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…
Given my limited knowledge on TOBS .. it would seem to me that the ajustment would be highly station dependent, and thus, no blanket adjustment could be credibly done.
Where I live, it would seem missing the “low” would be more likely than missing the “high”. Things warm up, max around 3 pm, but cool off very slowly. So a temp reading of 4 pm would not be much different, if at all. In contrast, the min, happens just before sunrise, and warms up rapidly. Taking the min an hour late would result in a false “warm” reading.
Further, Fronts happen. Sometimes the Max is at Midnight, and the Min is at 5 pm.
Since I notice that all TOBS adjustments seem to increase the warming trend, it seem pretty obvious to me that this whole adjustment has an “end” as its goal .. ie., to create a greater warming trend that exists.
I suppose with something as big as the climate sea there are bound to be a number of red herrings but really. The effect that Anthony has shown is not altered by TOB’s , by error bars, by new and improved snazzy mathematics. It simply shows how the different classifications of reporting stations have differing rates of temperature increase. He shows that this is an artifact of the methodology used by NOAA. This is important because a lot of research has been done on finding out why the NOAA data shows what it does and the data is wrong which means the research was often looking in the wrong place for the wrong answers. Much wasted time and effort.
By all means let’s look at the other niggles just so we can be certain they don’t, collectively, compensate for the error found by Watts et al. and thus make NOAA correct once more. Now that really would be a 5 sigma result worth considering. Ah, CO2 you amazing little molecule is there nothing you can’t do? /sarc
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. When you sample, you sample. Yes, the max for the previous 24 hour period was one second prior, but we are asking for the max temp within a 24 hour period. They fall where they fall. Humans would experience the 24 hour period exactly as the min/max thermometer does. It got cooler after X AM/PM. Arguing that the max was double counted seems to be arguing that we really don’t want to know the 24 hour min/max. This doesn’t change with continuous sampling – the max was still 1 sample after the 24 hour reset.
To exaggerate, during a 24 hour period, a micro downburst occurs in the vicinity of the instrument chilling it substantially below the temperature before and after the event. The thermometer records the min temp faithfully. Should we nuke the temp? A human standing there would have felt it. NOTE: this is NOT the same as a jet exhaust, it is a meteorological event.
A. Scott: Seems everything is there to reproduce the work for the people who question the results. I did it on my own
You were able to recreate the list of USHCN station ids and their associated Leroy 2010 classification? Well done! Perhaps you can sure the list with the slow half of the class.
On the first large industrial experiment I organised, I strolled into the control room at 12:15 and looked at the record sheet: the results for 13:00 had already been written in. Such is mankind.
The existence of a TOB has been known since 1848! Also look at the link in the comment this jumps to, it has a substantial list of papers on this bias, with the earliest one being 1890!
http://variable-variability.blogspot.com/2012/07/blog-review-of-watts-et-al-2012.html?showComment=1343822752641#c3498478472825631256
I know a rural station, not in the US, notorious for underreading because it is in a frost hollow. Winter Tmin values are consistently lower than others in the region, giving distorted winter daily temperatures and the lowest annual average temperature for 200 miles.
On the basis of an estimated error of about -2C relative to its neigbours it would be classified Class 3, but otherwise meets most of the requirements of Class 1. Reading through the class descriptions, they all discuss warming effects such as parking lots or air conditioners, but even shading is barely mentioned. I site such as this is not catered for at all.
Is it me, or are both the USHCN and surfacestation.org exposing themselves to sampling bias assuming in their classification that all low class stations overread? The TOBS, MMTS and SHAP corrections all assume that the temperatures need to be adjusted upwards, which would make the error in this station even worse!
In a 20 minute sample search of USHCN and surfacestations.org I found a number of stations classified as low quality due to overreading, but nothing to match the station described above.
Anthony
I remember seeing a graph a couple of years ago showing the number of reporting stations vs the temperature trend. It indicated a significant drop in reporting stations (most of them rural if I remember correctly) around 1990 after the collapse of the USSR, and a corresponding (though possibly not correlated with) increase in the temperature values. I realize that most of the decrease in station count was not in the US, but did your team consider the impact of fewer rural stations in your paper? A quick scan did not indicate that this change was mentioned in your article. Since you show that the rural temperature increase has been much less than the other areas and the “adjusted” final tempearture trends, I have two questions:
1) Is the impact of the reduction in rural stations in the US statistically significant?
2) If the rural trend is so much less than the trend from the other stations, why is the UHI adjustment only 0.05C? Seems like it should be on the order of .5C or more.
Bill
I challenge those who have been able to download the Raw and Adjusted USHCN V2 data, to publish the (annual or monthly) numbers.
Steven Goodard has here.
http://stevengoddard.wordpress.com/2012/07/16/how-ushcn-hides-the-decline-in-us-temperatures/
So that results then in total Adjustments of 0.84C to the trend in USHCN V2.
– TOBs only increases the trend by +0.399C (from 1934, funny how that year has the biggest change); but,
– Other adjustments are +0.500C.
I’ve pinned all the data to 2011 so that we can actually see the total change (while others have produced charts that obscure the changes by using a baseline averaged in the middle).
Total Adjustments first.
http://s15.postimage.org/wzzrg9k0b/Total_Adjust_USHCNV2.png
Raw, TOBs and Final annual numbers next.
http://s16.postimage.org/ux7avs6qt/USHCNV2_Raw_Final.png
Now perhaps Steven’s numbers are off some. I used the most recent Final numbers from the NOAA to do the charts and they were slightly different.
But all those who have the Raw, and Final data should make the data available so that we can see just how much these adjustments add to the trend.
Sorry TOBs adjustment above should say +0.339C (not 0.399C).
Yeah, I ran into one of those consumer weather station in the CRS types in the Dakotas, at a sugar beet processing plant. Temps were taken by the guards at the guard station. One told me the issued thermometer developed a bubble, and they asked NWS for a new one, but it wasn’t forthcoming, so they just went out and bought their own. Tho, coincidentally, I’m sure, this happened in a Dakota’s February.
Wireless, of course, and the guard station itself was indoor/heated.
TOBS is i have been reading not the time of observation but the 24 hour period in which the Tmax and Tmin occurs and every 24 hour period has a Tmax and Tmin so the data can be adjusted to refer to the same 24 hour period without I think introducing a trend in the data.
Seems to me TOBS is complicated. A tropical or lower-latitude site would have less bias w/the same observation-time changes as a more poleward site affected by fronts because low-latitudes would have more consistent min/max time-occurrences compared to front-affected sites. How does one quantify those different situations? One would have to spot each & every occurrence of double-reporting for each site to get it right. Estimating algorithms would be prone to the usual inadequacies, tinkering and abuse.
Yeah, I’ve briefly looked at the methods used for TOBS, and that’s why I make the remark about their efficacy.
****
Entropic man says:
August 1, 2012 at 7:20 am
I know a rural station, not in the US, notorious for underreading because it is in a frost hollow. Winter Tmin values are consistently lower than others in the region, giving distorted winter daily temperatures and the lowest annual average temperature for 200 miles.
****
If the station is otherwise consistent/unchanging, being in a frost hollow has no effect on the trend.
There’s always going to be some measurement uncertainty. It’s just a fact of life in science. Quantifying it is part of science.
donald penman: “TOBS is i have been reading not the time of observation but the 24 hour period in which the Tmax and Tmin occurs and every 24 hour period has a Tmax and Tmin so the data can be adjusted to refer to the same 24 hour period without I think introducing a trend in the data.”
Yes, that is one of the ham-fisted notions for it. But the notion for a trend is what now for climate? Last I remember was 13 or 17 years. But let’s say 13 years and that we’re dickering over a temporal jitter of +/- 12 hours with respect to solar noon. That’s a +/- 12 hours jitter over 133,880 hours covering 4,745 samples. Not counting leap years because I’m lazy.
If that’s enough to scrobble up your trend? Buddy, Jeane Dixon and Uri Geller don’t need that of much handicap to make predictions.
Bill Illis says:
August 1, 2021, 7.36am
“(from 1934, funny how that year has the biggest change)(while others have produced charts that obscure the changes by using a baseline averaged in the middle).”
You see a lot of that from both extremes in the climate change war. I have seen cherrypicked data used to support arguments for extreme warming , and for none. My favourite is the people who tell me there’s been no global warming for 15 years, starting from just before the exceptional El Nino year of 1998/sarc.
http://www.drroyspencer.com/wp-content/uploads/UAH_LT_current.gif
beng says:
August 1, 2012 at 8:13 am
“If the station is otherwise consistent/unchanging, being in a frost hollow has no effect on the trend.”
Fair enough, though it does make that region, with only two dozen stations, appear cooler than it is.
My main concern is that the apparant lack of frost hollow stations recognised in USHCN or surfacestations.org is distorting both datasets.
Martin Lack says:
Also, if global warming stopped in 1998, perhaps you can also explain to me why May 2012 in the USA was… “the 327th consecutive month in which the temperature of the entire globe exceeded the 20th-century average, the odds of which occurring by simple chance were 3.7 x 10-99, a number considerably larger than the number of stars in the universe.” — Bill McKibbin (Rolling Stone magazine)
May 2012 was warm relative to the 20th century average because the earth is warm relative to the 20th century average. “Warm” is not the same as “warming”. If the temperature of the earth stays the same as it is today for the next 100 years (i.e. warming stops) the temperatures recorded in 2112 will still be warm relative to the 20th century average. The odds presented by Bill McKibbin are wrong, and the conclusion that he draws from them is a non-sequitur which would not be correct even if the odds he presented were right.
Bill McKibbin is an idiot, and one should look to Rolling Stone for commentary on drugs and music, not science and math.
beng says:
August 1, 2012 at 8:13 am
“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
If that’s all it was — that a given station might be half a day off — then no one would care. 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.
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.
What I want to know is why TOBS adjustments always go up. TOBS should balance itself out. If you can go one way with the bias, you can go the other way with the bias. And over a large sample size, the stochastic effects will just nullify. But you never see a downward adjustment.
It seems completely arbitrary. Where is the empirical, experimental evidence?
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.
On NPR……
Global Warming Debate Heats Up, Again
Of course, when a team member defects, his/her ex-teammates shoot back quickly. A day after Muller’s op-ed piece, Anthony Watts from the privately-owned IntelliWeather, posted a piece in his blog Watts Up With That, where he claims that the data of U.S. temperature trends shows a spurious doubling due to station measurement issues.
http://www.npr.org/blogs/13.7/2012/08/01/157659554/global-warming-debate-heats-up-again