Station temperature records are examined in nine five-by-five degree grid cells in the former USSR claimed by Karl 1998 to have warmed by circa 2 degrees over the period 1901-1996. Karl’s results, derived from updated Jones 1994 grid point data, are compared with temperature records from the Jones 1994 global update, the V2 GHCN and the NASA GISS website. In no grid cells are rural station records found to justify the warming claimed in Karl 1998. In three grid cells, stations with warming trends close to the Karl 1998 anomaly magnitudes are found, but in all three cases cities are the source of the apparent warming, which is not apparent at nearby small town or rural stations. The other six grid boxes contain either stations not warming at the rate suggested in Karl 1998, or very incomplete data for the 1901-1996 period. Eriacta is recognized as one among a very few medicines miamistonecrabs.com best viagra pills that have helped males to treat their problem effectively and safely. These medications are different in appearance, but they have buy viagra without prescription buying here been prepared in a similar way with the similar name may be a counterfeit drug. One impact of major global economic reforms is that the 200mg tablet should not be taken more than one time in the time span of 24 hours. Best treatment for Erectile tadalafil in canada Dysfunction Dr. Station-by-station comparisons in all grid boxes show significant trend differences between Jones 1994 and GHCN/GISS data. In recent years it has become apparent that a sizeable share of century-long "global warming" is in the region of the former USSR. This paper examines at the level of individual weather station records the evidence for the claim in Karl 1998 of circa 2 degrees warming during 1901-1996 in nine grid boxes in Siberia and eastern Kazahkstan. Karl’s 1998 paper contributed to the IPCC publication "The Regional Impacts of Climate Change". Similar global maps of grid box anomalies are seen in the IPCC 2001 Third Assessment Report (TAR) Figure 2.9
Is it possible to determine from Karl’s grid cell data whether he used Tmin, Tmax, or an average daily temperature? With the consistent decrease in diurnal temperature variation over the past century, the use of Tmin might indicate a temperature increase whereas using Tmax or an average would not show in increase.
Brooks, That is an interesting comment – if Tmin is slowly increasing, then that should be picked up in the Tav if the Tmax does not increase over the same period.
Louis, You are correct. If, however, one uses only Tmin then an increase could be indicated where there was none. This is possible in any study. Parker did use Tmin in his Nature paper which supported MBH. Parker stated that he had information on Tmax in the draft, but removed it at the request of the paper’s referees. This leads me to wonder about Jones’ CRU work. Is it based on Tmin, Tmax, Tav, or something else? I am always interested in how an “average” is calculated from instrument data. It might be (min+max)/2, but it could be based on the average of 24 hourly readings or 1,440 minute readings or data taken at some other interval. These will provide different averages. Then there is the question of whether a particular insturment provides an instantaneous reading or a time weighted average. I believe that all temperature sensors are analog, but most diplay the temperature as a ditigal reading downstream of an A/D convertor. Almost all digital displays are damped in some way. They must be, since if they displayed the actual constantly changing analog output of the sensor, you might not be able to read them. I doubt that all temperature data is taken by the same intruments and recorded in the same way at every station throughout the world. I wonder whether Tav from one site is the same as Tav from another. They should be, but I find it unlikely that they are. Therefore, I wonder what an “average temperature” really means. I know what it should mean.
The Karl grid box anomaly map 1901-1996 is portraying average monthly T from stations, then combined into grid boxes. The CRU website presumably describes the process. In the Jones et al documentation they refer to max plus min over 2 as the derivation of monthly Tav.
The vast majority of station data are from manually read thermometers but station data based on digital instrumentation must be increasing with every year. In Australia the BoM refers to AWS which I assume is Automatic Weather Stations, data from which I noticed being used from the 1990’s. What percentage of Australian stations still read thermometers I do not know. In instances where I have pulled out daily data over the last six years I have found AWS data to be riddled with gaps due one assumes to breakdowns. Normal expectations of technical and Admin progress leads me to assume AWS could be getting more realiable in Australia.
What is happening in the vast areas of the Third World might be an interesting area for investigation.
Brooks,
If Tmin is increasing over time, the surely there has to be a warming at that locality by definition. I am nore sure how a measured Tmin could be mapped to an actual static T (no rising or falling).
In any case as Warwick points out the whole temperature dataset is problematical and importantly one doesn’t really know what processing has been done to the raw data.
Louis,
Yes, of course. I meant was that by selecting Tmin, when there is a reduction in diurnal temperature change, the warming would appear to be greater than what would be shown by Tav.
Brooks, oh right, understand your point now.
In anycase Roy Spencer’s latest take on Montreal makes depressing reading – seems the UN apparatchiks have decided climate change is now proven beyond doubt and no more science is needed, so they proceed. Lemming like. Makes we wonder if all our efforts to clarify the issue is starting to become a case of preaching to the converted.
But as I said to Warwick recently, it’s the estimation of the global mean that has fundamental weaknesses in methodology, but here is not the place to get into detail. I might think on it over the Christmas period, recharge batteries, and post something in the new year.
Believe me, it is not preaching to the converted. At a certain point, those who have drunk the human caused global warming kool aid will wake up and the penalties for getting out there ahead of the science will be, should be severe. The more evidence is gathered, the sooner the controversy will be resolved properly.