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!
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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…
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Johanna, Steve McIntyre said that temperature records generally are a time sink, and that basically he accepts the official records, if not in fact then as a reasonable basis to start working from. .
Well done. I’m happy to see this study being discussed in the mainstream media. Doing great science is one thing. Getting the press to cover it is another. Well done.
No, Steve Huntwork 5:46pm is *NOT* right on the money. Anyone that correctly understands TOB does not claim that the actual recorded temperatures are in error. Changing the time that the max and min thermometers are read will cause a change in the resulting computed monthly mean values vs. what they would be if the time had not changed. This will show up as a step change in the temperature time series at the point where the time of observation is changed, and if you add a step change to a time series, you change the trend. If the step change is artificial – e.g. because the methodology changed and not because the climate changed, then you just artificially biased the trend. The question is not whether TOB needs to be adjusted for, it is by how much.
Christoph Dollis says:
July 31, 2012 at 9:13 pm
“…the average amplitude of a Sine wave is always 0.”
Only if it is not clamped.☺
What doesn’t make any sense is that the UNHCN TOBS adjustments since 1970 have ALWAYS increase the warming trend.
MUST be just coincidence , I guess.
Eric Barnes says:
July 31, 2012 at 7:18 pm
Reading the Karl TOBS paper here
ftp://ftp.ncdc.noaa.gov/pub/data/ushcn/v2/monthly/karl-etal1986.pdf
———————————————
I haven’t found a reference for the data in his table 1 (Percent of am, pm and md cooperative weather stations in the US). That data is essential for the amout of correction and in the paragraph referring to table 1, there is only a reference to a “personal communication” with Shoun in 1985.
And is TOBS applied as well outside the US and on what data base ?
Christoph Dollis says:
July 31, 2012 at 8:38 pm
No worries, Anthony.
Great work, on balance. I’ve critiqued you today for rushing to press so it may not seem like it, but your site is and has been for years one of my favourites and I greatly appreciate your work. I think it’s valuable not just to science, but to humanity … considering the terrible ramifications of bad environmental and economic policy.
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A little off topic, but I think this wasn’t so much a rush to press as a use of a new medium. I’ll liken it to the time when religious and legal papers were all written in Latin. The people didn’t know latin so they didn’t really know what the clergy and the lawyers were talking about. (WARNING! I’m about to twist a figure of speech to the breaking point.) This paper hasn’t yet passed through the Latin process of peer-review but it (a draft ot it) was put out there in English for the people to read and try to understand and critique even though much of it is still Greek to us. (Whew!) “People-Review” before “Peer-Review” is a good idea.
Someone once told me, “It’s what you learn after you think you know it all that matters.” I don’t know if they were quoting someone else or not, but maybe it’s time the peer-review process learn something that matters.
I am still not ‘getting’ how TOB affects more than the day of adjustment.There is a recorded min and max and if it starts high and goes low or the other way or starts in the middle after one day of shift will be balanced again.
JR : July 31, 2012 at 9:25 pm
said:…. ” Changing the time that the max and min thermometers are read will cause a change in the resulting computed monthly mean values vs. what they would be if the time had not changed. This will show up as a step change in the temperature ….”
OK, granted.
But then, how many times have they changed the TOBS? How many steps are we talking about?
… and is it always in a direction which adds an error, and so needs to be adjusted down?
Two separate issues here. To be sure, a lot of people here don’t yet understand TOB (and it’s a new concept for me also). However, recorded temperatures may still be in error due to poor site design and maintenance (you didn’t dispute that; just throwing it out there, since that’s a major part of Watts’ paper).
Not calculating the TOBs, which Anthony feels are minor anyway, isn’t my major concern. My major concern is more interpersonal: that McIntyre felt a bit rushed and not yet comfortable with having his name on the paper. I feel (and I think it’s little in doubt) that it would have been better to give Steve a bit more time. Anyway, water under the bridge and all that.
The discussion has started and it’s an important discussion. I believe Anthony has definitely identified differences in the rate of temperature increases in various stations depending on their Leroy 2010 classification, and also shown that airports are nearly wholly unreliable for fine climatic measurements. Worse, the data homogenization-adjustments use the worst sites as a starting point rather than the best sites, revealing a bias toward warming on the part of most climate scientists.
“People-Review” before “Peer-Review” is a good idea.
I should add that I left out “Press-Review”n purpose.
Changing the measuring time could add a mean error up or down. On balance, it may be very minor as Anthony feels. However, to be thorough and as certain as possible, it’s right to address it as Steve is doing.
dalyplanet says:
July 31, 2012 at 9:46 pm
I am still not ‘getting’ how TOB affects more than the day of adjustment
—————————————–
If you are reading data around minimum temperature time of a day and then reset, the next measured temperature will be the same minimum again and may remain the minimum for the next day as well if it doesn’t get colder. You then have a 2 day minimum value measured on one day for both days and that is a cold bias. The other way round if you read around the maximum time.
JR says:
Changing the time that the max and min thermometers are read will cause a change in the resulting computed monthly mean values vs. what they would be if the time had not changed. This will show up as a step change in the temperature time series at the point where the time of observation is changed, and if you add a step change to a time series, you change the trend. If the step change is artificial – e.g. be…. The question is not whether TOB needs to be adjusted for, it is by how much.
JR, I think your notion of an artificial step change my be the key issue. However a one day mistake should not impact the annual average so any such adjustment seems totally unnecessary… unless you are concerned about how any step changes affect the homogenization process. Often their algorithm interprets a step change as the point where adjustments needs to me made.
By the way, I think it’s possible TOB adjustments will be significant in and of themselves. However, I have no reason to think they’ll trend any differently for airports vs. non-airports, rural vs. suburban vs. urban, Class 1 sites vs. Class 4, etc.
I’m curious, though, now that Steve McIntyre is looking into it. Might as well see what he comes up with.
” Steve Huntwork says: July 31, 2012 at 5:46 pm
“TOBS has always been a dating issue and never a temperature offset.”
Steve, you frequently refer to your experience at stations taking hourly readings. That’s not what TOBS is mainly about. It’s dealing with the history of stations that used min-max thermometers, which were reset once a day, and which recorded mechanically the min and max between the resets.
The intention is to represent the day’s temperature as the mean of the min and max for that day. Not ideal, but it’s the record that we have, and OK if it is consistent.
But suppose that the reset is at 5pm. Then when a cool day follows a warm one, it can happen that the highest temp over the 24hr period was at 5.01pm on that previous warm day. So in effect, the warm day is counted twice. If a warm day follows a cool, however, it is very unlikely that 5.01 pm will be the coldest point of the warmday cycle. So warm days are double counted, cold not. That’s a warm bias. Morning readings have a similar cool bias.
As long as it is consistent, that doesn’t matter much. The problem comes when you shift from evening reading to morning. Then there is a corresponding cool bias, and the change gives a cooling step.
Now the NWS relied a lot on COOP volunteers. It asked them to reset in the evening, but read rain gauges in the morning. They tended to shift after a while to reading both in the morning. That’s a cooling trend.
There’s no supposition here. The reset times are recorded. There is a lot of information on the diurnal cycle, and day-to-day variation. There’s a clear need to adjust when reset times changed, and the numbers are there to do it.
davidmhoffer says: July 31, 2012 at 8:08 pm
“While I understand the TOBS issue, what I don’t understand us why TOBS must be applied to this particular analysis.”
As McSteve says, it’s an important confounding effect. The reason is that TOBS applies where a change was made, and this occurrence is very likely to be related to CRN status. And it is a big effect.
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
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…
There’s lots of stations and TOBs should be randomly spread across the board – you’d think. So can’t see how accounting for it will make a whole lot of difference to the main conclusion.
JR @ur momisugly 9:25: ” Changing the time that the max and min thermometers are read will cause a change in the resulting computed monthly mean values vs. what they would be if the time had not changed. ”
Angels dancing on the head of a pin. The midpoint of two extremums of a range is not the same as the average of 24 individual samples over some given time or even just 2 samples spaced 12 hours apart. Such a midpoint is neither a mean, median, nor mode; and it makes not a lick of difference if you call it ‘Tmean’, ‘Tgreen’, or ‘greenT’. It does not and cannot represent any notion of area under a curve.
The entire fret about TOBS is simply a canard based on a mathemagical sophistry. Every Tmin/Tmax pair represents the extremums over, notionally, the prior 24 hours. The only manner in which this can be effected by time of observation is if the *specific time* at which a Tmin event and a Tmax event occur is not fixed day to day. But that only states that what we are doing *is not taking an samples at specific time intervals.* But we already knew that, didn’t we?
Changing the TOB for a given site can only reduce or increase the interval over which we collect extremums *one time* per change. That is, it can only produce a single spurious outlier. If you have enough such outliers then it is certain that your dataset is garbage for that site and no amount of massaging will repair it. But if a single spurious outlier is enough to destroy your trend over 365 24 hour sampling periods?
Then you were trying to speak more accurately then your instrumentation allows. Nothing but GIGO.
Thanks for that great explanation, Nick — it’s the best I’ve seen so far. From what you say it’s a bigger effect than I thought, too.
Now that I understand it better, I don’t agree — not at all:
Now I will say there’s no reason to assume the effect is more or less at the various types and classifications of sites. So maybe it’ll all average out. However, it appears to be a significant introduced bias and should be accounted for if the data is available to do so.
Why not remove unnecessary doubts and avenues for attack?
At the end of the day, what I take away from this is that so many data quality issues surround just the last century or so of data that trust necessarily becomes a matter of faith.
While fascinated by this discussion, I spent some quality time this evening perusing the papers here: http://www.clim-past.net/8/issue4.html
The abstract, discussion and conclusions sections of which will really broaden your perspective as you further ponder when we live, the half-precession old Holocene, the efficacy of TOB, station siting etc.
Do the same for http://www.deas.harvard.edu/climate/seminars/pdfs/Tzedakis_etal_2012.pdf and see what sense you make out of all this.
Makes for an interesting evening, just sayin.
Anthony struck a nerve with media matters,
http://mediamatters.org/research/2012/07/31/conservatives-still-trying-to-dispute-global-te/189034
REPLY: Yeah they’ve pretty well flipped out. Can’t have any questions you know.
And what a bunch of hypocrites, they quote everyone else, including 3rd person disturbed Bunny Boi who they outed:
…but they don’t dare link to the Watts et al paper for anyone to read for themselves. -Anthony
As someone in here pointed out a long time ago…
If you find an added historical uncertainty to the parameter you are measuring, rather than “adjust the historical data”, should you not simply widen the error bars?
Can I please reiterate that Watts et al is not proposing a Grand Unifying Theory of Climate, or even of climate measurement. It is clearing some of the underbrush so that we can move forward. People who complain that it doesn’t address their particular concern are missing the point.
At a minimum, this thread tells us that TOB is a highly contested area. Blaming Watts et al for not resolving it to everyone’s satisfaction is like complaining that antibiotics do not cure the common cold.