UPDATE: the question has arisen about “occupied” aka “manned” weather stations in Antarctica (Stevenson Screens etc) versus the Automated Weather Stations. This picture on a postage stamp from Australia, celebrating the Australian Antarctic Territory in 1997, may help settle the issue. Note the Stevenson Screen near the “living pod” on the right.
Here is the larger photo of the first day of issue card, the Stevenson Screen is also just visible above the snowbank in the lower right. Rather close to human habitation I’d say. Looks like its in the middle of an AHI (Antarctic Heat Island).
Here’s another picture of a Stevenson Screen close to a building in Antarctica, from the British Antarctic Survey:
![[10004058]](http://www.photo.antarctica.ac.uk/external/guest/image/water/70/10004058)
Location: Fossil Bluff, Alexander Island
Season: 1994/1995
Photographer: Pete Bucktrout
It seems that folks are all “wild about Harry” over at Climate Audit, with the revelations occurring there, and no good kerfluffle would be complete without some pictures of the weather stations in question. It seems a weather station used in the Steig Antarctic study , aka “Harry”, got buried under snow and also got confused with another station, Gill, in the dataset. As Steve McIntyre writes:
Gill is located on the Ross Ice Shelf at 79.92S 178.59W 25M and is completely unrelated to Harry. The 2005 inspection report observes:
2 February 2005 – Site visited. Site was difficult to locate by air; was finally found by scanning the horizon with binoculars. Station moved 3.8 nautical miles from the previous GPS position. The lower delta temperature sensor was buried .63 meters in the snow. The boom sensor was raised to 3.84 m above the surface from 1.57 m above the surface. Station was found in good working condition.
I didn’t see any discussion in Steig et al on allowing for the effect of burying sensors in the snow on data homogeneity.
The difference between “old” Harry and “new” Harry can now be explained. “Old” Harry was actually “Gill”, but, at least, even if mis-identified, it was only one series. “New” Harry is a splice of Harry into Gill – when Harry met Gill, the two became one, as it were.
Considered by itself, Gill has a slightly negative trend from 1987 to 2002. The big trend in “New Harry” arises entirely from the impact of splicing the two data sets together. It’s a mess.
So not only is there a splice error, but the data itself may have been biased by snow burial.
Why is the snow burying important? Well, as anyone skilled in cold weather survival can tell you, snow makes an excellent insulator and an excellent reflector. Snow’s trapped air insulative properties is why building a snow cave to survive in is a good idea. So is it any wonder then that a snowdrift buried temperature sensor, or a temperature sensor being lowered to near the surface by rising snow, would not read the temperature of the free near surface atmosphere accurately?
As I’ve always said, getting accurate weather station data is all about siting and how the sensors are affected by microclimate issues. Pictures help tell the story.
Here’s “Harry” prior to being dug out in 2006 and after:
Harry AWS, 2006 – Upon Arrival – Click to enlarge.
Harry AWS, 2006 – After digging out – Click to enlarge.
You can see “Harry’s Facebook Page” here at the University of Wisconsin
It seems digging out weather stations is a regular pastime in Antarctica, so data issues with snow burial of AWS sensors may be more than just about “Harry”. It seems Theresa (Harry’s nearby sister) and Halley VI also have been dug out and the process documented. With this being such a regular occurrence, and easily found within a few minutes of Googling by me, you’d think somebody with Steig et al or the Nature peer reviewers would have looked into this and the effect on the data that Steve McIntyre has so eloquently pointed out.
Here’s more on the snow burial issue from Antarctic bloggers:
The map showing Automated Weather Stations in
Antarctica:
Click map for a larger image
The Gill AWS in question.
From Polartrec
Theresa was placed at this location partly to
study the air flow in the region. Looking out the window of the plane we can
definitely see the air flowing!!! Jim estimates the wind at about 25 miles per
hour.
Wind blown snow at Theresa
With the temperature around 0F the wind chill
was about 20 below, it is obvious this is going to be quite a chore.
Starting to dig out Theresa
The weather station has not been working, so
George needs to figure out what is wrong with it and then fix it. The station is
almost buried in the snow so we will also need to remove all of the electronics,
add a tower section and then raise and bolt all of the electronics and sensors
back in place.
George unhooking the cables.
After refueling the plane, with the fuel in
the 55 gallon drums, Jim and Louie helped dig down to the electronics boxes that
were completely buried plus they built us a wind break that made huge difference
in helping us not be so cold. After about 4 hours we are almost through. As I am
hanging onto the top of the raised tower in the wind, one bunny boot wedged onto
the tower bracing, the other boot wrapped around the tower, one elbow gripping
the tower, my chin trying to hold the wind sensor in place and both bare numb
hands trying to thread a nut onto the spinning wind sensor I really appreciate
the difficulty of what is normally Jonathan’s job. After checking to make sure
Theresa is transmitting weather data we board the plane and head to Briana our
second station.
Notice the difference between this
picture and the first one of Theresa.
From Antarctic Diary
More movement
It’s been another flat-out week. The vehicle team have dug
up and moved the Drewery building, which was getting do buried snow was
almost up the windows. Team Met have been on the move too – all the
remaining instruments are now bolted securely to the Laws roof, so we headed
up the the Halley VI building site to relocate the weather station.
Jules starts digging out the weather station
Only 15km away, the Halley VI site looks a lot like Halley V. It’s flat,
white and snowy. Very snowy. The weather station had about 1.5m built up
around it!
Jules and Simon recovering the solar panel
In the hole!
The weather station was a survey reference point for the build project so we
had to find a suitable replacement. Could this be Antarctica’s first
pole-dancing venue?
Penguin Party memories…
After an hour or so sweating it our with shovels, the weather station popped
out and was loaded onto the sledge. Like the reference point, the station’s
new location had to be precise as vehicles are banned from the upwind
section of the site to keep that area ultra-clean for future snow-chemistry
experiments.
Weather station on the move
Driving on a compass bearing and GPS track, we found the new site just under
a kilometre away.
The final setup
UPDATE: here’s another buried station story from Bob’s Adventures in cold climes. Apparently this station is used as a reference for some sort of borehole project.
I dig weather stations
My main task for today was to get a start on raising my weather station. I’d installed it 2 years ago, and with the high accumulation at Summit, it’s getting buried. The electronics are all in a box under the snow, and the only things visible at the surface were the anemometer for measuring wind speed and direction, the thermistor for measuring air temperature, and the solar panel to keep the batteries charged.
The buried weather station. The flat green bit is the solar panel, which was about 1.5 meters off the surface when I installed the station. Can you guess why I would mount it facing down?
In the morning I downloaded all the data from the station, and checked to see that it was all in order. Then it was time for digging. I’d carefully made a diagram when I inastalled the station, so I knew exactly where to dig. A couple of hours later I’d found my box!
At the bottom of the pit with the datalogger electronics.
I brought everything up to the surface, and then was about to fill in the pit, when I realized at least one more scientist at Summit might want to make measurements in it; the pit’s already dug! So tomorrow I’ll help Lora with some conductivity measurements, then fill in the pit, re-bury the box just beneath the surface, and it’ll be ready to go for another 2 years!
And there’s more….
The Australians seem to have AWS problems as well. From the Australian Antarctic Division:
On Monday two groups headed out, with Largy and Denis going up to the skiway to check on the condition of the equipment stored there for the winter and beginning preparations for the coming summer flying season.
Bill, Brian and Ian went up to the Lanyon Junction Automatic Weather Station (AWS) to check its condition and retrieve some of the sensors in preparation for the annual servicing of the various remote units.
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And the University of Maine, participating in USITASE, has the same troubles, they write:
We reached our first major destination at the end of today’s travel, the site of the Nico weather station. There are several automatic weather stations spread out over the surface of Antarctica. These stations measure things like temperature, wind speed and wind direction and then relay this data back to scientists via satellite. Anything left on the surface of the snow will eventually be drifted in and buried by blowing snow. This particular weather station (NICO) has not been seen in several years. They tried to locate it via airplane a few years ago and were unsuccessful. Our task was to find the weather station, record its position with GPS, and mark the location with flags so that in the near future, the weather station can be raised and serviced.
We arrived at the coordinates of the station around 10 pm. Our initial scans of the horizon were not productive, so Matthew and John took the lead tractor (with our crevasse-detecting radar) out to survey a grid near our stopping point. The radar should detect a large metal object like a weather station, but the survey was also unsuccessful. After a fine pasta and tomato sauce dinner, John went outside for an evening constitutional. He saw a shiny object out in the distance – further inspection with a pair of binoculars determined that it was the top of the NICO weather station! Several of us marched out to the station, which was actually about a half mile distant, marked the location with bright orange flags and recorded the position via GPS for future reference. Only the top foot or two of the station was still visible. John was in exactly the right place at the right time to see a reflection from this object while we were near the kitchen module, and so allowed us to complete our first task successfully.
Tomorrow, we drive on.
This regular burial and digging out of stations brings the whole network of AWS stations to be used as sensitive climate measurement stations into question.
Chris V. (18:27:00) :
“And it is certainly possible for snow burial to introduce a cooling bias. Most snow falls during Antarctica’s winter. ”
Contrariwise, most snow in Antarctica falls during the summer. Winter is very cold and clear.
tty (02:03:11) :
Chris V. (18:27:00) :
As i understand it the snow gets moved around a lot on the surface by the wind, suppose that happens year round.
Simon Evans (16:50:03) :
I’m sure you can see my point. The impression is that the obvious limitations in Antarctic data are only challenged if it suits the agenda.
Correct. and this is precisely what Steig et al set out to do. They challenged and spliced the data to suit their warming agenda.
Simon, may I make a suggestion. Please, lose the anger within your posts, all it does is frustrate others. Instead, talk to us like adults, I’m sure you’ll get a better response from people.
Simon Evans (17:06:33) :
I certainly don’t see why the snow issue necessarily implies a warming bias over time.
Just speculation, but I would suggest that all stations started out life above the snow, now if there are stations regularly buried, then this would be a reason. As I say, just speculation.
E M Smith that’s another brilliant post. You’ve done so many brilliant posts here, you need to think about publishing IMHO… with pictures to keep the “kitchen science” feel and to be accessible.
I reckoned school science hit problems the moment “Health and Safety” interfered and made people wear masks, distancing themselves from that important moment of participation with the bangs, the smells, the flashes. Short-time no doubt some safety was improved; but in the real School of Life, it’s far more dangerous NOT to learn to cope with the hard edges – where one might realize, beforehand, inherent biases in AWS.
EricH, typo, it’s http://www.penhadow.com – p not b. Pen’s story is fascinating – in line with the above – but then Pen has more experience than most of the Arctic sea ice, and he has watched with dismay the changes taking place there over the past two decades – open water where there was none, seals and bears in places where they never used to be, changes in the thickness and colour of the ice itself. The result is that Pen has now become a leading exponent on the need for change – oh dear, seems like he hasn’t heard of Nansen’s voyages or the MWP.
For a laugh, and for IMHO damning evidence, look at Warming Antarctica by Paintwork
E M Smith, the post I meant was the one BEFORE your C**** post which looks like it belongs better at CA. We collided in hyperspace, nice to meet you.
Ric Werme (19:07:26) : I don’t understand his rant about archiving data, there are 30 year-old source archiving systems that GISS doesn’t use and more modern ones that work just fine over the Internet. I’m sure there are plenty of students at Columbia and Washington who use them today and could set them up for “the team” in to time at all.
rcs / cvs and several others have been on every Unix, Linux, *ix box for just about forever. ‘check in’ and ‘check out’ commands are near trivial. See:
http://kuparinen.org/martti/comp/cvs/cvs.html
for an example ‘tutorial’ (though it really only takes a couple of seconds to learn ‘cvs ci foo’ to check in a copy and ‘cvs co foo’ to check out a copy of foo…
RealClimate (Gavin) respond here. Turns out the conclusions of the study are not dependendent on the automated weather station readings:- the findings are robust even if detrended AMS data is used …
Specifically, given that the results using the satellite data (the main reconstruction and source of the Nature cover image) were very similar to that using the AWS data, it is highly unlikely that a single station revision will have much of an effect on the conclusions (and clearly none at all on the main reconstruction which didn’t use AWS data). Additionally, the quality of the AWS data, particularly any trends, has been frequently questioned. The main issue is that since they are automatic and not manned, individual stations can be buried in snow, drift with the ice, fall over etc. and not be immediately fixed. Thus one of the tests Steig et al. did was a variation of the AWS reconstruction that detrended the AWS data before using them – any trend in the reconstruction would then come solely from the higher quality manned weather stations. The nature of the error in the Harry data record gave an erroneous positive trend, but this wouldn’t have affected the trend in the AWS-detrended based reconstruction.
anna v: “I read about wind chill above, in one of the descriptions of digging out a station.”
wind chill is not tempearture…
With all this diggin, why not use satellite data?
Robert Wood (17:08:36)
Robert, your idea has a basis but needs a modification. You left a factor out of your calculations, wind speed in the Antarctic averages 44mph with high speeds of 190mph+ this is why if you study the photo’s you will see that the towers are tide down, this would make for prohibitive expense and mechanical failure, for a piston to lift or lower the instruments, perhaps extending the height of the tower a meter or two would achieve the results you are proposing.
George E. Smith (16:41:08)
Re Charles the moderator.
Charles, any chance of getting a copy of the key to your toolbox?
The weather station at Fossil Bluff, Alexander Island has a couple of interesting features. It is a little tough to tell how far from the building the screen is due to the photograph, looks like there may be a small valley between the two. The important point is the two black barrels next to the Stevenson’s screen, they are probably fuel barrels, but what if another weather station as drug a burn barrel with-in range?? Of course having big black objects next to the weather station might bias the temperate readings a bit on nice sunny days even without burning any garbage..
Amazing. Simon Evans writes: “Why the concern about this now, following Steig’s paper which found a warming trend, when there was no concern expressed about it before, when the general meme was that the Antarctic was cooling? Why do you energetically challenge findings that suggest supposed warming whilst uncritically accepting any evidence of supposed cooling?”
This is clearly an an effort to call into question the motives and intellectual honesty of people who post and comment on this site. And yet, when a different commenter makes a snarky comment about Simon Evans, he gets all huffy about “ad homs”.
Simon, you can’t have it both ways. Anthony gets kudos for responding to you as if your question were somehow a legitimate one based on science. It wasn’t. Because your question contained a false assumption — one which was disparaging of Anthony and others.
You have been treated better than you deserve. If you don’t want people to personalize a dispute, perhaps you shouldn’t have been personally disparaging in your initial comment.
MattN (03:19:48) :
wind chill is not tempearture…
Wet a thermometer in the wind and ask it. Of course it lowers the temperature by evaporating any humidity from surfaces/body. Have you not seen water cooled air conditioners?
I was just thinking that maybe when there is a lot of wind what is being measured is not ambient temperature, but some sort of wind chill due to the evaporation of ice from the counter surfaces.
I am just offering a process by which errors could be towards cooling rather than heating.
Ice in the Desert
Consider that frost can form on the ground on a clear and still night even if the air temperature is above freezing. On a ‘clear’ night, the ground is radiating heat out to space with limited return radiation which allows for the surface to be colder than the air above it. Ric identified the air and surface relation in his excellent post earlier Ric Werme (18:50:20) : “Dew only forms when the ground temp is cold enough so that air is being chilled to less than the dewpoint.” The cooled air would only need to be a thin layer above the surface, and could be significantly different from the measured air temperature.
How much different might the surface be from the measured air temp?
There is the ‘Ice in the Desert’ phenomenon. I first ran into this as an engineering thermodynamic question, posed something like: How warm can the night time desert air be above a thin pool of water and still have the water freeze? In the desert, with limited moisture in the air column above, there is limited re-radiation back to the surface, so more heat is lost to space. As I recall, the book answer was that the air temperature could be in the mid-40s F, so something like +10F (or +6C) above freezing and still form ice in the pool. I have since seen estimates that the air temperature could be as high as 60 F (about +15C above freezing) to 90F (+30 C) depending on the starting configuration, allowance for evaporation, and use of an apparatus to make the ice. Apparently both the Romans and Egyptians were able to make over-night ice using equipment as simple as a clay tray or a pit technique.
Remember that this only happens on a still night. If the wind is blowing, the relatively warmer air mixes down to the surface and convective heat transfer becomes significant. The energy lost to space is ‘shared’ between the surface and the air above, so the surface does not cool as much, if at all, relative to the air temperature.
So a couple of thoughts – Ric is probably right about the solid CO2. It would be quite a stretch to get extra cooling from -90C to -135C even with the surface radiation heat loss. On the other hand, per E.M.Smith (22:43:49) : “the CO2 / water clathrate phase has a temperature at 1 bar of about -55 C as I read it.”. That would suggest that it doesn’t need to be -90C to get a CO2 solid. With extra radiative surface cooling of say 5 deg C, the clathrate might form in areas where the measured air temp was ‘only’ -50C.
It would be nice to recap the story
(1) up to 2004, NASA records show the bulk of Antarctica cooling and just the peninsula warming.
(2) this makes sense since a strong warm ocean current arrives in the vicinity of the “horn”, and gets “milked” and shows the global warming record that has been true for the rest of the planet at this time. However, the rest of Antarctica’s cooling is in line with the Svensmark hypothesis, predicting cooling over permanent snowfields due to less cloud cover exposing the higher-albedo ice.
(3) Now the 2004 NASA article also shows the climate model with Antarctica warming even more than the rest of the planet
(4) since 2004, NASA’s Antarctic pictures have gotten to look ever warmer
(5) yet the ice extent around Antarctica has been reaching record highs
(6) and sea surface temperatures have been falling for the last decade, after a steady rise from 1920
(7) a major skeptic contention, and thorn in the AGW theory, is the evidence of Antarctica cooling during the “global warming” period, in opposition to what models predicted.
(8) in 2009, bingo! Antarctica temperatures HAVE been rising – claim the warmists in Nature magazine – in opposition to what even they were claiming earlier.
(9) very soon, very fishy data problems are discovered in the (landbased) data cache – and are corrected in a way that is very funny but compounds the suspicion
(10) we haven’t yet seen checks on the satellite info, or on the end significance of these fishy data. But we’re trying to cooperate to tease all this out – since we doubt the official science, we’re doing the science ourselves, openly, and with invitations to the official scientists to cooperate.
Wouldn’t locating a dark solar panel just a foot or so below the temperature sensor, be a potential source of warming bias?
E.M.Smith (01:43:46) :
“Steve McIntyre’s site may be a better place for this.”
No, I disagree – WUWT is the perfect place to post this. In fact, E.M. Smith should be given permitted to post this as an article. After all, GISTEMP is the source of the infamous GISS temperature “anomalies”.
I’m happy to see that others are starting to tackle GISTEMP again and see it as the junk code that it is. I thought Model E was as bad as it gets, but I was wrong – GISTEMP beats it by a mile.
By the way, I find it interesting that NASA employees like Gavin Schmidt will toil diligently on a Sunday night to be the first to alert the BAS of the Harry debacle, and yet can’t find the time to document and validate their software. Priorities…
Eight-year-old Child- But, Mr. Gore you ARE an older person, aren’t you?
OT… But you gotta see Peanuts comic strip this morning… Hockey players are trying to take over the world… until their curved hockey sticks are made illegal and the world is saved… Climate Change commentary??? Not sure.
Re EM Smith (01:43:46)
To EM Smith, Charles the Moderator, and Lucy Skywalker,
I think some of this brilliant detective work of Mr. Smith’s is absolutely essential to WUWT. Not only is the readership is larger, but it is more diverse. Climate Audit, with its own excellence, draws mainly the highly-educated and trained professional readership. Someone like myself, only a “scientist” in values and method, can read CA regularly, but understanding the material…..?
EM Smith is helping to show millions+ (per month now) what fools we be if we believe ANY of the Global Warming Apocalyptics. And I remain a sceptic of both warming and cooling “theories”. Show me the goods. Give me the evidence. Provide that experiment. Write that code properly.
Please, EM Smith, with an invitation, also post on Climate Audit and publish elsewhere. The official-government hand is in the till and the propaganda is orchestrated — beginning with a 13 million-strong email list.
tallbloke (00:15:37) :
Horace (18:01:45) :
. . . and Steig et al said they relied only a tiny bit on the AWS’s?
Since the Steig et al paper depends on the satellite data, and the data series comes from 3 seperate satellites carrying three different instruments, I wonder if Steig et al have any of the concerns they and others have mooted about UAH and RSS temperature records with regard to orbital drift, clibration etc.
After all, the back extrapolation of the satellite data to a theoretical temporal data point as far distant prior to the start of the record as the length of the record itself is going to amplify any error quite a lot.
. . .
Also, since Steig and Gavin claimed that the AWS data was not used in the reconstruction, why would the bad data affect the outcome at all? And why was Steve McIntyre able to show a graph where the ‘Harry’ Station data *exactly* matches the reconstruction from the satellite data?
Tall –
Amen.
My limited understanding is that the temps from the manned stations and the AWS’s were compared with the satellite IR readings for the same periods, and then those satellite readings were “calibrated” with the actual readings obtained. The calibrated satellite readings were then used to project data from areas with no actual temp readings.
If the stations exhibited a warm site bias at the time of “calibration,” either from burial by snow or Antarctic Heat Island effect, then the newly obtained data would be skewed to the warm as well.
No scientist here, so if my understanding is incorrect please let me know.
Thanks,
H
On co-variance matrices and the data reconstructed by Steig:
papertiger (01:18:08) :
Did you get that? In English –
It’s an unnecessarily complex mathematical expression …
It may be complex, but I don’t think it’s unnecessary or inappropriate. However,
… created to mask the prejudices of the author from reveiw.
…
Here’s the nut of the thing.
Prof X can’t say “We didn’t use Harry” and ” the AWS data are used only for calculating the co-variance matrices used in the different reconstructions.”
These two statements are contradictory.
If they did, in fact, use flawed data, trending high, to generate the covariance matrix, they built in a bias to force all data reconstructed by the matrix to be inaccurately high.
The technique is mathematically sound. Their use of it is completely inappropriate and unjustifiable. I don’t have any way to know whether their behavior is fraud, sloppy thinking, an honest error made because they took the class decades ago, or whatever. But I will assert that they need, at the least, a refresher course in math. And they need to regenerate the matrix, WITHOUT flawed data, reconstruct their data set, and rerun the analysis.
John Philip (02:49:27) :
“RealClimate (Gavin) respond here. Turns out the conclusions of the study are not dependendent on the automated weather station readings”
But, are they dependent on the start date?
Does it matter? From other references i’ve seen it appears the entire study is based on a cherry picked starting date. I believe you have criticized these kind of efforts in the past. Does this mean you now support cherry picking starting dates or will we hear from you later that this entire report is nonsense?
Tim L (20:04:17) :
OT but good
The snake’s enormous dimensions are a sign that temperatures along the equator where the remains were found were once much balmier. (hotter)
“A newly named species from Barbados could be the world’s smallest kind of snake.
Adults of the new threadsnake average only 100 millimeters long (not quite 4 inches), says evolutionary biologist Blair Hedges of Pennsylvania State University in University Park.”
http://www.sciencenews.org/view/generic/id/34803/description/Smallest_known_snake