Comments on: Reliability of Surface Temperature Records

By: Jim

Jim — Sat, 16 May 2009 16:45:33 +0000

An Inq: Thanks for the clarification. I was aware that different equipment is used at various sites and also of the time of day problem. The fact that time of day of the measurement is critical is obvious and some kind of correction must be made. I am with you on the satellite data, they are the best, truly global temperature measurements we have. I am disturbed at attempts to stretch sparse measurements over the globe to read the T trend, as well as things like Steig’s analysis of the Antarctic temperature trend. It appears to me that sometimes you just have to accept the fact that there isn’t enough data to draw a global or continent wide conclusion and live with it. I am also disturbed when researchers make up new statistical techniques that have not been vetted by the wider scientific and mathematical community. I am more of a doubter than denier. But one thing’s for sure – the debate is not over.

By: An Inquirer

An Inquirer — Sat, 16 May 2009 15:55:22 +0000

Jim, the problem is not just with UHI. The problem is also with micrositing issues such as locating the station next to exhaust from air conditioning units — and air conditioning was not there 60 years ago. In many places, the thermometers have been moved closer to buildings. Even if the buildings are in rural areas, they still give off heat. Many great examples, but I needed to laugh at one example in rural Alaska — next to the electric coop with plenty of heat being given off.
What Anthony Watts has done is try to find quality stations that have minimal local siting issues.
Perhaps very few people realize that the raw, unadjusted data shows that U.S. temperatures are no higher now than they were in the 1930s. However, the official keepers of the record feel that we need to make adjustments for Time of Observation and other issues. The methodology of collecting data has changed, and so programs have been developed to make adjustments for this. The TOBS adjustment process is not without controversy, but the graphs produce do have those adjustments.
For these and other reasons, the satellite data offers an attractive alternative. However, this data goes back only 30 years; a period over which we have been in positive phases of PDO and AMO, and we would expect an upward trend. One issue that is completely ignored by GW pessimists is that satellite temperatures over oceans (no UHI) is no higher now that it was 30 years ago.

By: Jim

Jim — Fri, 15 May 2009 00:11:56 +0000

An Inq. – IMHO, the stations that are affected by UHI should just be discarded as tainted. I believe the raw data is available. It would be interesting to create a grid over the US, find the rural stations within each grid, check each rural station for anomalies, throw out anomalous readings (not the entire station), get the monthly average temps of the rural stations within the grid, then average them all together to get a monthly chart. Hopefully, there would be enough rural stations to uniformly cover the country. I guess if there were not, one could make the grids bigger, to a point.

By: An Inquirer

An Inquirer — Wed, 13 May 2009 03:05:21 +0000

Jim, I am not aware of any study that you describe. Indeed, it might be tough in the USHCN network to get 50 quality stations outside of “heat biased” areas. One work by David Archibald may interest you — his March 2008 paper that studies the average of four rural stations since 1893. If you add to his study other stations that I know are out of UHI, you would get the same result. Reference: http://www.davidarchibald.info and select the March 2008 paper. Of course, some could argue that his graph is an illustration of what you can do by cherry-picking. However, I do not think you can dismiss his work that easily. Look for stations on the various continents that are not affected by UHI or local site issues, and my examination of them shows the same trend. Lest anybody gets excited that we have clarity on the issue of long range temperature trends — we don’t. Satellite data agree that there has been a positive trend from 1979 to the early 2000s. Of course, that was during positive phases of PDO and AMO, so reasonable people can disagree.

By: Jim

Jim — Wed, 13 May 2009 00:48:35 +0000

Has anyone surveyed, say, 50 stations where there is heat bias vs 50 stations relatively close, but not within the heat biased area? Also, distributed across the US so as to be somewhat representative?

By: An Inquirer

An Inquirer — Tue, 12 May 2009 22:53:13 +0000

MikeC:
I think you are unduly harsh with JohnV’s work. It is widely recognized that he did not have a statistically significant sample size to make any valid claims; however, he is recognized as honest, and he did make his data & work publicly available. That later move is quite rare in the AGW camp — of course, it was not his data; it was the data that Anthony Watts had made available. There have been some criticism of John V’s work, and certainly when he used CRN 3 stations, that undermines his point that GISS adjusted trends follow high quality stations. Nevertheless, I do not see how you can call it a lie. Yes, there was poor geographical distribution, but I do not understand your complaints missing adjustments, closures & recent equipment changes. If I understand you correctly, CRN 1 & 2 should not have these issues.

By: MikeC

MikeC — Tue, 12 May 2009 19:00:43 +0000

This whole JohnV thing is a lie. JohnV used 17 stations with poor geographical distribution and without complete adjustments (agricultural and box construction bias, for example). Many of the stations were closed or had recent equipment changes. Very few actually met the criteria for the entire time period. When he could not get enough category 1 and 2 stations that were not located in Urban areas he started using flawed stations (3′s).

By: Steve

Steve — Fri, 08 May 2009 05:10:10 +0000

Did any one watchthe TV program titled (I think) “raising the baby mamoth”. Any way, the baby was located in ice now but when it was burried there wasn’t permafrost there. The location is in northern Siberia and the baby was dated at 40,00 years old. The baby was to well preserved to have been uncovered by thawing as a result of warming. She was only just starting to become uncovered by surface errosion and most of her was still in ice. My point is that 40,000 years ago a baby mamoth was in a location that is currently Arctic snow and ice where it is possible for only the hardiest of winter animals can survive. It doesn’t look like we will have the conditions at that location that a baby anything will survive unless global warming actually does ake place (which I think is only temporary). I would love to be able to go outside here in the 4 corners area of the US in short pants and tee shirt in February so until then I won’t worry about gloabal warming to much.

By: Jim

Jim — Thu, 07 May 2009 00:27:55 +0000

I’m not upset that humans are changing the planet. We are, after all, just as natural as the blue-green algae that began spewing toxic oxygen into the atmosphere a few billion years ago. If we are going to change it in such a way that kills us off, I would be concerned, but otherwise – change is the way of the universe.

By: An Inquirer

An Inquirer — Wed, 06 May 2009 20:05:16 +0000

Kuhnkat, thank you for your attempt to increase understanding of statistics. I am reminded of a past discussion with a GW pessimist in which I opined that for chronological GMT series a polynomial fit might be better than OLS for a linear fit. I thought I had a great analogy. If in mid-1944 you did a linear fit of German vs. Russian military success, you would give the future to Germany. However, if you did a polynomial fit, you would get a better handle on the future. His response was that “we are talking about temperature, not about armies whose fortunes can rise or fall on a single battle. Ah, it is better sometime to go to bed rather than to straighten out everybody on the internet who is “wrong.”