The first press release announcement thread is getting big and unwieldy, and some commenters can’t finish loading the thread, so I’m providing this one with some updates.
1. Thanks to everyone who has provided widespread review of our draft paper. There have been hundreds of suggestions and corrections, and for that I am very grateful. That’s exactly what we hoped for, and can only make the paper better.
Edits are being made based on many of those suggestions. I’ll post up a revised draft in the next day.
2. Some valid criticisms have been made related to the issue of the TOBS data. This is a preliminary set of data, with corrections added for the “Time of Observation” which can in some cases result in double max-min readings being counted if not corrected for. It makes up a significant portion of adjustments prior to homogenization adjustments as seen below in this older USHCN1 graphic. TOBS is the black dotted line.
TOBS is a controversial adjustment. Proponents of the TOBS adjustment (Created by NCDC director Tom Karl) say that it is a necessary adjustment that fixes a known problem, others suggest that it is an overkill adjustment, that solves small problems but creates an even larger one. For example, from a recent post on Lucia’s by Zeke Hausfather, you can see how much adjustments go into the final product.
The question is: are these valid adjustments? Zeke seems to think so, but others do not. Personally I think TOBS is a sledgehammer used to pound in a tack. This looks like a good time to settle the question once and for all.
Steve McIntyre is working through the TOBS entanglement with the station siting issue, saying “There is a confounding interaction with TOBS that needs to be allowed for…”, which is what Judith Curry might describe as a “wicked problem”. Steve has an older post on it here which can be a primer for learning about it.
The TOBS issue is one that may or may not make a difference in the final outcome of the Watts et al 2012 draft paper and it’s conclusions, but we asked for input, and that was one of the issues that stood out as a valid concern. We have to work through it to find out for sure. Dr. John Christy dealt with TOBS issues in his paper covered on WUWT: Christy on irrigation and regional temperature effects
Irrigation most likely to blame for Central California warming
A two-year study of San Joaquin Valley nights found that summer nighttime low temperatures in six counties of California’s Central Valley climbed about 5.5 degrees Fahrenheit (approximately 3.0 C) between 1910 and 2003. The study’s results will be published in the “Journal of Climate.”
Most interestingly, John Christy tells me that he had quite a time with having to “de-bias” data for his study, requiring looking at original observer reports and hand keying in data.
We have some other ideas. And of course new ideas on the TOBS issue are welcome too.
In other news, Dr. John Christy will be presenting at the Senate EPW hearing tomorrow, for which we hope to provide a live feed. Word is that Dr. Richard Muller will not be presenting.
Again, my thanks to everyone for all the ideas, help, and support!
=============================================================
UPDATE: elevated from a comment I made on the thread – Anthony
Why I don’t think much of TOBS adjustments
Nick Stoke’s explanation follows the official explanation, but from my travels to COOP stations, I met a lot of volunteers who mentioned that with the advent of MMTS, which has a memory, they tended not to worry much about the reading time as being at the station at a specific time every day was often inconvenient.. With the advent of the successor display to the MMTS unit, the LCD display based Nimbus, which has memory for up to 35 days (see spec sheet here http://www.srh.noaa.gov/srh/dad/coop/nimbus-spec.pdf) they stopped worrying about daily readings and simply filled them in at the end of the month by stepping through the display.
From the manual http://www.srh.noaa.gov/srh/dad/coop/nimbusmanual.pdf
Daily maximum and minimum temperatures:
· Memory switch and [Max/Min Recall] button give daily
highs and lows and their times
The Nimbus thermometer remembers the highs and lows for
the last 35 days and also records the times they occurred. This
information is retrieved sequentially day by day. The reading
of the 35 daily max/min values and the times of occurrence (as
opposed to the “global” max/min) are initiated by moving the
[Memory] switch to the left [On].
So, people being people, rather than being tied to the device, they tend to do it at their leisure if given the opportunity. One fellow told me (who had a Winneabago parked in is driveway) when I asked if he traveled much, he said he “travels a lot more now”. He had both the CRS and MMTS/Nimbus in his back yard. He said he traveled more now thanks to the memory on the Nimbus unit. I asked what he did before that, when all he had was the CRS and he said that “I’d get the temperatures out of the newspaper for each day”.
Granted, not all COOP volunteers were like this, and some were pretty tight lipped. Many were dedicated to the job. But human nature being what it is, what would you rather do? Stay at home and wait for temperature readings or take the car/Winnebago and visit the grand-kids? Who needs the MMTS ball and chain now that it has a memory?
I also noticed many observers now with consumer grade weather stations, with indoor readouts. A few of them put the weather station sensors on the CRS or very near it. Why go out in the rain/cold/snow to read the mercury thermometer when the memory of the weather station can do it for you.
My point is that actual times of observation may very well be all over the map. There’s no incentive for the COOP observer to do it at exactly the same time every day when they can just as easily do it however they want. They aren’t paid, and often don’t get any support from the local NWS office for months or years at a time. One woman begged me to talk to the local NWS office to see about getting a new thermometer mount for her max/min thermometer, since it wouldn’t lock into position properly and often would screw up the daily readings when it spun loose and reset the little iron pegs in the capillary tube.
Some local NWS personnel I talked to called the MMTS the “Mickey Mouse Temperature System” obviously a term of derision. Wonder why?
So my point in all this is that NWS/NOAA/NCDC is getting exactly what they paid for. And my view of the network is that it is filled with such randomness.
Nick Stokes and people like him who preach to us from on high, never leaving their government office to actually get out and talk to people doing the measurements, seem to think the algorithms devised and implemented from behind a desk overcome human urges to sleep in, visit the grand-kids, go out to dinner and get the reading later, or take a trip.
Reality is far different. I didn’t record these things on my survey forms when I did many of the surveys in 2007/2008/2009 because I didn’t want to embarrass observers. We already had NOAA going behind me and closing stations that were obscenely sited that appeared on WUWT, and the NCDC had already shut down the MMS database once citing “privacy concerns” which I ripped them a new one on when I pointed out they published pictures of observers at their homes standing in front of their stations, with their names on it. For example: http://www.nws.noaa.gov/om/coop/newsletters/07may-coop.pdf
So I think the USHCN network is a mess, and TOBS adjustments are a big hammer that misses the mark based on human behavior for filling out forms and times they can’t predict. There’s no “enforcer” that will show up from NOAA/NWS if you fudge the form. None of these people at NCDC get out in the field, but prefer to create algorithms from behind the desk. My view is that you can’t model reality if you don’t experience it, and they have no hands on experience nor clue in my view.
More to come…
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
” There is no evidence in Watts et al. that the good stations are adjusted to the bad ones”
There is no evidence that there was intent on the part of NOAA to adjust good stations to agree with bad ones, but the methods they chose had that effect. I would hope this is something they would want to examine and understand.
Has a table been made available with the drafts with a list of 1+2 stations so Joe Blow can download the raw time series for each station?
Christopher Dollis: “If that’s all it was — that a given station might be half a day off — then no one would care.”
That one’s on me. I didn’t mention in that post that it was is in respect to aligning times between multiples stations. For a single site the notion would be meaningless, of course.
“But it isn’t just that. It’s that day-in, day-out, the time the daily minimum/maximum-recording thermometers are reset can bias the results.”
Sure, iff the temporal variance is enough to cause problems. But there are two time tested solutions for these problems. One does not alter the data recorded, nor the trend present in the data at all: Error bars. Completely safe and cheap to model. But terrible for the Chartporn Powerpoint of Doom: “On the side of the Titanic, that big freakin’ ship right there, there is a porthole that will cause a catastrophe. Which one? Can’t tell exactly, but there’s a lot of those tiny little buggers bolted right up. Smug bastards.”
The other will, like any adjustment to the data, bias the trend. Note: The data itself does not bias the trend, it *is* the data and we have absolutely no other knowledge. It’s a simple one-line in any statistical package and it’s called a moving average. If we’re concerned about yesterday in today and a part of today into tomorrow? 2 item moving average. Well known, needs no defense in general, alters the trend just as will including unicorns farts in the daily temp for stations in Wichita.
This isn’t pointed at you, mind. But if anyone wants to justify why we need unicorns farts in cornfields to homogenize the cold prairies up to the steam pipes under NYC then they need to first justify why completely harmless and common methods used even by the likes of Mann, Briffa and other notables (And unnotables, if you wish to eyeball the mere Weathermen running around here.) are wholly unsatisfactory corruptions of the empirically measured data.
And no, just no. A childhood allergy to error bars isn’t an excuse. Not even if you’re a Climate Scientist. Not even if you have a Nobel Prize. Not even if you have a Doctor’s note.
Without such justifications as to why every statisticians has gotten wrong for a century then it’s not data, not a theory, not science, but a product. But then so are used cars.
Christoph Dollis says:
August 1, 2012 at 9:42 am
Anthony makes a good point about how, particularly in light of newer thermometers that need to be read less often, human nature causes people to have fudged the forms instead of paying attention to strict timing, but that’s a separate issue.
================================
“Fudging”
Way back in the day when I was the opening person for the college radio station, one of my jobs was to go outside and get the weather data. (if my memory serves me correctly, it may have been a Stevenson screen). And since I really didn’t care how accurate the information was on many very,very cold days, I can tell you that there was much fudging.
I find this discussion about TOB and other data adjustments utterly confounding. There are something like a dozen peer reviewed papers on TOB adjustments alone – you can find a bunch of them here:
http://agwobserver.wordpress.com/2012/08/01/papers-on-time-of-observation-bias/
It seems to me that if commenters on this site really wanted to understand data adjustments made for TOB, they would start by looking at the actual scientific literature on it, and actually try to understand how and why the adjustments are made.
Well, Anthony, it was a late for ya last night. But I have an idea. Your comment concerning the human factor and how folks actually do the readings could turn out to be another mission. Create a post specifically for folks who are now doing or have in the past been observers. Kind of a online survey. Have pertinent questions along with the freedom to comment. Do a press release calling out to all to come and post on how they did their readings.(Facebook is another good avenue) It could be a very worthwhile endeavor. Just a suggestion. I really think we’d all be very surprised at the results. People are people, not robots. I know if I knew I could read an MMTS just once in awhile because of its memory capacity, I would. You’d be getting the temps you need, and it wouldn’t be a burden on me in the midst of a sometimes chaotic life.
Anthony, to the extent the US instrument siting problem is global, then there should be a growing divergence between satellite measured global temperatures, global surface temperatures, and global land temperatures (for example in GISS). I cannot paste in the chart here, but comparing UAH to HadCrut to GISS land only makes the case very nicely from 1980 (assuming MMTS started in the mid 1980’s). Did not run the exact statistics yet, but from 1995 to 2005 the divergence between UAH and GISS land is on the order of 0.3C, and on the order of 0.15C to HadCrut. Basically supports your conclusions about compromised data incorrectly homogenized in the wrong direction.
Brian H says:
August 1, 2012 at 9:44 am
“Places with variable weather can throw min/max thermometer assumptions out the window. If a cold day is followed by an overnight (say, 2 a.m.) warm front moving through, the MIN will still show the cold day’s measurement, even though it might be much warmer by the following sunrise. IMO only continuous plots, with frequent data point recording, can get around this. And then the whole “MIN/MAX issue is almost moot, because now you have real integrated temperature plots and actual averages, not stupid medians, are available.”
Brian H. – I’m with you. I’ve thought about this TOBS issue, and my impression is that one can’t really know very much about a continuous function (ambient temperature at a point in space versus time) given two values measured within a 24 hour window at unknown times (i.e. we don’t know exactly when the max and mix temperatures occurred). Why not simply plot the max and min temperature series as two separate discrete functions (no TOBS needed) and estimate the trends for each. I’m sure someone has done this.
Also, if one is considering the modern era of say 1960 to the present, we should have plenty of hourly data with which one can compare with nearby climate monitoring stations, again allowing the TOBS adjustment (if any) to be more precisely determined for the climate min/max readings. Maybe someone has already done this as well (and I confess I haven’t read all of the TOBs papers save for ones by Karl et al.).
J. Philip Peterson says:
August 1, 2012 at 9:32 am
beng says:
August 1, 2012
“If the station is otherwise consistent/unchanging, being in a frost hollow has no effect on the trend.””I agree and if the station is atop a 6288 ft mountain it has no effect on the trend:
http://weather-warehouse.com/WeatherHistory/PastWeatherData_MtWashington_MountWashington_NH_August.html
___________________________________________________________________
This is definately a rural site, unless someone has built a restaurant up there!
Just for amusement I calculated the ten year average, 1948 to 1957, and compared it with the ten year average for the most recent 10 years. The older mean is 47.1C and the newer 48.86C.
The trend is +0.27C per decade.
My God , they did build a restaurant up there!http://www.mountwashington.org/about/visitor/summer_visits/expect.php
Entropic man says:
August 1, 2012 at 10:54 am
J. Philip Peterson says:
August 1, 2012 at 9:32 am
beng says:
August 1, 2012
“If the station is otherwise consistent/unchanging, being in a frost hollow has no effect on the trend.””I agree and if the station is atop a 6288 ft mountain it has no effect on the trend:
http://weather-warehouse.com/WeatherHistory/PastWeatherData_MtWashington_MountWashington_NH_August.html
___________________________________________________________________
This is definately a rural site, unless someone has built a restaurant up there!
Just for amusement I calculated the ten year average, 1948 to 1957, and compared it with the ten year average for the most recent 10 years. The older mean is 47.1C and the newer 48.86C.
The trend is +0.27C per decade.
____________
Which month did you calculate for? I made several graphs in excel for ‘Mean Temperature’ for the months of Jan., April, June and Oct. and only April showed an increase from 1948 to 2012 of approx. 3 degrees F max. The other 3 months were even or even trended down.
Entropic man says:
August 1, 2012 at 10:54 am
“This is definately a rural site, unless someone has built a restaurant up there!”
Actually…there is a cog railway to the top, an auto road to the top, and a visitor’s center at the top, complete with gift shop. 🙂 Definitely worth a visit if you’re visiting New Hampshire (except in the winter, of course). Bring your jacket…
A critique of the article from Skeptical Science:
http://www.skepticalscience.com/watts_new_paper_critique.html
This seems to imply a midnight effective TOBS unless the recorder goes to the trouble to convert it to a different effective TOBS.
Midnight will tend to double count cold nights, and therefore be similar (but not identical) to 7AM.
There’s a good comment at CA w/links to PielkeSr studies on the TOBS. As you would expect, the TOBS adjustments made by NCDC don’t make alot of sense…
http://climateaudit.org/2007/02/16/adjusting-ushcn-history/#comment-79771
Anonymous Coward: “I find this discussion about TOB and other data adjustments utterly confounding.”
What’s confounding is that you didn’t bother to skim the abstracts of the papers at your link. A quick run through of the worst offenders:
Vincent (2009): “Not all days are affected by this change in observing time, and the annual percentage of affected days ranges from 15% for locations in the west to 38% for locations in the east.”
Playing with the reset time does not cure epistemic ignorance of when then highs and lows occur, or solve the problem that they occur at difference times on different days. Makes the same error of state that the midpoint of a range is a ‘mean’ temperature for a day. This is wholly illiterate with respect to basic mathematics.
Janis (2012): ” Surprisingly, non-calendar-day observations are similar to calendar-day observations on a majority of days. When differences do occur, however, they can be large and of either sign.”
Time of Tmax and time of Tmin vary, but are unknown. We already know that, but we cannot conjure up a stopwatch that does not exist. Not a problem of data collection but PEBKAC. Trying to ‘move’ temperatures out of a 24 hour window into some other time frame in absence of knowledge.
DeGaetano & Knapp (1993) : “Simulations using hourly temperature data indicate that the period required to reach a given GDD threshold value during a growing season often varies by 2 weeks or more solely because of observation time differences. Previous work on methods to adjust such biases has concentrated on seasonal totals and long-term averages. ”
Past work is based on the long term average of the midpoint of a range. Invalid for the purpose D&K are after, good enough. But the GDD is based on the ‘mean’ temperature of the day as purported to be the midpoint of the range. Again, mathematical illiteracy.
Karl et al (1986) : ” Using seven years of hourly data the standard errors of estimate using the model were only moderately higher than the standard errors of estimate of the true time of observation bias.”
Modeled adjustment is, if the paper is read, outside the confidence interval for estimating the TOB on the basis of hourly observations. Same issues of mathematical illiteracy as before. The paper mentions that issues of skew were found in two mentioned months, but no analysis is undertaken with respect to skew or any arbitrary bias introduced from a model out of statistical bound of an estimate of a midpoint of a range. Useless.
Byrd (1985): “The modified method involves adjusting data to a “true” mean obtained by averaging all hourly temperature values for the 24-hour period ending at midnight, rather than adjusting to the midnight standard observational mean obtained by averaging the maximum and minimum values over the same period. The adjustments are applied to mean temperatures from stations with different observation times in the region around Oneonta, resulting in spatial analysis fields which are believed to be more representative than those using the published data.”
Attempts to apply an *actual* mean — for once, thankfully — to the midpoint of the Tmin/Tmax. Mathematical illiteracy. Didn’t bother to read this one for sd, or skew issues.
Blackburn (1983): ” A scheme for adjusting these reports to eliminate the biases and make them conform to the midnight-to-midnight reports of first-order weather stations is described.”
Same mathematical illiteracy as previous. Bonus points for homogenizing weather. GIGO.
Schall & Dale (1977): ““Historical changes in time of once daily maximum and minimum temperature observations at cooperative climatological stations from 1905 to 1975 have introduced a systematic bias in mean temperatures. Unless corrected, this bias may be interpreted incorrectly as climatic “cooling” and may also affect the assessment of agricultural production potential and fossil fuel needs.”
Funny that the next ice age was the big thing back then. Once again, the midpoint of a range is not a mean temperature for any 24 hour period. Mathematical illiteracy.
Baker et al (1975): “Comparisons of the annual and monthly mean temperatures showed deviations can be of such magnitude as to discourage comparison of station temperatures and temperature-derived quantities such as HDD and GDD unless observation times are the same or corrections are applied”
Baker here properly distinguishes between a true ‘mean’ and ‘Tmean’. Kudos to baker. As noted here he concludes the homogenizing station data is a farce unless you fudge. Too bad Baker, “weather is not climate” and homogenizing is nonsense. Though, to be fair, they were still stocking up on coal for the coming ice age in 1975.
All save one of those not mentioned, that had abstracts, were about detecting TOB via various means. Which is fine for what it’s worth. But let’s reiterate Baker (1975) once more: “These data were used to calculate 1) a true daily mean, 2) a mean of the maximum and minimum between successive midnights as observed at first order stations, and 3) a mean of the maximum and minimum observed at all other hours of the day to simulate cooperative station means.”
None of these things is like the others. And the uninformed yahoo’s here knew more about the contents of your link dump then you yourself did. Good job on your efforts.
Nope. And I never indicated nothing or the sort. Stop putting words in my mouth I did not say.
What I did say was the links collected appear to include all the data- both temp and station info, along with the Leroy(2010) siting standards, so you or anyone else could do the same thing Anthony has done …..go thru the temp and station data, apply the Leroy(2010) standards yourself, and generate the data the Watts report did.
I included a link to the USHCN metadata files and a link to Anthony’s Surface Stations info as well – both which give a reviewer data on the station history and siting data.
The graph of NOAA adjustments above and at http://wattsupwiththat.files.wordpress.com/2012/04/ushcn-adjustments.jpg is labeled degrees Fahrenheit, but then the footnotes refer to degrees Celsius. Use with caution!
This is a good place to go to get comma delimited files for the USHCN network. Has raw, TOBS, and full adjust files. You can also generate graphs as well.
http://cdiac.ornl.gov/epubs/ndp/ushcn/ushcn_map_interface.html
This would seem to be true regarding that single station … as with UHI effect, if the conditions remain the same the station trend should be unaffected. But when it comes to the larger record, a station that consistently reads low will, in my understanding, clearly affect the larger record.
As far as I know we compare temp data to generate trends – we do not compare trend data itself. Add in a low reporting station and your larger scale trend data is now changed.
Thanks for all the TOBS info everyone.
My next sleepless night will be dedicated to its contemplation, and hopefully a better understanding of the apparent issues.
It is not like global warming is gonna jump-up of the sudden and create catastrophe, so the time-sink of including the TOBS seems a reasonable course of inquiry.
If it keeps the CAGW theory alive.
A lengthy display of, to me, largely gibberish – intended to refute the Watts paper through obfuscation.
While completely ignoring and failing to address it seems the whole point of the Watts paper – to apply the new WMO endorsed Leroy(2010) siting standards and see what effect it has.
Which ironically the posters in the comments acknowledge is a valuable contribution.
Hu, or this one:
http://www.ncdc.noaa.gov/img/climate/research/ushcn/ts.ushcn_anom25_diffs_urb-raw_pg.gif
Maybe it was wrong in areas, but it wasn’t “obfuscation” — its positions were clearly stated.
wsbriggs says: August 1, 2012 at 6:48 am
“I have an issue with the idea that we will record the min/max within a single 24 hour period every day, and then complain and insist that if the next day’s max occurs within one second after the end of the previous 24 hour period, that it is invalid.”
Who is saying that it is invalid? It’s a measure. The problem is that the result depends on the time of day when you took those readings. It’s changing that time for a station that creates the need for a TOBS adjustment. Otherwise there is a spurious step change.