6% missing. (N.B. Mr Moriarty’s data actually has two entries per day, presumably at the 00z at 12z measurement windows.)
In a fit of creative accountancy, I “in-filled” the missing days by taking the corresponding unweighted average temperature for each of the 10 preceding years. (i.e. The temp used for (say) 7th Sep 2009 was the arithmetic mean of the temps on that date between 1999 and 2008 inclusive.)
As noisy daily data spread over a period of 52 years is a little difficult to interpret, I simplified things by aggregating the data into units we are all familiar with – calendar months. Linear regression on the ensuing 12 x 52 dataset gave the following decadal trends… Jan +0.76C/decade, Feb +0.71C, Mar +0.24C, Apr +0.31C, May +0.18C, Jun -0.08C, Jul -0.03C, Aug -0.07C, Sep +0.28C, Oct +0.68C, Nov +0.53C, Dec +0.63C/decade.
The daily mean temperatures shown on the DMI site are derived from the ERA 40 product, and this uses a 45 year baseline extending from 1958 – 2002. As the summer (Jun – Aug) trends are negative, it is hardly surprising that the current temperature anomalies are mirroring this behaviour.
If these figures are plotted on a graph it still looks like a dog’s dinner, so I took two additional steps to filter out some more of the extraneous noise signal. Firstly, I aggregated the data further into seasons, rather than months. These, unsurprisingly, were Winter (Dec – Feb), Spring (Mar – May), Summer (Jun – Aug) and Autumn (Sep – Nov). The additional step was to further smooth the figures by using an unweighted rolling 5 year average. (Obviously, this step reduces the notional length of the dataset from 52 to 48 years.)
The resulting decadal trends came out as follows… Spring +0.3C/decade, Summer -0.05C, Autumn +0.47C, Winter +0.68C, Annual +0.35C/decade
When I look at the graphs of these 5 data series, my interpretation is that it looks like a multi-decadal oscillation superimposed upon a pronounced warming trend. (Except, of course, for summer.) Obviously many people will disagree. Alternative interpretations could certainly involve very long term oscillations, Little Ice Age Rebound hypothesis (shame about the acronym) or simple disputation of the original data.
As I may well have made some stupid mistake whilst number crunching, perhaps someone on this site might care to repeat my reanalysis and post their findings, including, if possible, the graphical representation of the monthly, seasonal and annual trends.
1) What is the special significance of daily average temperatures above 0 degrees C? Sea ice melts at -1.8C, and melting would presumably begin when this temperature is exceeded at some part of the day (while daily averages are still below -1.8C). The only effect of this limit seems to be to restrict the analysis to approx 1/6 of the total data without any basis in nature I can immediately think of.
2) What was the exact methodology used to produce the graphed values? It’s all good and proper to blast climate scientists for “hiding their data and methods”, but here we get absolutely zero on the methodology used, apart from the somewhat spurious 0C limitation.
Looks like a pretty crude case of cherry picking. The warming trend in the remaining 5/6th of the data left out is quite strong, when you look into it.
PN, you write: “What is the special significance of daily average temperatures above 0 degrees C? Sea ice melts at -1.8C…”
PN – (why anonymous?) – I showed that high quality data, perhaps the best available, shows a cooling trend 1991 and foreward till today in for the melting season in the area 80N-90N. This is a piece of inforation in the scientific puzzle and then its up to you and everybody else to interpret and use this information. If you think this is an irrelevant piece of information, fine with me – I dont.
Method: its described earlier in the comments – i think i will add it to the article.
In general ERA-40 data globally shows much less warming than CRU, GISS etc. See:
http://hidethedecline.eu/pages/posts/the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-180.php
Then you say that the rest of the period (outside the melt season) shows something quite different. PN, please show me the trend for the non-melt season that you refer too – can you provide a link?
Anyway, I think its very interesting that melting season temperatures in the ice covered area have been cooling in the same time that other Arctic areas have been melting more and more until 2007. This supports that this “melting” perhaps is not just a melting but rather the results of the unusual winds and currents in the period 2000-2007 just as NASA them selves declared in october 2007.
And honestly, GISS temperature data maps of glowing red Arctic 80N-90N should not allways be that red for the Arcitic – but thats irrelevant too i suppose.
The info on ERA-40
http://hidethedecline.eu/pages/posts/the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-180.php
see part 3 chapter 5.2
K.R. Frank