I’ve recently updated the www.surfacestations.org website with the latest surveys and numbers. We have 534 stations surveyed. Here is where we stand now with USHCN station surveys:
click for a larger image
Climate Reference Network Rating Guide – adopted from NCDC Climate Reference Network Handbook, 2002, specifications for siting (section 2.2.1) of NOAA’s new Climate Reference Network:
Class 1 – Flat and horizontal ground surrounded by a clear surface with a slope below 1/3 (<19deg). Grass/low vegetation ground cover <10 centimeters high. Sensors located at least 100 meters from artificial heating or reflecting surfaces, such as buildings, concrete surfaces, and parking lots. Far from large bodies of water, except if it is representative of the area, and then located at least 100 meters away. No shading when the sun elevation >3 degrees.
Class 2 – Same as Class 1 with the following differences. Surrounding Vegetation <25 centimeters. No artificial heating sources within 30m. No shading for a sun elevation >5deg.
Class 3 (error ~1C) – Same as Class 2, except no artificial heating sources within 10 meters.
Class 4 (error >~= 2C) – Artificial heating sources <10 meters.
Class 5 (error >~= 5C) – Temperature sensor located next to/above an artificial heating source, such a building, roof top, parking lot, or concrete surface.”
During the next week, I plan to add a number of stations during my road trip, and Russ Steele is getting many also on his 3 month cross country road trip through the USA by mobile home.
If you are planning trips this summer, why not check out which stations have been surveyed here and see if any at the bottom of the list that have not been surveyed will be near your travels? We still have over 600 stations to go, and your help is needed!
Well, using the minimum bias estimates:
CRN1 & 2: +0°C
CRN3: +1°C
CRN4: +2°C
CRN5: +5°C
The grand total is an average warm bias of 1.95°C per station.
I do not see any reference to altitude as a condition nor is there any condition for the sea breeze effect which can effect temperatures inland up to a couple of miles.
So wait a second here. I’m no rocket scientist but from where I sit are basically estimating the temperature increase and correcting for more than a 2 degree C difference on far more than half of their stations and then declaring an average temperature increase over the course of many decades of 0.7 degrees or so? Am I following the argument correctly?
evan be careful the estimate of error is must likely the max you would see
and not an average. So, for example you might see the 5C error only on TMIN
and you might see it only during certain seasons. also the error can be either a warming bias or a cooling bias
Evan & Steve: there must be a way to represent the sigma these kinds of errors induce in the ‘average’ temperature. I assume this would show how ridiculous sub-degree prognosis is from this database, especially with the added deviation from NASA’s estimated adjustments.
The grand total is an average warm bias of 1.95°C per station.
no.
those numbers represent a POSSIBLE MAXIMUM error.
i overed Anthony my help in getting that graph correct, but he doesn t sem to be interested.
REPLY: So that “sod” could get a personal handle on station bias, I offered to help him survey some stations, but he didn’t seem to be interested. Too busy blogging on Iraq I guess. There’s no graph here to get “correct”, since the scheme is from NOAA referenced above. Also, my policy is not to pay much attention to anonymous phantoms, such as yourself. If you want respect, put your name to your work.
Am I following the argument correctly?
Oh, yes.
As St. Mac would say, a mining outfit attempting to make such an assay would be up on charges.
However, it is important to point out that the warm bias (offset) is 1.95°C, not the delta (trend). Now most of those violations occurred after 1980 (exurban creep, MMTS conversion etc.), so a fair chunk of the delta is very likely to be a false result.
My guess is that about half or so of the increase in temperature measurements since 1980 is spurious, and that the actual world temperatures are roughly equivalent of the 1930s. I base this guess on:
a.) the site violation issues. We have seen the pics and we have also seen the jumps in the graphs as the microsite conditions near the stations has changed.
b.) such an adjustment would bring temperature correlations very close to the Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation cycles.
those numbers represent a POSSIBLE MAXIMUM error.
Those are the “estimated” (NOAA’s phraseology) MINIMUM error. (All “plusses” are excluded from the calculation.
Furthermore, the errors associated with heat sink primarily manifest themselves at T-Max and T-Min (especially the latter). And how does the USHCN tally their temps? By averaging T-Max and T-Min.
those numbers represent a POSSIBLE MAXIMUM error.
Those are the “estimated” (NOAA’s phraseology) MINIMUM error. (All “plusses” are excluded from the calculation.)
Furthermore, the errors associated with heat sink primarily manifest themselves at T-Max and T-Min (especially the latter). And how does the USHCN tally their temps? By averaging T-Max and T-Min.
and you might see it only during certain seasons. also the error can be either a warming bias or a cooling bias
There are possible cooling biases in the CRN2 category. But in the CRN3 through 5 cats, the bias parameters (waste heat and heat sink factors) are exclusively warming.
And as I said before, T-Max and T-Min (factored, of course, for TOBS) are the only relevant issues insofar as temperature measurement is concerned. Seasonal issues are relevant, though, and NOAA does not seasonally differentiate for their error estimates. (One would assume they were maximized in summer, minimized in winter, and the estimates are for the average.)
I want to re-emphasize that the word NOAA uses for these bias figures are “estimated”, not “maximum”.
CRN4 bias is 2 degrees C OR MORE. And CRN5 is 5 degrees C OR MORE.
And I note that the Rev is VERY conservative when rating the stations, overlooking many of the warming biases, always erring AGAINST warming. So the actual situation may be even worse than the Revs observations.
I do not see any reference to altitude as a condition nor is there any condition for the sea breeze effect which can effect temperatures inland up to a couple of miles.
“Far from large bodies of water, except if it is representative of the area” would seem to cover this contingency.
With only 13% of surveyed stations in in the CRN 1/2 categories, and assuming this remains representative of the whole set, we may be able to get an alternative gridded US average T sometime soon without having to fudge the numbers like NASA.
Will it match GISS?
Is it too late to worry about?
The problem is that most of those CRN1 & 2 stations are in the west coast, which is one area of the country that has seen real warming. They are not well distributed enough to create a reasonable grid.
This may change as the interior of the country is observed.
The new NOAA/CRN network (whenever they actually start it up) is supposed to address this problem.
I believe that Evan is correct in his numbers. I have failed in that I have been unable to travel here in Alabama and many of our stations particularly in the north of the state where I live haven’t been surveyed. Many of these are old stations and would represent a good study. I hope conditions here change in the near future as I have grand children that I \would like to get interested in doing this sort of work/research.
Theratings are shown at the top of the post and the network is in trouble.
13% of the surveyed stations have no bias = 0C
18% of the surveyed stations have minor bias = 2C
13% of the surveyed stations have major bias >= 5C
All of the bias descriptions given in class 3,4,and 5 are warming bias. By this survey it indicates thus far that 87% of the stations have a minimum of 1C bias and that the vast majority of the stations 67% have a bias greater than 2C. For these reasons I believe that Evan is correct in his reasoning.
Tom
sea breeze and altitude are natural conditions and not bias. The argument is that the rise in temperature is man made but if you are measuring the direct waste heat of man that isn’t an accurate measure of the regional or global temperature. That is the reasoning behind the class 3, 4, and 5 classifications, the nearness to direct man made waste heat or man made multipliers of natural heat (walls, asphalt or concrete or other unnatural surfaces nearby.
At least this is my interpretation of what I am reading, if I am incorrect please correct me.
Bill Derryberry
sod, you should note that even if the estimates are exaggerated by a factor of, say, three, they would still be highly significant.
I must correct myself,
13% no bias
18% minor bias 1C
56% moderate bias >= 2C
13% major bias >= 5C
my not reading my on notes.
The network is in trouble.
Bill Derryberry
Anthony – why not just plot graphs of the CRN1 & 2 stations and see how that compares to the official figures?
Evan says they are mainly on the West Coast, but looking at your map, they seem to be quite well distributed
– anyway plotting them would still give some interesting results
– you could also plot the CRN5 stations – and see how they compare to the good ones
Looking at the map, I see hardly any CRN2 stations at all. I think they are largely lost in the west coast sea of red.
The non-coastal south and Southwest (where actual cooling occurred seem under-represented.
Of course, if some sort of gridding procedure could be accomplished, that would give us a reasonable answer. (The CRN network is supposed to do this.)
Evan: “Far from large bodies of water, except if it is representative of the area” would seem to cover this contingency.
However, the Class 1 definition stipulates “at least 100 meters away”. Seabreezes can effect surface temperature up to a couple of miles inland depending on their strength that particular day. When the wind blows off shore, there is no seabreeze effect and the temperatures are very close to the inland temps. Without charting the diffference in number of days of each, your temp readings are not going to reflect a true read for the area. Also, is there a consideration for the temperature of the water over which the wind blows? Early spring Gulf water temps along the central west coast of Florida are generally in the upper 60’s so that seabreeze will effect the area much more at that time of year as opposed to summer when air temps are in the 90’s and water temps are in the high 80’s. It also works in reverse during winter. Gulf water temps are in the lower 60’s/upper 50’s. When a strong cold front blows down from the northwest over the water inland temps may hit the middle 30’s but the coast stays in the 40’s/50’s. If the cold front blows from the north or north east than the wind does not blow over the water and the coastal areas just as cold as inland (except for immediately next to the water).
Just wondering if all this is considered.
well Evan, I would beg to differ. There isnt a qualitative study to back up the bias figures, so that is what we are undertaking. I take the ratings exactly as Dr. LeRoy proposed them, as estimates. Now in the first CRN study a CRN site ( class1)
was compared to a class 2 site ( ASOS) and the effects of site exposure were found to be on the order of .25C. This effect was modulated by winds and clouds. Simply, on some days you might see a .25C difference on cloudy or windy days you might see something different. So take a site. Assume a
FLAT temperature trend for 25 years. 0 trend. Now, introduce a .25C bias
sometime in its history. So, it goes from 0C to .25C, sometime in its history.
but only on certain days and during certain seasons. Now calculate the trend A bias will impact trend estimates when the trend is calculated over
the period when the bias was introduced. Afterwards, the bias does not impact the trend estimate. So, imagine a site that is class 1 in 1975
from 1975 to 1987 it shows no trend. In fact, its always the same temp 14C.
What’s the trend? ZERO. Now suppose in 1988 we introduce a BIAS of 1C.
And the site reads 15 C. and it reads 15C from 1988 to 2008. What the trend
from 1988 to today? ZERO. whats the trend from 1975 to 2008? about .04C per year. So Bias effects trend estimates when the period for which the trend is calculated extends over the change point caused by the bias. That is why it is important to document the time of the changes. Also, the effect of the bias on trend is a function of the length of the trend. Take a 100 year record with zero trend. Introduce a 5C bias step at year 50. Now calculate trends. Trends ending before the bias step will be zero. Trends starting after the bias step will be zero, trends that straddle the step will be effected
Finally, When I compared the class 5 sites to the Class 1 & 2 sites I found differences in trend. Thats what you look for. But you dont see anything close to 5C differences in absolute temps. Why? because the bias signal is not constant
Lets just take the effect of concrete. When a site is over concrete the daily TMAX may actually get depressed because the concrete is a great heak sink.
But when the sun goes down, then the TMIN spikes. Lets say it spikes by 5C
( you can see figures like this in vegas and Reno)
Now calculate the TMEAN for the day ( TMIN+TMAX)/2
So, TMIN has spiked by 5C over what it would normally be, a 5C error, but
TMAX is not effected or is actually a bit cooler in some instances.
So, the error in TMEAN will be 2.5C. And this only on sunny days where the concrete is exposed ( no shading, ect)
Same with AC units and other artifical sources of heat. Sometime they cause a bias, other times not. That is the reason why you should not site near them.
It makes the analysis of the data unfathomably complex.
Finding and quantifying microsite bias will be a very tough but very important piece of work.
I looks like there isn’t much left in Florida for me to offer to help with this summer. Or am I wrong? If there are any left, tell Tom (who I presume is the main surveyor in FL) to save some for the rest of us! 🙂
REPLY: maybe it is time to exapnd and get GISS stations that are not part of USHCN, there are a number of those in Florida, would you like to try those?
Ok, boarding the plane in 45 mins, using airport WiFi. Any new comments will not get approved until tonight, late.
timetochooseagain,
If by Tom you are referring to me, I have done no surveys. As you noticed there isn’t much left in Florida to survey but I would like to take up Anthony’s offer to look at GISS stations that are not part of USHCN. Anthony, were do I find the list and the locations? I found this site via Junkscience.com and the “How not to measure temperature” articles made so much sense even though I have no technical skill in that area. Over the past months I have gathered a general understanding of the processes and terminology by reading the articles and the corresponding comments section.
REPLY: See list of stations at http://www.surfacestations.org that are USHCN
for GISS see this list:
http://data.giss.nasa.gov/gistemp/station_data/
and click on Florida
locate accurate lat/lon and location description at NCDC MMS
http://mi3.ncdc.noaa.gov/mi3qry/login.cfm and use guest login.
Then enter station names from GISS
Slightly off topic but the BBC explain here what really happened with the Roger Harrabin email fiasco.
http://news.bbc.co.uk/player/nol/newsid_7350000/newsid_7355700/7355760.stm?bw=bb&mp=wm&news=1&ms3=6&ms_javascript=true&bbcws=2
Anthony,
Just a thought – If you can’t get enough USCHN sites with CRN1 or CRN2 classifications to set up a credible temp grid across the U.S., what if you use some GISS sites to fill in the gaps and find CRN1 and CRN2 sites and have your volunteers evaluate the sites if it’s easier for them than to hunt down than the USCHN sites? Does that corrupt the whole surfacestations effort?
REPLY: Interesting idea, I’ll give it thought
Tom: Yes, I know about the effects of water. But CRN1 also stipulates “unless it is representative of the area”. That would have to be determined by site. The SHAP adjustment would be expected to adjust for the offset if a station is moved. (But all too often, SHAP fails to do this.)
Finally, When I compared the class 5 sites to the Class 1 & 2 sites I found differences in trend. Thats what you look for.
Yes, LaDochy et al (12/2007) points this out.
But you dont see anything close to 5C differences in absolute temps. Why? because the bias signal is not constant
Only T-Max and T-Min are accounted for. Other times are not taken into account at all. So only Max and Min times are relevant.
Lets just take the effect of concrete. When a site is over concrete the daily TMAX may actually get depressed because the concrete is a great heat sink.
But when the sun goes down, then the TMIN spikes.
La Dochy claims the trend (sic) in urbanized areas concrete does indeed exaggerate T-Max trend (sic), but far more so at T-Min.
The twofold problem is to factor out the offset so it will not become “part of the trend”, and the heat sink trend change as well.
There are large differences in albedo between different paving materials, which change substantially as the materials weather over time. Fresh asphalt has a very low albedo, Fresh concrete made from portland cement has a very high albedo.
Local effects on temperatures are of the order of 5C between different paving materials. That’s an order of magnitude larger than the claimed warming.
http://www.pavement.com/Downloads/RT/RT3.05.pdf
I’d say that the presence of a nearby manmade surface, should automatically exclude a station from consideration in determining temperature trends.
Bah! looks like somebody already surveyed your Fayetteville Arkansas station, i was pondering doing that. Ive passed it probably a dozen times going to work and school. I swear you can see it from the interstate. What kept stopping me was the whole its behind a massive barbed wire fence that surrounds the agriculture test facility they have going on there. They probably wouldnt like me poking around there. And hunting somebody down to ask is such a pain…haha.
The BBC caving to environmentalists? Come on, they have a fine reputation of balanced reporting. Like CBS.
There isnt a qualitative study to back up the bias figures, so that is what we are undertaking. I take the ratings exactly as Dr. LeRoy proposed them, as estimates.
The CRN “estimates” are based on the results of a French study. The Rev has posted the link, but, foolishly, I have not yet captured it.
The CRN handbook was approved in late 2002, so it would not be a particularly recent study.
An up to date look would definitely seem in order on light of the surface stations flap.
Note two post-1980 factors:
–The MMTS conversion. That created a majority of the CRN4 violations. (Many may well have been CRN3 prior to that, but it is usually impossible to say.)
–The air conditioning revolution (a favorite feature in surface station pics).
And of course there was a huge amount of exurban creep during this time that swallowed up who knows how many of the stations.
A portion of those offsets will probably have found their way into the record.
Also consider that heat sinks exaggerate trends, either up or down (LaDochy 12/2007 notes how the latest warm trend was exaggerated in California), and there was a genuine warming trend from 1980 – 1998.
LaDochy also says UHI exaggerates T-Max, but nit as much as T-Min.
Those are the “estimated” (NOAA’s phraseology) MINIMUM error. (All “plusses” are excluded from the calculation.)
again, this is total nonsense.
the source of the calssification can be found here:
http://tinyurl.com/4zcky9
in Leroy’s article “Classification d’un site”
if Leroy was speaking about a minimum error, a site above a parking space (obviously cat V) would show a +5° error even when the surface was covered with snow. this doesnt make any sense.
even regulars here do NOT understand the classification scheme. this happens, because the presentation is misleading.
hm.
REPLY: You are confusing single temperature events with averages for a site. When the snow melts in the parking space, it is back to + bias for the rest of the year. Bottom line, a CRN site by its description and biases listed will be warmer in the long term average, even though events like snow, ice, or an attack on the MMTS by a Slushee machine may change that temporarily. Prove it won’t be on the long term average for station as described by NOAA’s standard as CRN5.
This system is good enough for NOAA to use for the new Climate Reference Network, so complain to them. In fact why not write a letter to Dr. Thomas Karl at NCDC, who signed of on it, and tell him just how flawed you think the system they use is…ooops that would require you to put your real name to paper. Can’t have that.
Purely anecdotal and for the contemporary record.
Raw data for SEATAC to April 17, 2008, it has been cold out here.
From NOAA, at SEA-TAC, the following are monthly departure averages from the current record as of 4-18-08 -/+ 0.1 degrees F. I didn’t use a calculator.
These notes are contemporaneous.
November 07: -0.5
December 07: -0.67
January 08: -2.00
February 08: +1.00
March 08: -2.50
April 08 to date (17): -2.15
It snowed again today in Tacoma. It has never done this in the most recent 16 years I have lived in the NW. In fact, the latest snow in those 16 years was in February. To see this month claimed to be one of the hottest is beyond the pale. This is not just a local anomoly.
I am convinced raw temperature data may forever become non recoverable, even on the internet. Thus I am doing my little part here.
Of course, I may be wrong.
You are confusing single temperature events with averages for a site. When the snow melts in the parking space, it is back to + bias for the rest of the year.
i don t confuse that. i was simply pointing out that the number given is NOT a minimum error. if it was a minimum number, it would happen under all conditions, even when snow is covering the concrete…
REPLY: It is open ended, the error may be greater than or equal to, and we’ve seen examples of CRN5 stations (like Baltimore) than show this.
This system is good enough for NOAA to use for the new Climate Reference Network, so complain to them.
the system of station clasiification is fine. i don t have any complaints about it.
but i do disagree with the way you represent it on this page!
Leroy makes it perfectly clear that the numbers are an estimate, by adding a question mark behind the temperature number. “Classe 3 (erreur 1 °C ?)” (pdf page 6)
REPLY: Well perhaps a ~ (approximate) would be appropriate if that’s your whole argument. I’ll add the ~, not that it will make any difference to how the project is carried out.
http://tinyurl.com/44tbnp
the NOAA paper states, “The errors for the different classes are estimated values.”
both papers are written for proffesionals. non of them would draw the false conclusions from this notation of error estimates, that your readers do. (minimum error…)
so you should provide MORE information on them, but you actually give less than your sources.
final point: of course a class V station will give higher temperatures than one of class I.
but the effect will be far from 5°C. (Steven Mosher has it about right above)
REPLY: Well our experience looking at stations shows that there are errors that large or larger, so we’re good to go. Again go survey some and see for yourself.
actually this rather nice paper by LaDochy gives 0.5° (factor 10 smaller) as a reasonable estimate of the real difference.
http://ams.confex.com/ams/pdfpapers/119064.pdf
Evan and Bill,
Thanks for taking the time to address some of my statements. I know they are entry level but it helps the learning process for us less than technical folks.
Jerry Magnan: Yes, that sound like a good idea.
Is there a down loadable list of stations? Also is there survey instructions?
sod, to be clear, my assumption is that the Leroy study indicates the average error.
Thus:
Classe 1
Classe 2
Classe 3 (erreur 1 °C)
Classe 4 (erreur 2 °C ou plus)
Classe 5 (erreur 5 °C ou plus)
(Sounds so much better in French.)
To be clear, when I said I was using the minimum estimates, what I meant I was excluding the “ou plus” from the calculations.
From what we know of heat sinks, their effect is most noticeable at T-Max and T-Min (esp. the latter). If the US did an hourly average, rather than a straight average of T-Max and T-Min, there would be a decreased potential for error.
actually this rather nice paper by LaDochy gives 0.5° (factor 10 smaller) as a reasonable estimate of the real difference.
Unfortunately the two sites being compared are both smack in the middle of downtown LA (if I read this correctly). Yes, one site has better microsite creds, but they are both masked by UHI.
Firthermore, even in his December 2007 study, LaDochy does not address microsite issues, but only UHI effect.
Needless to add, if rural stations are compromised by microsite violations, any UHI estimate that is based on them is bound to be severely lowballed.
The infamous Baltimore site the Rev posted earlier shows a much greater urban warming offset (+8°C IRRC).
After reading the last several posts (showing at the time I write this), I am going to go out on a limb and ask: Are we now not seeing the forest because of the trees? Wasn’t the intent of the Surfacestation surveys to show that Hansen and the others were using suspect data to push their AGW views? Hasn’t Anthony shown this already and with each and every station that is in conflict with their own criteria for data collection just another nail in their coffin? Hasn’t Anthony’s work already made Hansen adjust his “findings”? Does it matter if the bias are estimates or appoximations? Or if the bias is 0.5 or 0.7 or whatever number that can be derived by manipuating the data? The sad fact is that Hansen is using GIGO to sway opinion and influence government officials who then pass legislation based on unclear and unproven principles to the detriment of us all. When the master blowhard of the universe, Sir Albert Gore, pitched his boogeyman to children and then declared the debate to be over, huge red flags should have gone up in everyone’s head. I am glad Anthony saw them.
Thanks for taking the time to address some of my statements. I know they are entry level but it helps the learning process for us less than technical folks.
I am a less technical folk. And I am trying to boil the arguments and factors down to language that anyone (including myself) can understand.
For the AGW theory to have even a prayer of holding up, the site violations adduced by the Rev would have to be meaningless. They are demonstrably not meaningless.
As a result, none of it adds up. The other intrusive issue that points out the “not adding up” is the D’Aleo correlation of temperatures with AMO/PDO cycles: If the 1979-1998 warming trend has been exaggerated by a factor of, say, two, the D’Aleo correlation fits even better than D’Aleo has so far indicated.
The “soft spot” seems to be in the comparison of satellite-to-surface measurement. But I do not yet know where that is, though I am trying to find out.
I am new to this, but I don’t notice any qualifications in the classification scheme for:
1. Maintanance of whitewash or paint on shelters (this would impact temperature of course).
2. Aspiration (aspirated instruments show less error in sunshine). Even a well sited instrument will show a higher temperature if it is not aspirated. This creates problems for historical temperatures since earlier instruments were not aspirated. It seems there is a lot to sort out.
Bill D.
Tom,
There are no entry level in the climate change discussion. We are already in climate change. It is good to try to learn all that you can. Then apply what you learn to your daily life and to how you vote if you are part of a democracy. Climate change happens all the time in the past, in the now, and in the future.The question as I see it is how it happens, how much it happens, and how to react to it. My personal feelings are that, A we must continue to study the climate to be able to reliably predict our future needs for survival, B continue to study to determine how/why climate change occurs, C How we react to it should be to prepare and adapt to what ever nature brings because I don’t believe we can change the climate enough to make any difference. We must do what creatures have done for eons. Adapt or become much fewer in number or extinct. I opt for adaptation, the other option is grim.
Bill Derryberry
EJ,
Like you I have started to keep a record of high low and precip here at home. I find that by inversion and other variables our temps are usually 5= 8 degrees different from the official temps taken at the Birmingham airport some 90 miles away. the difference is notable in both summer and winter mostly in the winter as we are most always 5 – 8 cooler here.
Just to let you know that you are not the only one that is beginning to not trust the official temps.
I used to live in Kissimmee Fl. and know that the weather was often adapted by the tourism index. (the better the weather the better the tourism). and that country is all pretty flat and often most dampish. Mostly we didn’t get official temps but TV temps so that may have been the difference. Here in Alabama we get both the official temp and the TV station temp. the official temp is usually different more so than the tv station temp. May have to do with the tarmac at Birmingham Airport.
Bill
Derryberry
Over the last three days in South Everett we got perhaps 10 inches total (between snowing and melting snowing and melting). That’s more than we usually get in two winters combined. And rarely if ever this late.
Here is another way to look at it. If the average bias is 1.95C per STATION.
Then what kind of INCREASE in trend would we see over the past 100 years?
Geta loada this.
According to Yilmaz, et al (2008):
City of Erzurum (a “new developing city” in E. Anatolia [Turkey], alt. c. 1900m).
Mean Temperature differences:
Asphalt/Concrete – soil: +6.5°C
Soil – Grass: +5.3°C
Asphalt/Concrete – grass: +11.79°C
Mean Temperature differences 2 meters above:
2m above Asphalt/Concrete to 2m above soil: +5.22°C
2m above Soil – 2m above Grass: +2.32°C
2m above Asphalt/Concrete – 2m above grass: +7.54°C
http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf
I think that pretty much bears out the CRN ratings. And then some! Certainly an eye-opener.
Here is another way to look at it. If the average bias is 1.95C per STATION.
Then what kind of INCREASE in trend would we see over the past 100 years?
Oh, I totally agree that is the correct question. That is exactly why I keep banging on the fact that most of these-here site violations have occurred since 1980.
To wit:
–The MMTS switchover (which is why there are so many CRN4 violations).
–The air conditioning revolution.
–The massive post-1980 exurban creep.
As I have said previously, my guess is that the increase from 1979 – 1998 has been exaggerated about twofold. (Or, very roughly, 0.3°C.) This would put current temperatures at about the mid 1930s level and would match up (even) better with Joe D’Aleo’s PDO/AMO correlations.
Here in Alabama we get both the official temp and the TV station temp. the official temp is usually different more so than the tv station temp. May have to do with the tarmac at Birmingham Airport.
Hmmm. Funny you should say that.
I happen to know a temperature-reader from Alabama.
Let me bite my tongue and merely comment that in my opinion it would be preferable if temperatures were measured using a strictly automated system, and that the results were immediately and automatically transmitted to the NOAA.
I’m not sayin’ anything. I’m just sayin’ . . .
evan, you wrote
“As I have said previously, my guess is that the increase from 1979 – 1998 has been exaggerated about twofold. (Or, very roughly, 0.3°C.)”
now read your first post, where you say the average bias is 1.95C.
do you see the problem? A CRN5 may very well have a 5C bias, on some days
in some conditions, at some times. When you look at the bias over time,
you’ll find that the average is small, more on the order of .3C as you point out.
looking at data and cruching all the numbers for class5 I found it to be something like .15. When we get more class5 data, I’ll do those calculations and share them
[…] Stations Update Surfacestations Update Watts Up With That? 534 of the USHCN surface stations have now been surveyed, leaving 684 left to go. Yours truly just […]
do you see the problem?
I see what you are saying, but you need to see more carefully what I was saying. I have addressed this problem.
Read again. Thus,
OFFSET = +1.95°C
TREND ~ +o.3°C
Please note I have been quite careful to make this crucial differential between offset and trend.
As for the validity of LeRoy’s offset measurement:
Observe also the Yilmaz study.
There are a couple of qualifications:
On the one hand:
-Yilmaz took the measurements during August, and the effects are presumably at a maximum at that time of year
On the other hand:
-These are 24-hour averages including both day and night.
-The measurements are 2m aboveground and the MMTS sensors are considerably closer to the ground than that.
-The difference would likely be even greater except that it is masked by UHI.
The difference at ground level between asphalt/concrete and grass: 11.79°C
The difference at two meters between asphalt/concrete and grass: 7.54°C
Seems to me that a year-round average at c. 4 feet over ground level would clock in right around 5°C. And a LOT more at some of the more outrageous sites that are a HECK of a lot worse than merely being located above concrete or asphalt.
And, in closing, even if the difference in trend turns out to be as low as 0.15C, which is possible, though I doubt it considering LaDochy (Dec. 2008), it is still quite significant in the scope of post-1980 warming measurements. It would, in fact, knock the top right off the crisis.
FWIW, I agree that there has been warming since 1980, for PDO/AMO effect, if nothing else. But the degree of warming is quite critical in the overall debate. I suspect that the trend has been exaggerated both by classic heat sink effect and by spurious introduced warming offset that has not been accounted for by SHAP.
If I had known about this listing of un-surveyed stations, I could have done a couple this past weekend. I drove from Va through Johnstown Pa, Ridgeway, and ended up in Warren Pa. Those 3 are not done yet. There are a couple near me. Who do I send the images, etc too?
REPLY: See sign up info at http://www.surfacestations.org and signup there to submit to the online database. The list is linked at the top of the page
REPLY: Well perhaps a ~ (approximate) would be appropriate if that’s your whole argument. I’ll add the ~, not that it will make any difference to how the project is carried out.
i think simply adding the phrase “temperature numbers are an estimate” would be a good start.
adding that those numbers are talking about potential MAXIMUM errors would be even better.
but i still would simply imterested in your view on this. what will the difference between the “average” type V and Type I station be (over the year!), according to your opinion?
Seems to me that a year-round average at c. 4 feet over ground level would clock in right around 5°C. And a LOT more at some of the more outrageous sites that are a HECK of a lot worse than merely being located above concrete or asphalt.
evan jones, you are pulling the “Phoenix arizona” trick again.
i wasn t very suprised to see an example in Turkey coming up.
i doubt that you will find many stations that are worse than:
* turkey like temperature
* full concrete surface
* no shadow
AND you have only looked at 15 windless august days…
but i am looking forward to pictures, showing worse stations, that fullfill the conditions above…
evan , OFFSET creates a trend.
.15C is important. But claiming that the average bias error is 1.95C is wrong
and diminishes the credibility of this effort.
The bias error will be DETERMINED by objective comparisons. Not Leroys
subjective estimation.
Yes, the offset can create a trend but only if the entire offset was there to begin with. If it started out as CRN3 and then moved up to CRN4 with the MMTS switchover, there would not be the full CRN4 offset added to the trend.
But I be the offset is that big. Check out that Yilmaz study.
http://www.ejournal.unam.mx/atm/Vol21-2/ATM002100202.pdf
Yeah, I bet that offset number is correct. Remember, some of the offset will (presumably) be corrected by SHAP. (Not necessarily, of course, but that IS what SHAP is FOR!)
I recognize we are on the same track, here: IT HAS TO ADD UP!
i doubt that you will find many stations that are worse than: . . .
Heck, the effects are probably masked and muted by UHI. They could even be worse.
And “full concrete surface” is moot. Those US stations are all too often swimming in concrete oceans, even when located in Squeedunk, Montana.
Besides, Anthony doesn’t even rate most stations perched on Parking Lot Paradise as CRN5. He is very, very conservative as to his ratings. You will notice that everyone has been griping at the LeRoy estimates (confirmed, so far, both by Yilmaz and the “HOT-L Baltimore” observations). They have NOT been griping that the Rev has been exaggerating when making his ratings!
And I have no objections whatever if others experiment on this further. In fact, I heartily encourage it. The more, the merrier.
adding that those numbers are talking about potential MAXIMUM errors would be even better.
Where does it say “maximum”? From what i can tell, it only says, “estimated”. And it seems the estimations may have been pretty dead-on.
And “full concrete surface” is moot. Those US stations are all too often swimming in concrete oceans, even when located in Squeedunk, Montana.
not a single one of the “bad” stations on the first page of posts on this blog fullfils the “full concrete, no shade” criteria. (and i guess some of the places are colder than turkey..)
i am curious. any picture of a station, that you think qualifies?
Where does it say “maximum”? From what i can tell, it only says, “estimated”. And it seems the estimations may have been pretty dead-on.
again, a station that is type V because of concrete surface, will NOT show an error “bigger than 5°” during winter, when the concrete is covered with snow.
it can t be an average or minimum error, that leaves max error.
just look at page 142 of the Turkey paper:
“minimum at 06:00 with 3.35°C“
and that is on a windless august day in Turkey…
i am curious. any picture of a station, that you think qualifies?
I’m not sure that the shade from a honking heat sink counts as a cooling bias
it can t be an average or minimum error, that leaves max error.
It can’t be an average error because . . . ?
The Yilmaz studies use 24-hour averages. If only TMax and TMin were used (as they are in US stations), the difference would have been even greater.
But, yes, I would LOVE to see the experiment done year ’round with the height at 1.5 Meter above rather than 2, with separate data for TMax and TMin average (which is how US temps are taken). Also in a rural setting so the differences are not masked by UHI. (Also perhaps at a lower altitude.)
You are twisting in the aspirator on this one, I’m afraid. We are NOT talking a half-degree difference, here!
I’m not sure that the shade from a honking heat sink counts as a cooling bias
neither do i. but neither is a paved walkway the same as a LANDING STRIP!
It can’t be an average error because . . . ?
because if the average on windless sunny august days in TURKEY (on a landing strip, compared to grass) is 7.5°C, then even the yearly average in Turkey won t make 5°C.
i am still waiting for an alaskan type 5 station showing a 5°C variation because of pavement over winter…
If only TMax and TMin were used (as they are in US stations), the difference would have been even greater.
no.
11.7°C+3.3°C=15°C
that would give exactly the 7.5°C that the hour average gives. (both are pretty good estimates of the real daily mean. that is why they are both used for this purpose…)
But, yes, I would LOVE to see the experiment done year ’round with the height at 1.5 Meter above rather than 2,
looking at the data from ground temperature and 2m, i don t expect a major difference for 1.5m.
You are twisting in the aspirator on this one, I’m afraid. We are NOT talking a half-degree difference, here!
i m not sure about this, in this extreme case. (extreme temperature, extreme environment differences.) and as you, i d like to see more data.
but for real stations, the 0.5°C are a FACT, as shown by LaDochy.
oops, my fault. the numbers above are for min/max difference, not temperature. saw the numbers and thought i could skip some calculations…
again: lowest temp 5:00 14.5°C- 10°C=4.5°C
highest temp:38,5-27.0°C= 11.5°C
so min max would give 8°C difference between AC and grass instead of 7.5°
feel free to correct those numbers (pretty tired still, should go and get some sleep..)
Seems about right.
And I agree that it is not the offset that is at issue (unless it gets conflated into the record on account of bad SHAP). It is the trend change that matters.
But heat sinks affect the rate of change as well.
LaDochy, Medina, Patzert. 2007. Recent California climate variability: spatial and temporal patterns in temperature trends. Climate Research, 33
http://www.int-res.com/abstracts/cr/v33/n2/p159-169/
I also acknowledge that this works both ways: a cooling phase would undo itself at the same faster rate it followed “on the way up”.
But FILENET freaks me out. It means that UHI gets calculated off of sites that may well be running ‘way too hot.
I am suggesting that the increase in temps from 1980-1998 may be only around half of what has been measured (roughly a 0.3C or so difference in trend).
I will add, though, that a lot of the surface stations are located in airports on landing strips. I don’t believe the Rev rates them as CRN5, though. He is very careful not to exaggerate the biases (if he did, his critics would come down on him like a ton of bricks).
I would like to see a Yilmaz-type study be done year-round under all conditions. (I also wonder how the almost 2000m altitude affects the findings.)
The LaDochy comparison you cite occurs under LA UHI and neither station looks good, judging by the pictures. And, yes, I think the issue needs to be carefully studied both for offest and for trend.
nice exchange of thoughts. thanks.
You’re welcome. I don’t deny there has been some warming, and neither do do I deny man’s hands are clean.
The whys and wherefores are important, especially as we have to base policy (or lack of policy) on the answers.
trong>REPLY: Getting better, thanks. Aleves are my friends.