The long awaited surfacestations paper

This summary is from Dr. Pielke at the University of Colorado in his words. I’ll have my own post on some detail not covered here, with links to the SI – data code, etc we are preparing in a day or two. Some may ask why I am not lead author. That was my choice, because the strength is in the statistical analysis, and I wanted it clear that the paper is about that joint work and not about any one person’s efforts. – Anthony

UPDATE: Also, two other posts, by co-author Dr. John Nielsen-Gammon that are must reads are:

The surfacestations paper – statistics primer

Something for Everyone: Fall et al. 2011

Guest post by Dr. Roger Pielke Sr.

A Summary Of Our New Paper “Analysis Of The Impacts Of Station Exposure On The U.S. Historical Climatology Network Temperatures and Temperature Trends” By Fall Et Al 2011

 Our paper

Fall, S., A. Watts, J. Nielsen-Gammon, E. Jones, D. Niyogi, J. Christy, and R.A. Pielke Sr., 2011: Analysis of the impacts of station exposure on the U.S. Historical Climatology Network temperatures and temperature trends. J. Geophys. Res., in press. Copyright (2011) American Geophysical Union.

has been accepted and is now in press. Below I have presented a summary of the study and its major messages from my perspective.  While the other authors of our paper have read and provided input on the information given below, the views presented below are mine. I will be posting on the history of my involvement on this subject in a follow-up post in a few days.

Volunteer Study Finds Station Siting Problems Affect USA Multi-Decadal Surface Temperature Measurements

We found that the poor siting of  a significant number of climate reference sites (USHCN) used by NOAA’s National Climatic Data Center (NCDC) to monitor surface air temperatures has led to inaccuracies and larger uncertainties in the analysis of multi-decadal surface temperature anomalies and trends than assumed by NCDC.

NCDC does recognize that this is an issue. In the past decade, NCDC has established a new network, the Climate Reference Network (CRN), to measure surface air temperatures within the United States going forward. According to our co-author Anthony Watts:

“The fact that NOAA itself has created a new replacement network, the Climate Reference Network, suggests that even they have realized the importance of addressing the uncertainty problem.”

The consequences of this poor siting on their analyses of multi-decadal trends and anomalies up to the present, however, has not been adequately examined by NCDC.

We are seeking to remedy this shortcoming in our study.

The placement of the USHCN sites can certainly affect the temperatures being recorded—both an area of asphalt (which is warmer than the surroundings on a sunny day or irrigated lawns (which is cooler than surrounding bare soil on a sunny day) situated near a station, for example, will influence the recorded surface air temperatures.

NOAA has adopted siting criteria for their climate reference stations: CRN 1 stations are the least likely to being influenced by nearby sources of heat or cooling, while CRN 5 stations are the most likely to be contaminated by local effects.  These local effects include nearby buildings, parking lots, water treatment plants irrigated lawns, and other such local land features.

To determine how the USHCN stations satisfied the CRN siting criteria and also whether the station siting affected temperature trend characteristics, Anthony Watts of IntelliWeather set up the Surface Stations project in 2007. More than 650  volunteers nationwide visually inspected (and rated) 1007 of the 1221 USHCN stations.  The volunteers wrote reports on the surroundings of each station and supplemented these reports with photographs.  Further analysis by Watts and his team used satellite and aerial map measurements to confirm distances between the weather station sensors and nearby land features.

The Surface Stations project is truly an outstanding citizen scientist project under the leadership of Anthony Watts!  The project did not involve federal funding. Indeed, these citizen scientists paid for the page charges for our article.  This is truly an outstanding group of committed volunteers who donated their time and effort on this project!

Analyzing the collected data, as reported in our paper, we found that only 80 of the 1007 sites surveyed in the 1221 station network met the criteria of CRN 1 or CRN 2 sites – those deemed appropriate for measuring climate trends by NCDC.  Of the remaining, 67 sites attained a CRN 5 rating – the worst rating.  While the 30-year and 115-year trends, and all groups of stations, showed warming trends over those periods,  we found that the minimum temperature trends appeared to be overestimated and the maximum warming trends underestimated at the poorer sites.

This discrepancy matters quite a bit. Wintertime minimum temperatures help determine plant hardiness, for example, and summertime minimum temperatures are very important for heat wave mortality. The use of temperature trends from poorly sited climate stations, therefore, introduces an uncertainly in our ability to quantify these key climate  metrics.

While all groups of stations showed warming trends over those periods, there is evidence to suggest a higher level of uncertainty in the trends since it was found, as one example, that according to the best-sited stations, the 24 hour temperature range in the lower 48 states has no century-scale trend, while the poorly sited locations have a significantly smaller diurnal temperature range. This raises a red flag to avoid poorly sited locations since clearly station measurement siting affects the quality of the surface temperature measurements.

The inaccuracies in the maximum and minimum temperature trends do matter also in the quantification of global warming. The inaccuracies of measurements from poorly sited stations are merged with the well sited stations in order to provide area average estimates of surface temperature trends including a global average.  In the United States, where this study was conducted, the biases in maximum and minimum temperature trends are fortuitously of opposite sign, but about the same magnitude, so they cancel each other and the mean trends are not much different from siting class to siting class. This finding needs to be assessed globally to see if this also true more generally.

However, even the best-sited stations may not be accurately measuring trends in temperature or, more generally, in trends in heat content of the air which includes the effect of water vapor trends (which is the more correct metric to assess surface air warming and cooling; see). Also, most of the best sited stations are at airports, which are subject to encroaching urbanization, and/or use a different set of automated equipment designed for aviation meteorology, but not climate monitoring. Additionally, the NCDC corrections for station moves or other inhomogeneities use data from poorly-sited stations for determining adjustments to better-sited stations, thus muddling the cleaner climate data. We are looking at these issues for our follow-on paper.

However, we know from our study that the use of these poorly sited locations in constructing multi-decadal surface temperature trends and anomalies has  introduced an uncertainty in our quantification of the magnitude of how much warming has occurred in the United States during the 20th and early 21st century.

One critical question that needs to be answered now is; does this uncertainty extend to the worldwide surface temperature record? In our paper

Montandon, L.M., S. Fall, R.A. Pielke Sr., and D. Niyogi, 2011: Distribution of landscape types in the Global Historical Climatology Network. Earth Interactions, 15:6, doi: 10.1175/2010EI371

we found that the global average surface temperature may be higher than what has been reported by NCDC and others as a result in the bias in the landscape area where the observing sites are situated. However, we were not able to look at the local siting issue that we have been able to study for the USA in our new paper.

Appendix- Summary of Trend Analysis Results

Temperature trend estimates do indeed vary according to site classification. Assuming trends from the better-sited stations (CRN 1 and CRN 2) are most accurate:

  • Minimum temperature warming trends are overestimated at poorer sites
  • Maximum temperature warming trends are underestimated at poorer sites
  • Mean temperature trends are similar at poorer sites due to the contrasting biases of maximum and minimum trends
  • The trend of the “diurnal temperature range” (the difference between maximum and minimum temperatures) is most strongly dependent on siting quality. For 1979-2008 for example, the magnitude of the linear trend in diurnal temperature range is over twice as large for CRN 1&2 (0.13ºC/decade) as for any of the other CRN classes. For the period 1895-2009, the adjusted CRN 1&2 diurnal temperature range trend is almost exactly zero, while the adjusted CRN 5 diurnal temperature range trend is about -0.5°C/century.
  • Vose and Menne[2004, their Fig. 9] found that a 25-station national network of COOP stations, even if unadjusted and unstratified by siting quality, is sufficient to estimate 30-yr temperature trends to an accuracy of +/- 0.012°C/yr compared to the full COOP network. The statistically significant trend differences found here in the central and eastern United States for CRN 5 stations compared to CRN 1&2 stations, however, are as large (-0.013°C/yr for maximum temperatures, +0.011°C/yr for minimum temperatures) or larger (-0.023°C/yr for diurnal temperature range) than the uncertainty presented by Menne at al (2010).

More detailed results are found in the paper, including analyses for different periods, comparisons of raw and adjusted trends, and comparisons with an independent temperature data set.

Questions and Answers

Q: So is the United States getting warmer?

A: Yes in terms of the surface air temperature record. We looked at 30-year and 115-year trends, and all groups of stations showed warming trends over those periods.

Q: Has the warming rate been overestimated?

A: The minimum temperature rise appears to have been overestimated, but the maximum temperature rise appears to have been underestimated.

Q: Do the differing trend errors in maximum and minimum temperature matter?

A: They matter quite a bit. Wintertime minimum temperatures help determine plant hardiness, for example, and summertime minimum temperatures are very important for heat wave mortality. Moreover, maximum temperature trends are the better indicator of temperature changes in the rest of the atmosphere, since minimum temperature trends are much more a function of height near the ground and are of less value in diagnosing heat changes higher in the atmosphere; e.g see .

Q: What about mean temperature trends?

A: In the United States the biases in maximum and minimum temperature trends are about the same size, so they cancel each other and the mean trends are not much different from siting class to siting class. This finding needs to be assessed globally to see if this also true more generally.

However, even the best-sited stations may not be accurately measuring trends in temperature or, more generally, in trends in heat content of the air which includes the effect of water vapor trends.  Also, most are at airports, are subject to encroaching urbanization, and use a different set of automated equipment. The corrections for station moves or other inhomogeneities use data from poorly-sited stations for determining adjustments to better-sited stations.

Q: What’s next?

A:  We also plan to look specifically at the effects of instrument changes and land use issues, among other things.  The Surface Stations volunteers have provided us with a superb dataset, and we want to learn as much about station quality from it as we can.

================================================================

UPDATE: Since some people seemed unable to divine the link upstream, the pre-print version of the paper, posted on Dr. Pielke’s website is available here:

http://pielkeclimatesci.files.wordpress.com/2011/05/r-3671.pdf

– Anthony

UPDATE2: Dr. John Nielsen-Gammon, Texas State Climatologist and co-author, weighs in with his post:

Something for Everyone: Fall et al. 2011

As you may have heard, the long-awaited peer-reviewed analysis of the results of the SurfaceStations.org project has finally been released. I can’t wait to see the dueling headlines. Some will argue that the take-home message should be: Poor Station Siting Strongly Effects Temperature Trend Measurements, and will laugh at the idea that we can say with sufficient accuracy what has happened to our climate. Others will argue that the take-home message should be: Poor Station Siting Has No Effect on Temperature Trend Measurements, and will laugh at all the effort expended on a null result. Both sides will find solid evidence for their points of view in the paper. How can that be? How can one paper support opposing conclusions?

Here, in brief, are the answers: The poorest sites tend to be warmer. The minimum temperatures are warming faster at poorer sites than at better sites. The maximum temperatures are warming slower at poorer sites than at better sites. The adjustments reduce the differences by about half. The two effects are roughly equal and opposite so the mean temperature is rising at about the same rate across sites of different quality while the diurnal temperature range shows the biggest difference across sites.

On the one hand, this seems to be confirmation of the quality of the temperature record. All types of sites show the same mean temperature trend, so there’s no change necessary to our estimates of observed historical temperature trends in the United States.

On the other hand, there are several warning flags raised by this study. First, station siting is indeed important for the maximum and minimum temperature measurements. Second, the adjustments are only partly correcting the temperature record. Third, since the adjustments use data from all surrounding stations, there’s the danger that the mean trends are dominated by data from the poorer stations. (Less than ten percent of the USHCN stations are sited well enough to be considered appropriate for climate trend measurements.) Finally, and perhaps most important, are we really so lucky that the rest of the world would also have its poorly-sited stations have erroneous maximum and minimum temperature trends that just happen to be equal and opposite to each other?

Read his full essay here

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tonyc

Quick question:
Does the CRN rating take into account potential urban heat island (UHI) effects, or does that just deal with the immediately local site conditions?

Ed Forbes

looking forward to reading your paper
congrats on finally getting it out of review

ShrNfr

Congratulations to all involved.

Theo Goodwin

Could someone give us a backgrounder on the practices of NCDC and NOAA today regarding the recording of temperatures and calculating of trends. Is it the case that they continue to take raw temperature numbers and average them to get daily numbers? If so, which? If so, why? How much of past temperature data is based on averaged numbers? Are trends calculated from averaged numbers?

Anthony,
One of the interesting points in Menne et al 2010 was the suggestion that CRN12 sites had a lower rate of MMTS conversions than CRN345 sites. As MMTS conversions are associated with a strong max cooling bias and a moderate min warming bias, this would seem to account for at least some of the effect you note in your paper.
http://rankexploits.com/musings/2010/a-cooling-bias-due-to-mmts/
Congratulations are in order, by the way. I hope to have a chance to follow in your footsteps at some point in the future 😉
REPLY: We have some ideas on that, and will be discussing it in the upcoming post. – Anthony

Mike

So I guess this is unfortunately a big…
*YAWN*
REPLY: Well given how much time has elapsed from the time of posting to your comment, I can see how you could come to the snap conclusion without any deeper reading comprehension involved. – Anthony

littlepeaks

“1007 of 1221 stations have been examined in the USHCN network.” What happened to the rest?
Also, when published, I hope you will post a link where we can purchase a printed copy of the study.
REPLY: That’s the number of stations that we could positively identify, survey, and that passed quality control. We actually have more stations surveyed since then but at some point your have to stop and move forward. We’ll never get 100% due to some stations being off limits or closed. The hyperlink to the paper (PDF) is in the post, look closely – Anthony

Earle Williams

tonyc,
Probably answers in queue already, but just in case…
CRN is a microsite rating only. It does not address the UHI influence on temperature measuring stations.

OK S.

Congratulations again on your paper. It was your Surface Stations Project that led me to your site in the first place. I used to follow your progress regularly until you had to stop updating it when “someone” stole your preliminary work to publish his own paper.
One question though. Did the whitewash/paint study ever turn up anything useful?
OK S.

Mike

I read the whole post and donated to the paper… FYI
As I see it, the hope was for a classification-dependent over-estimation of the warming effect which doesn’t appear to be happening. The results net out. This would have been a major argument for a UHI-influenced skewing of the US dataset, right? Unfortunately that does not seem to exist, so my YAWN is directed at the (unfortunate) lack of support for this model. It is of course nice to know that the over-estimated mins and under-estimated maxes will help model heat-wave mortality and plant hardiness, but I doubt that result was the hope for this project.
REPLY: Read the paper, the link is in the post above – Anthony

rpielke

tonyc – Thank you for your comment. We just examined immediate siting issues. The other effects on the temperature trends, such as from larger scale landscape (e.g. urban), is an issue that also needs to be combined with the siting issue.

Mike Bromley

It will be interesting to see the responses once the gravity of this is absorbed (unlike the ‘yawn’ posted above).
Once again, congratulations!

John

A question regarding a part of the reportage above on the new paper (and let me add to the congratulations of others to Anthony et al on its publication):
“Q: What about mean temperature trends?
A: In the United States the biases in maximum and minimum temperature trends are about the same size, so they cancel each other and the mean trends are not much different from siting class to siting class….”
This appears to say that although there are errors with important implications for max and min temps, the implications do not include a serious bias in increases in mean temperature.
So my question is, does this mean that the initial testimony by Prof. Muller on the BEST project may be pretty much correct, in that he, too, found increases in mean temperatures that we only a tenth of a degree smaller than the official government version?

“Q: So is the United States getting warmer?
A: Yes in terms of the surface air temperature record. We looked at 30-year and 115-year trends, and all groups of stations showed warming trends over those periods.”

My question is, does this study invalidate the published study of Goodridge 1996? His study was confined to California, and results were grouped by county. It concluded there was zero warming in counties with under 100,000 population; essentially rural counties without urban heat island effects. His study period was approximately 1910 to 1998. However, high-population counties showed a 4 degree F increase in temperature over the study’s time frame.
Also, I found that many cities in the U.S. have experienced essentially zero long-term warming by plotting the data released by Hadley Research Center, their CRUT3. Those cities include:
(source: http://sowellslawblog.blogspot.com/2010/02/usa-cities-hadcrut3-temperatures.html)
Montgomery, Alabama
Fort Smith, Arkansas
Little Rock, Arkansas
Fresno, California
Sacramento, California
West Palm Beach, Florida
Jacksonville, Florida
Key West, Florida
Tampa, Florida
Atlanta, Georgia
Des Moines, Iowa
Boise, Idaho
Pocatello, Idaho
Peoria, Illinois
Evansville, Indiana
Dodge City, Kansas
New Orleans, Louisiana
Shreveport, Louisiana
Caribou, Maine
Marquette, Michigan
Columbia, Missouri
Meridian, Mississippi
Asheville, North Carolina
Cape Hatteras, North Carolina
Raleigh, North Carolina
Winnemucca, Nevada
Buffalo, New York
Dayton, Ohio
Oklahoma City, Oklahoma
Pendleton, Oregon
Portland, Oregon
Pittsburgh, Pennsylvania
Charleston, South Carolina
Greenville, South Carolina
Aberdeen, South Dakota
Rapid City, South Dakota
Chattanooga, Tennessee
Nashville, Tennessee
Abilene, Texas
El Paso, Texas
San Angelo, Texas
San Antonio, Texas
Richmond, Virginia
Madison, Wisconsin
Casper, Wyoming

chip

Congratulations, Anthony!
I know it will be a temptation on some people’s parts to see not too much here, but I also know that academic papers should be cautious things and you have added considerably to the body of knowledge – never a bad thing. Your results have already added new opportunties for study and shown that people outside academic areas of study have something to offer science. Thanks for all your efforts.
Chip

TomRude

As an aside, Let’s notice the worldwide coverage by the MSMedia for the O’Donnell et al. 2011 paper…

upcountrywater

I’m looking forward to a coffee table edition, one with big pictures and graphs…
I’m wondering how many of the stations that recorded a state by state record low, are still alive and recording data?

Congratulations to all the authors. (…nice to see the triumphant Arizona station with its own parking lot permanently committed to the scientific literature…). But more importantly, it is nice to see some careful and un-spun climatological research going on. Thank you for your dedication.

stan

How much influence have the poor sites had on the temperature adjustments made to other sites?

George E. Smith

“”””” Mike says:
May 11, 2011 at 9:45 am
I read the whole post and donated to the paper… FYI
As I see it, the hope was for a classification-dependent over-estimation of the warming effect which doesn’t appear to be happening. The results net out. This would have been a major argument for a UHI-influenced skewing of the US dataset, right? Unfortunately that does not seem to exist, so my YAWN is directed at the (unfortunate) lack of support for this model. It is of course nice to know that the over-estimated mins and under-estimated maxes will help model heat-wave mortality and plant hardiness, but I doubt that result was the hope for this project. “””””
“”””” but I doubt that result was the hope for this project. “””””
So is this how good science is done ? One designs an experiment to prove the validity of some pre-conceived notion ?
I followed the blow by blow revelations of the arrays of barbecue locations, as they were unearthed by Anthony’s mottley volunteer crew. I particularly like the Arizona University example; surely the gold standard of misspent research funds; and so beautifully located right outside the doors of those who are supposed to be experts. That Scientific photograph adorns the entrance to my office cube.
I seem to recall, we all reacted with amazement as the volunteers turned up ever funnier examples of what our tax dollars pay for.
As near as I can discern; the project had no aim; well other than an attempt to log every single station, and let the chips fall where they may.
So Mike; how is it that you were privy to the real intent of this project when Anthony Watts started it. I somehow doubt that Anthony himself knew where it was going; other than to attempt to achieve the above stated objective.
If you do a series of studies to see how far maimed frogs can jump; you will surely find, that if you cut off all four legs, they no longer will jump. Does it matter that you set out to demonstrate that quadraplegic frogs become stone deaf.
I’ll wait to read the published paper, before trying to discern the motives for the project.

Scott

How can one paper support opposing conclusions?

Anyone who asks that question and is serious shows how poor science education currently is. And it’s clear from MSM reports of science too…conclusions are often interpretations, not the data themselves. Much of society goes along with those conclusions and assume they’re facts because it fits with their agenda/politics/worldview. Then they get bent out of shape when a critical thinker comes along and questions stuff…
On another note, congratulations Anthony and everyone else involved!
-Scott

Joseph Murphy

I believe the temp trend in US sites will be fairly consistent with sites around the world. Sites with artificially warming or cooling should not display a significant trend. If you are taking the max temp of a site that is sitting on pavement that heats up 110F everyday then the trend will be zero. Bad station siting should act as a dampener on trend except for the point at which the artificial heating or cooling started affecting the equipment.

Scott

Joseph Murphy says:
May 11, 2011 at 11:20 am
But what if your example site is currently situated on an asphalt parking lot but 60 years was in the middle of a corn field?
-Scott

wayne

Roger Sowell says: May 11, 2011 at 10:08 am

Also, I found that many cities in the U.S. have experienced essentially zero long-term warming by plotting the data released by Hadley Research Center, their CRUT3. Those cities include:
—-
I can only speak of Oklahoma City, it has the main airport on the very south side edge with a mainly southerly prevailing wind most of the year. Nothing but fields to the south. It gives us an “energy shield” so to speak. The only trend I find is in the winter minimum readings when the prevailing wind is northerly. That seems to be why it shows no effect from “global warming”. You might check those other cities and exactly where the airports and stations are in relation to the prevailing wind (if they have one) and watch for the trend reversal between maximum and minimum in relation to the seasons, at least here winter is different than the other three. By that simple observation over the years it seems to answer it all, at least in this one case. If the airport and station was on the north edge all of that would change of course.

Craig F

Mike says…….
After my first reading of the post and comments it’s hardly a *YAWN* as you so eloquently put it.
I must admit to being a little surprised by the initial findings given that I’d have expected a different conclusion regarding the poor sites. But that’s because I wanted a different conclusion. It does nothing to alter the fact that the sites are poor in the US. Most likely are elsewhere ( anyone got a list of UK sites so I can record some? ) and as a result the past global temperature record as noted from surface stations is not to be trusted and a radical rethink of these sites is needed.
Now. On to read the paper.

Scott Covert

Thanks for your hard work Anthony.
Thank you and all the authors for simply stating the results without putting any personal spin or bias. This is what science is supposed to be. Unbiased, open, and fact based.
Your paper adds more information to the debate. It is all wheat and no chaff. Both sides of the AGW debate can use this information without worry over it’s validity.
It may not be a smoking gun but I assume there are none in climate research, just bars of soap carved into gun shapes, covered with shoe polish used to scare the media and the public at large. The Mann Hockey Stick is one such gun, most of the shoe polish is gone from over use and now it only blows bubbles.
REPLY: One of the things we learned is that there are so few well sited stations with long records, and even those have been compromised. There may not even be enough to do meaningful comparisons, but we are doing a follow up paper where we are drilling into the metadata deeper and we may have some additional insight. – Anthony

CRS, Dr.P.H.

The history of science is replete with examples of how citizen-scientists have stood up to the established hierarchy of their time & prevailed. Galileo Galilei, Gregor Mendel and other heroes come to mind.
Congratulations and best wishes to you all, this is an incredibly important development with historic implications.

kuhnkat

SO………
you computed trends based on either raw data from questionably sited stations or on adjusted data based on questionably sited stations and poorly researched adjustments and the trends are supposed to mean something??
Oh yeah, that doesn’t even start to talk about the spatial coverage of the stations or the idea that you can AVERAGE temperatures from disparate elevations, humidity levels…
CO2 is measured at stations where they control for local anthropogenic and natural sources. When are they going to use the same schema for temp background??? In other words, if I am trying to find the average temperature of my house, I am NOT going to site thermometers next to heater ducts or elements, light bulbs and computers on all day…
Are y’all trying for a spot on AR7????

Jeremy

So, how long until the backstory of peer-review obstruction comes out?

Alba

Help!! I seem to be having hallucinations. Last night I thought I read a post on WUWT which claimed that the Vatican was getting involved with the issue of climate change. I thought that I read lost of comments on the post. Then I thought that I put a comment on myself. Duh! When I went to see if my comment had been accepted I found no mention of anything to do with the Vatican. The post I thought I had read just wasn’t there. Is there a cure for thinking that you have read non-existent posts on WUWT?
REPLY: It simply scrolled off the main page, down at the bottom note this:
← Older posts
Click on that or use the search box for “vatican” – Anthony

1DandyTroll

So, essentially, disregarding that you guys just give more proof that climate is poorly manipulated statistics at best, the climate hippies will, of course, just deny it still.
Heck of a job though.

DR

Congratulations, Anthony et al.!
Just one question – Table 1, Class 2, should it be “No artificial heating sources within 30m.” ? (i.e. less than 100m but more than 30m?)

Alec, aka Daffy Duck

Congrats! and.. it went up on DIGITAL JOURNAL 15 minutes ago:
Widespread Flaws in Weather Stations Networks Used to Track National Temperature Trends, Says New Study
Read more: http://www.digitaljournal.com/pr/305726#ixzz1M4cLfrG7

Milwaukee Bob

Congratulations Doc, (and ALL volunteers) on getting your Baby birthed. And a right cute thing IT is!

40 shades of green

Congrats.

Alan

Suggestion/question: would it be possible to block any submissions for comments on a post in, say, the first 15 or 20 minutes of its posting? (Then maybe some people would take the time to read and digest the actual article before reacting often too quickly.)

Engchamp

I was going to say “good post” or something akin.
However, I have been diverted by…
1DandyTroll says:
May 11, 2011 at 12:02 pm
“So, essentially, disregarding that you guys just give more proof that climate is poorly manipulated statistics at best, the climate hippies will, of course, just deny it still.
Heck of a job though.”
I would suggest that comment is one heck of a tautology.

Richard S Courtney

Excellent! Congratulations to all involved.
And, as is usual with the most interesting of studies, the findings are not what anybody could have predicted.
Are the findings typical of sites worldwide? Perhaps and perhaps not, so reason form more study: i.e. another indication of good science.
Thankyou.
Richard

Stephen Brown

I have had insufficient time to read thoroughly the entire paper but what has impressed me above all else is the fact that the paper depends entirely on observed and observable data.
That is exactly where the scientific emphasis should be.
BRAVO to you, Anthony, and to your veritable army of grant-free volunteers. Together you have garnered data sufficient for many more studies, all of which, it is to be hoped, will be carried out in the true scientific process.
This is truly a job well done!

Ralph

I know you have spent a lot of time on this Anthony, but could you explain more how the max temperatures of poor sites can be considered to be not quite as high as expected. If I have a monitoring station with a ruddy great Trent 900 ( jet engine) pointing at it, I am going to get a higher temperature. So how do such poorly sited stations end up with lower trends?
.

Wellington

Congratulations, Anthony and all.

Congrats Anthony.
Let me recap my long held position on all of this.
The question of bias in the temperature record comes down to three fundament issues.
1. Microsite bias. ( climate near the ground– see geiger to start your education folks)
2. UHI– see Oke to start your education.
3. Bias due to sampling issues. no real canonical text to start with.
1. Microsite bias. By looking at the original field studies on microsite ( performed by Dr. LeRoy’s associate) and by looking at all the studies to date -JohnV, myself, menne, and now Fall et all, we can find no substantial microsite bias that SKEWS the MEAN global temp up or down. This was exactly as some of us expected. Early studies showed the effect, if present at all, was small or within the noise floor. We should also reconize that IF microsite was LARGE we would see discrepencies (large discrepencies) between UHA and say CRU or GISS. That is, the microsite bias, if it existed, would be SMALLER than the differences we see between UHA and CRU or GISS. What about the ROW (rest of the world)? As a pure research project and as a QA exercise I think it makes sense to survey stations around the world. But you cannot expect to find anything different than you found in the US. You can expect to find pretty much the same thing.
2. Mesoscale /UHI. to date the studies done on UHI ( with the exception of Imhoffs recent work) have not taken advantage of up to date Satillite products. A few people are walking down that path; Muller and others I won’t mention. The key datasets here are the ISA data set and the MODIS 500m dataset. Classifying urban and rural is a key uncertainty. However, do NOT expect to find a UHI signal that exceeds .15C.
The small size of the UHI signal must be taken into account in your DOE. if your DOE does not recognize the small effect size, you won’t find the signal. Further, to date all studies have one major failing. They tend to focus on identifying urban by proxies that are not tied to the major causes of UHI. We can look at the causes like so.
1. Disruption of the boundary layer. That is, tall buildings. 3D imagery will be required to classify sites by this.
2. Land use/type AROUND the urban site. Especially water use. Also the building
of dams can transform the weather at Rural sites. That needs to be controlled for.
agri use is also critical
3. Heat capacity changes when rural is transformed to urban.
Those physics are far more important to capture than proxies like population and night lights. In the end, UHA temperatures should lead us to believe that the meso scale bias is small. But, that’s important to quantify.
Bias due to sampling. This is a misunderstood topic. We have no reason to believe that sampling biases the answer. It may however impact our certainty.
The other issue here is the whole historical metadata issue.
In the end, folks will find that the temperature records are sound. Not perfect, sound.
What’s that mean? Well it means that we are coming out of an LIA. It was colder in the past. The world is getting warmer. Our estimate ( say .8c) is pretty darn good considering all the warts in the data and data collection.
The REAL questions are
1. what uncertainty bounds do we put around that number.
2. how MUCH of the .8C is due to changes we have made to the atmosphere?
It has gotten warmer. Some of that is of course natural variability(sun and ocean cycles) . A small part of that may be UHI bias. and some of that, physics tells us, is due to GHGs.
You want a debate IN climate science, that is where the debate is.
If you want to argue that 100% of the .8c is UHI, you’re not in the debate
If you want to argue that it is all the sun, you’re not in the debate
If you want to argue that GHG is ALL of it or NONE of it, you’re not in the debate.
So one way to get the debate you want is to put your numbers down.
1. UHI ( ~.1c)
2. NV ( ~.3c)
3. GHG (.4c)
or any such thing, subject to some constraints.
1. UHI ( ~.8c)
2. NV ( ~.0c)
3. GHG (.0c)
That is not a position that can be defended. So, its not a part of the debate.

James Sexton

Congrats guys! On the road, so I won’t have time to read and digest the paper for a few days. WTG!!!

Snowlover123

I hope that this will be the last time I hear from an advocate “he’s not a climatologist so his opinion is garbage” etc.
I am quite impressed at the authors of this skeptical paper. Not one, but two State Climatologists with PhDs co-authored this paper.
We also have prominent scientists Dr. Souleymane Fall, Robert Pielke Sr. and Dr. John R. Christy, a climate scientist.
And of course we have Anthony Watts!! 🙂

Rob Honeycutt

Yes, congratulations on confirming that all the data sets we’ve all been looking at for so long are not in error. We all appreciate that.
REPLY: Congratulations on the typical non thinking snark response. You obviously didn’t read the paper. – Anthony

Rob Honeycutt

Anthony… I have read the paper and your comments and Dr Pielke’s comments. In their entirety.
REPLY: Really? Must be a snark problem then, because your answer had nothing but that in it. – But it is typical for your track record here. Of course you would have snarked no matter what the paper said. We still don’t know the magnitude of the combined effects, but we’ll have more in the second paper. – Anthony

Rob Honeycutt

I mean, how much more clear can it be?….
“…In the United States, where this study was conducted, the biases in maximum and minimum temperature trends are fortuitously of opposite sign, but about the same magnitude, so they cancel each other and the mean trends are not much different from siting class to siting class.” [emphasis added]
REPLY: Ah you missed a whole bunch, but that’s OK , here ya go, from the Texas State Climatologist:
On the other hand, there are several warning flags raised by this study. First, station siting is indeed important for the maximum and minimum temperature measurements. Second, the adjustments are only partly correcting the temperature record. Third, since the adjustments use data from all surrounding stations, there’s the danger that the mean trends are dominated by data from the poorer stations. (Less than ten percent of the USHCN stations are sited well enough to be considered appropriate for climate trend measurements.) Finally, and perhaps most important, are we really so lucky that the rest of the world would also have its poorly-sited stations have erroneous maximum and minimum temperature trends that just happen to be equal and opposite to each other?
So if you thought that the temperature record in the US was lousy, well for mean temperatures in particular it may not be too bad. (Note: regional conditions may vary.) And if you thought that the adjusted station data had eliminated effects due to poor siting, well for most temperature variables there’s still a ways to go. I’m glad we now have the Climate Reference Network, which should at least guarantee accurate trend measurements going forward.
– Anthony

Rob Honeycutt

Look, Anthony, it’s just as valuable in science to show what doesn’t have an effect as does an effect. In that you’ve done something very valuable. Enjoy it! But I think Pielke’s words are pretty clear here. Station siting quality has no effect on mean trends. Same thing that Muller said. Same thing every other study has said.
Honestly, I’m not trying to be snarky. I congratulate you! I’ve never had my name show up on a scientific paper. Now you have. It’s a great thing. Celebrate it!
REPLY: Ok I’ll give you the benefit of the doubt, thank you, your post appeared to be snark. Bear in mind this is just one analysis, once we drill deeper we’ll know more. One of the big problems witht eh network is that even the best stations are not free from problems, for example the majority of “best sited stations” are at airports, with different equipment. Most of the long term stations with original equipment have been done away with, which is why this project took so long. We wanted to find all of the best stations if possible, there was a plethora of bad ones, dime a dozen. But in reality, no station has gone untouched by change of some sorts. Even the station in Mohonk, NY which is touted as “one of the best” has problems.
Note that Neilsen-Gammon thinks the bad stations may still be swamping the good ones. – Anthony

Rob Honeycutt

But I then need to ask… Do you believe this will, in any way, alter the big picture in climate science related to what is happening with global climate?
REPLY: It may, what we are trying to quantify is how much of the 0.7C to 0.8C trend in the last century is from: natural variation, GHG’s, and other biases (siting, UHI, land use change, equipment change etc.). Once we get closer, we’ll know how much of an impact there is. – Anthony

rpielke

Steven Mosher –
1. Mesoscale and regional land use have a clear significant impact on multi-decadal surface temperature trends. This is much more than the UHI or local effect. For just two examples see our papers
Fall, S., D. Niyogi, A. Gluhovsky, R. A. Pielke Sr., E. Kalnay, and G. Rochon, 2009: Impacts of land use land cover on temperature trends over the continental United States: Assessment using the North American Regional Reanalysis. Int. J. Climatol., DOI: 10.1002/joc.1996.
http://pielkeclimatesci.wordpress.com/files/2009/08/r-329.pdf
Montandon, L.M., S. Fall, R.A. Pielke Sr., and D. Niyogi, 2011: Distribution of landscape types in the Global Historical Climatology Network. Earth Interactions, 15:6, doi: 10.1175/2010EI371
http://pielkeclimatesci.files.wordpress.com/2011/02/r-344.pdf
2. The interpretation of surface temperature trends is made more difficult (i.e. less certain) if there are concurrent trends at the same location in humidity; e.g. see
Davey, C.A., R.A. Pielke Sr., and K.P. Gallo, 2006: Differences between near-surface equivalent temperature and temperature trends for the eastern United States – Equivalent temperature as an alternative measure of heat content. Global and Planetary Change, 54, 19–32.
http://pielkeclimatesci.wordpress.com/files/2009/10/r-268.pdf
Fall, S., N. Diffenbaugh, D. Niyogi, R.A. Pielke Sr., and G. Rochon, 2010: Temperature and equivalent temperature over the United States (1979 – 2005). Int. J. Climatol., DOI: 10.1002/joc.2094.
http://pielkeclimatesci.wordpress.com/files/2010/02/r-346.pdf
3. There is clear divergence in time between the trends at the surface and in the lower troposphere with the warming trend, as diagnosed by the dry bulb temperature, significantly higher at the surface; e.g. see
Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841.
http://pielkeclimatesci.wordpress.com/files/2009/11/r-345.pdf
4. The use of the minimum temperature to assess trends is made more difficult since it is typically a significant function of height above the gound even over a few meters; e.g. see
Steeneveld, G.J., A.A.M. Holtslag, R.T. McNider, and R.A Pielke Sr, 2011: Screen level temperature increase due to higher atmospheric carbon dioxide in calm and windy nights revisited. J. Geophys. Res., 116, D02122, doi:10.1029/2010JD014612.
http://pielkeclimatesci.files.wordpress.com/2011/02/r-342.pdf
These are just four issues, in addition to the siting issues, that raise questions on the “soundness” of the surface temperature data and on the interpretation on the observed trends. That we found systematic biases in both the maximum and minimum temperatures in our new paper alerts us that the absence of a bias in the mean is fortuitous, as this is not a random sampling error.