tag:blogger.com,1999:blog-9093436161326155359.post2670003678041017825..comments2024-03-07T06:13:15.953+00:00Comments on Variable Variability: Blog review of the Watts et al. (2012) manuscript on surface temperature trendsVictor Venemahttp://www.blogger.com/profile/02842816166712285801noreply@blogger.comBlogger123125tag:blogger.com,1999:blog-9093436161326155359.post-88649950280799533732012-08-05T14:18:59.533+01:002012-08-05T14:18:59.533+01:00Not making any TOB corrections is like an epidemio...Not making any TOB corrections is like an epidemiological study on the relationship between diet and cancer, which would not correct for smoking or age. Just like we know that smokers typically have a poorer diet and it is thus easy to get spurious correlations, we have reasons to expect that the TOB correction correlates with station quality. For example, the voluntary stations tend to be rural, the professional ones (staffed around the clock without TOB problem) tend to be in cities.<br /><br />Even if by coincidence it will turn out that the TOB corrections not to create any problem, you cannot call something a scientific study and leave out such a confounding factor. This start of Anthony Watts scientific career is deeply flawed.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-67962170408645873222012-08-05T14:11:28.453+01:002012-08-05T14:11:28.453+01:00I am not so sure whether I find the "satellit...I am not so sure whether I find the "satellite argument" that convincing. Satellites have their own inhomogeneity problems, new satellites or even new types of satellites go in and out of the record. And there is not much redundancy (multiple satellites measuring at the same moment) as in the surface record, which helps you to find the inhomogeneities. <br /><br />Furthermore the satellites also do not measure temperature directly, but only retrieve it based on the radiation the satellite receives. Changes in, for example, clouds and aerosols could produce an artificial trend in the satellite record.<br /><br />If there were a difference between the surface network trend and the satellite trend, I would intuitively start search for problems with the satellite data.<br /><br />The satellites are great for investigating problems around temporal sampling and to aid in studies around the Urban Heat Island effect. You can also use them to study regional differences in climate variability and trends. <br /><br />Maybe I am biased, as I know the surface network and its processing better. However, when it comes to the long term temporal behaviour of atmospheric temperatures, I tend to trust the surface record much more.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-1797827169273854892012-08-05T10:43:48.712+01:002012-08-05T10:43:48.712+01:00So, Mogumbo Gono, you are saying this study was pu...So, Mogumbo Gono, you are saying this study was published on the web because of the rivalry between Watts and Muller? Interesting that a "sceptic" himself states that the main aim of the manuscript was not a better understanding of the climate system.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-44942830452796810552012-08-05T04:44:35.775+01:002012-08-05T04:44:35.775+01:00Just in case anyone missed tamino's great resp...Just in case anyone missed tamino's great respont to victor's comment as above at open mind<br /><br />Response: Analyze first, announce later? Take your time and be careful? Devote lots of thought to your results? How radical of you.<br /><br />Perhaps your process is different because your goal is different.]JBnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-54748616515651206142012-08-03T10:48:43.603+01:002012-08-03T10:48:43.603+01:00And now Anthony Watts does it again and promised t...And now Anthony Watts does it again and <a href="http://wattsupwiththat.com/2012/08/02/update-on-watts-et-al-2012/" rel="nofollow">promised that the revised manuscript is finished "in the next day or two"</a>. <br /><br />It would be better if he first finished the analysis, you never know which problems turn up during this. When the analysis is solid, you have read and described all relevant literature and you only want to work on the clarity of the text a bit more, that it the moment you may announce to put a manuscript on the web in a few days. Even in that case, I would wait at least a week, to be able to reread and edit my own manuscript with a fresh mind. <br /><br />Anthony Watts does not seem to be able to learn from past experience.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-82712844893729297332012-08-03T02:26:01.025+01:002012-08-03T02:26:01.025+01:00Horatio does it again
http://tamino.wordpress.com...Horatio does it again<br /><br />http://tamino.wordpress.com/2012/08/01/much-ado-about-nothing/#comment-64997JBnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-40078619889608977702012-08-02T09:35:52.595+01:002012-08-02T09:35:52.595+01:00Removed double comment.Removed double comment.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-52068152715083236332012-08-02T02:40:43.783+01:002012-08-02T02:40:43.783+01:00This comment has been removed by a blog administrator.JBnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-50394776459877878242012-08-02T02:37:59.426+01:002012-08-02T02:37:59.426+01:00OH my Anthony
Speaking of statistics, Watts state...OH my Anthony<br /><br />Speaking of statistics, Watts states that he started teaching himself statistics on Friday afternoon and posted the paper on Sunday afternoon. Overturning a big chunk of climate science in the process.<br /><br />it is becoming painful, but due thanks to Victor for his early and valued appraisal.<br /><br />will follow your blog from now on. John ByattJBnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-37310014523743077762012-08-01T19:59:24.037+01:002012-08-01T19:59:24.037+01:00Thanks anon. That didn't offer a step-by-step ...Thanks anon. That didn't offer a step-by-step but I found this which explains the/a process for doing so.<br /><br />http://www.john-daly.com/tob/TOBSUM.HTMMark Sheadnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-81275330457927610332012-08-01T19:01:59.201+01:002012-08-01T19:01:59.201+01:00No error bars, either, which are quite important i...No error bars, either, which are quite important in determining rate-of-change. <br /><br />Also, the data in this graph cut off in 1950, so, no, it doesn't show the modern warming. This is described in the original paper, which I recommend you check:<br /> "Temperature, accumulation, and ice sheet elevation in central Greenland through the last deglacial transition", by Cuffey and Clow, 1997, JGR.<br /><br />The chart is based on a modification by Don Easterbrook from that paper. Easterbrook's modification can be found here: <br />http://www.globalresearch.ca/index.php?context=va&aid=10783<br /><br />And as Gregor said, Greenland temperatures aren't representative of the entire globe. <br /><br />True skepticism requires carefully checking your sources, the data, and actively looking for ways to disprove your hypothesis. I recommend a bit more skepticism; don't be so quick to accept the first thing you read on the internet.Windchasershttps://www.blogger.com/profile/11554275410734284781noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-67931305861360019692012-08-01T14:00:20.617+01:002012-08-01T14:00:20.617+01:00It's okay to be wrong, but then you should fai...It's okay to be wrong, but then you should fail in an interesting way that helps many scientists to understand the topic better.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-56908134767067985242012-08-01T13:54:03.830+01:002012-08-01T13:54:03.830+01:00Yesterday Steve McIntre of ClimateAudit and co-aut...Yesterday Steve McIntre of ClimateAudit and co-author of Watts et al. admitted that his contribution was made in a hurry and that the missing <a href="http://climateaudit.org/2012/07/31/surface-stations/" rel="nofollow">time of observation bias is a serious problem</a>. <br /><br /><i>People have quite reasonably asked about my connection with the surface stations article, given my puzzlement at Anthony’s announcement last week. Anthony described my last-minute involvement <a href="http://wattsupwiththat.com/2012/07/29/backstory-on-the-new-surfacestations-paper/" rel="nofollow">here</a>. <br /><br />Whenever I’m working on my own material, I avoid arbitrary deadlines and like to mull things over for a few days. Unfortunately that didn’t happen in this case. There is a confounding interaction with TOBS that needs to be allowed for, as has been quickly and correctly pointed out.<br /><br />When I had done my own initial assessment of this a few years ago, I had used TOBS versions and am annoyed with myself for not properly considering this factor. I should have noticed it immediately. That will teach me to keep to my practices of not rushing. Anyway, now that I’m drawn into this, I’ll have carry out the TOBS analysis, which I’ll do in the next few days (at the expense of some interesting analysis of Esper et al.)</i><br /><br />Now also Roger Pielke Sr. <a href="https://pielkeclimatesci.wordpress.com/2012/07/31/summary-of-two-game-changing-papers-watts-et-al-2012-and-mcnider-et-al-2012/" rel="nofollow">distances himself from Watts et al.</a><br /><br /><i>UPDATE #2: To make sure everyone clearly recognizes my involvement with both papers, I provided Anthony suggested text and references for his article [I am not a co-author of the Watts et al paper], and am a co-author on the McNider et al paper.<br /><br />UPDATE: There has been discussion as to whether the Time of Observation Bias (TOB) could affect the conclusions reached in Watts et al (2012). This is a valid concern. Thus the “Game Changing” finding of whether the trends are actually different for well- and poorly-sited locations is tenative until it is shown whether or not TOB alters the conclusions. The issue, however, is not easy to resolve. In our paper</i><br /><br />Also first author <a href="http://wattsupwiththat.com/2012/07/31/watts-et-al-paper-2nd-discussion-thread/" rel="nofollow">Anthony Watts</a> admits that the study was not of high quality.<br /><br /><i>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.</i><br /><br />I would be ashamed if I had produced a manuscript that needed hundreds of suggestions and corrections. I would take a holiday, analyze how this could happen and whether I should stay in science.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-86801633440164041252012-08-01T13:37:18.256+01:002012-08-01T13:37:18.256+01:00Thank you, I just wanted to add AGW observer link ...Thank you, I just wanted to add AGW observer link to this page.<br /><br />For those of you that can read German, there are two studies going back to 1848 on the time of observation bias. Well before climate change became a political issue.<br /><br />Kreil K, 1854a. Mehrjährige Beobachtungen in Wien vom Jahre 1775 bis 1850. Jahrbücher der k.k. Central-Anstalt für Meteorologie und Erdmagnetismus. I. Band – Jg 1848 und 1849, 35-74.<br /><br />Kreil K, 1854b. Mehrjährige Beobachtungen in Mailand vom Jahre 1763 bis 1850. Jahrbücher der k.k. Central-Anstalt für Meteorologie und Erdmagnetismus. I. Band – Jg 1848 und 1849, 75-114.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-34984784728256312562012-08-01T13:05:52.641+01:002012-08-01T13:05:52.641+01:00Courtesy of AGW Observer: Papers on time of observ...Courtesy of AGW Observer: <a href="http://agwobserver.wordpress.com/2012/08/01/papers-on-time-of-observation-bias/" rel="nofollow">Papers on time of observation bias</a> (going back to 1890).J Bowersnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-21726424195793003512012-08-01T10:32:07.025+01:002012-08-01T10:32:07.025+01:00Good you found it. That would be exactly my answer...Good you found it. That would be exactly my answer.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-80017834513539881892012-08-01T10:31:17.435+01:002012-08-01T10:31:17.435+01:00Dave, you will have to ask at ClimatePrediction. A...Dave, you will have to ask at ClimatePrediction. As far as I know they are studying the sensitivity of Climate models to perturbations in the model constants and structure. For that you do not need any empirical measurements. For validation of the models you do and to determine the initial atmospheric state in case you want to make a prediction.Victor Venemahttps://www.blogger.com/profile/02842816166712285801noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-20178243055900668352012-08-01T09:05:45.006+01:002012-08-01T09:05:45.006+01:00The USHCN Version 2 Serial Monthly Dataset page:
...The USHCN Version 2 Serial Monthly Dataset page:<br /><br />http://www.ncdc.noaa.gov/oa/climate/research/ushcn/Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-14322000605856839412012-08-01T08:37:23.124+01:002012-08-01T08:37:23.124+01:00Fascinating arguments. I found this through a link...Fascinating arguments. I found this through a link on Climateprediction.net Out of interest does anyone know if these data sets go into the climate models that my computer is busy crunching?<br /><br />DaveUnknownhttps://www.blogger.com/profile/00170874688944278502noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-53725152120584862352012-08-01T08:02:03.516+01:002012-08-01T08:02:03.516+01:00There is one example, how much TOBS matters. I cal...There is one example, how much TOBS matters. I calculated daily lows and highs for Ljubljana, central European city with temperate climate.<br /><br />Mean highs and lows (°C) from the automated station in the period of 2002-2011 are as follows (end time of 24-hour period is given):<br /><br />7 a.m. local (solar) time: 16.1 / 6.7<br />12 a.m.: 16.5 / 7.2<br />7 p.m.: 16.4 / 7.2<br />9 p.m.: 16.3 / 7.1 <br />12 p.m.: 16.2 / 6.9<br /><br />9 p.m. time of observation is used in Slovenian climate network, observers read both minimum and maximum daily extremes at that time. If we join observer's data series of Tmin and Tmax with the automated station series, we need to be careful to properly account for possible TOBS change.<br /><br />Corrections of TOBS bias are also site-specific as the diurnal range may be very different from location to location.Gregor Vertacniknoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-7610870342717329502012-08-01T07:57:21.271+01:002012-08-01T07:57:21.271+01:00Found it as one of your comments, thanks Victor
T...Found it as one of your comments, thanks Victor<br /><br />The increase in the temperature trend is thus not due to adjustment of stations with a low trend to the ones with a strong trend, but due to the change in the way the temperature is measured, the transition from LiG to MMTS and also probably due to a change in the time of observationJBnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-65045055655084705262012-08-01T05:37:51.938+01:002012-08-01T05:37:51.938+01:00"...my guess is you're putting too much f..."<i>...my guess is you're putting too much faith in TOBS here</i>"<br /><br />Why guess? <br /><br />There's work that's been done to justify accounts for time-of-observation bias. Why not assess it, and if you detect a flaw, counter it?<br /><br />Or are you just trying to shoot at the side of the barn?<br /><br /><br />Bernard J.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-73169162632196004692012-08-01T05:04:30.202+01:002012-08-01T05:04:30.202+01:00Rattus, my guess is you're putting too much fa...Rattus, my guess is you're putting too much faith in TOBS here. There are other issues as well, one of these (a change in mean latitude over time of the reporting stations) leads to an effect with the <i>opposite</i> bias.<br /><br />When you are dealing with complex phenomena, it's best not to put all your eggs in one basket. [It's also BEST not to rush your papers out to meet the deadline for AR5.]Carrickhttps://www.blogger.com/profile/03476050886656768837noreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-24375402486143613262012-08-01T04:00:49.025+01:002012-08-01T04:00:49.025+01:00I returned to post again and re-read my prior post...I returned to post again and re-read my prior post to find that my choice of wording was somewhat confusing. I meant, "I would prefer to read an official NOAA document which states Preferred Time for Taking Observations of temperature stations specifically (as opposed to precipitation stations which may or may not also be temperature stations.)"<br /><br />I had assumed that time of observation adjustments were done to normalize temperature readings to a specific time-of-day-temperature across all stations. However from what I am reading it appears that it is only used to normalize time-of-observation-temperatures for a specific station when time-of-observation has changed for that particular station? That doesn't seem correct but I can't find anything to refute it.<br /><br />In other words, a specific station's data is recorded at 7am daily for 10 years then it changes to 8am daily for ten years and TOBS corrects for the different time used in one of the 10 year periods but the adjustment is only for that specific station and no TOBS adjustment is made to compensate for a different station which was always read at 9pm despite 9pm being significantly different than 7 or 8am? <br /><br />And I'm most curious of all about why a web search for "how to adjust temperature for time of observation" does not immediately lead to a clear, step-by-step list of instructions as to how TOBS adjustments are (or should be) calculated? Is there any official (or widely accepted) procedure?Mark Sheadnoreply@blogger.comtag:blogger.com,1999:blog-9093436161326155359.post-81273947578096733752012-08-01T03:01:42.875+01:002012-08-01T03:01:42.875+01:00As the discussion of the effect of the TOBS adjust...As the discussion of the effect of the TOBS adjustments here has shown, applying TOBS results in consistently cooler temps in the past. This results in higher trends in stations which require it (and most do).<br /><br />As they say, RTFR (read the FINE reports).Rattus Norvegicushttps://www.blogger.com/profile/03449457204330125792noreply@blogger.com