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Post by magellan on May 7, 2009 3:48:36 GMT
Just to keep this thread alive on occasion so warmers can remind us how great the surface station network is. cat.inist.fr/?aModele=afficheN&cpsidt=2722643The urban heat island of San Antonio, Texas (USA) Résumé / Abstract A study of the urban heat island effect was carried out comparing 45-year daily temperature records (1946-1990) of San Antonio, Texas (USA), with three small surrounding towns; New Braunfels, Poteet, and Boerne. These towns are all within 40 kilometers of San Antonio and were chosen because they form a nearly equilateral triangle around the city from northeast to south to northwest, respectively. The study shows that, on average, the minimum temperatures at the San Antonio International Airport (the location of the weather station) are increasing at an average rate of about 0.3°C per decade relative to surrounding small towns with similar elevation. The difference in minimum temperatures is most pronounced during the summer months. The summer temperature minimum differences relative to New Braunfels indicated the largest increase at 0.4 ± 0.1°C per decade and an increase of 0.2 ± 0.1°C per decade relative to Poteet. In 1947, the minimum temperatures in New Braunfels were on average about 0.2°C warmer than San Antonio and they were about equal between San Antonio and Poteet. In 1990, summer minimum temperatures were more than 1.7°C cooler in New Braunfels and more than 1.0°C cooler in Poteet. A similar trend in the minimum summer temperatures is seen in comparisons with Boerne but the magnitudes are smaller and there are larger temperature fluctuations in the data. This may be due to the higher elevation of Boerne (about 700 meters above see level) whereas San Antonio, New Braunfels, and Poteet all have similar elevations (about 200 meters above see level). The same effects are found in the maximum temperatures in the winter months for New Braunfels and Poteet. They are increasing at average rates of about 0.8°C per decade compared to New Braunfels and 0.5°C per decade compared to Poteet in the winter months. No statistical change in the winter maximum temperatures between San Antonio and Boerne was found. Despite many mitigating influences (e.g., much vegetation, little polluting industry), it has been shown that San Antonio has an increasing urban heat island effect.
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Post by sigurdur on May 7, 2009 12:00:45 GMT
I find the debate about UHI quit amazing in fact.
I am a farmer, and even in my yard the thermometer reading is about worthless when I am checking for near freezing temps that affect my crops. The only true reliable method is to put a thermometer in the FIELD. I have had temp variations of over 3F near freezing. The yard will show a low of 34F, yet the thermometer in the field will show 31F. My yard is NEVER as cold as it is in the total open, and it is always hotter than it is in the total open. Now magnify that with even more buildings etc. and anyone who denies the UHI effect forgot to eat breakfast, dinner and even supper.
And all this bs about correcting for the UHI. HOW do you even begin to "correct" it. The only correction is to move the sensors to remote areas that are NOT influenced by UHI. I know that is hard for AGW people to do as it would show their data to be as full of bs as it really is.
I do know one thing. We NEED to warm another 2-3C to benifit mankind, but sadly, it appears that that is not going to happen.
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Post by socold on May 7, 2009 19:02:57 GMT
Once again skeptics (deliberately?) confuse UHI affecting temperature at a location at point in time with UHI explaining a rising temperature trend over many decades at that location.
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Post by nautonnier on May 7, 2009 20:26:44 GMT
Once again skeptics (deliberately?) confuse UHI affecting temperature at a location at point in time with UHI explaining a rising temperature trend over many decades at that location. Well that all depends. If you use a nice simple Lights=0 then I would contend that you could get a nice continual warming of the type you talk about by an annual change ... Lights=1 Lights=10 Lights=100 Lights=1000 Lights=10,000 etc They all are Lights not equal to zero but perhaps the size and type of conurbation needs to be considered too. It all depends on how simplistic your corrections are - and also on things like are they factory lights, street lights, interstate lights, smelting mill lights, refinery lights etc. Perhaps you can provide some assurance that the 'corrections' are not that simplistic
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Post by magellan on May 28, 2009 22:17:10 GMT
Once again skeptics (deliberately?) confuse UHI affecting temperature at a location at point in time with UHI explaining a rising temperature trend over many decades at that location. Well that all depends. If you use a nice simple Lights=0 then I would contend that you could get a nice continual warming of the type you talk about by an annual change ... Lights=1 Lights=10 Lights=100 Lights=1000 Lights=10,000 etc They all are Lights not equal to zero but perhaps the size and type of conurbation needs to be considered too. It all depends on how simplistic your corrections are - and also on things like are they factory lights, street lights, interstate lights, smelting mill lights, refinery lights etc. Perhaps you can provide some assurance that the 'corrections' are not that simplistic The Hansen 'Lights=0' to determine adjustments in temperature due to land use change, microsite issues and land use change is completely useless. Consider that <100,000 population is considered "rural". Perhaps socold has never stepped onto a parking lot and notice it actually does get warmer where many of the thermometers are placed. Even with empirical data folks like socold will still keep the faith. Anyway, now the Obama administration is proposing to paint the world white to save it ;D www.timesonline.co.uk/tol/news/environment/article6366639.eceIt must be true because Steven Chu is the smartest man on the planet to ever assume the position of Energy Secretary.
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Post by socold on May 28, 2009 22:33:49 GMT
You haven't presented any "empirical data". Why do skeptics so often mistake baseless arguments for empirical data?
Simply claiming that light is not a signal of urbanization sounds more like a dogmatic assumption.
It doesn't have to be right in every situation, it only has to be generally correct in order to weed out the pattern of UHI contamination.
As it is however, the places on Earth that show the most warming are actually not urbanized.
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Post by magellan on May 29, 2009 0:15:06 GMT
You haven't presented any "empirical data". Why do skeptics so often mistake baseless arguments for empirical data? Simply claiming that light is not a signal of urbanization sounds more like a dogmatic assumption. It doesn't have to be right in every situation, it only has to be generally correct in order to weed out the pattern of UHI contamination. As it is however, the places on Earth that show the most warming are actually not urbanized. Of course you can provide the evidence that shows most warming is not in urbanized areas. Lights=0 again? Would you care to explain why the tropics don't exhibit warming compared to higher latitudes? Before sticking your proverbial foot in the mouth, keep in there is data available of the Arctic and Greenland. 50 thermometers placed about a small town of 4500 (considered rural Lights=0) is about as empirical as it gets wouldn't you agree? Many more where this comes from. www.geography.uc.edu/~kenhinke/uhi/Hinkel&Nelson_JGR-A_2007.pdfNot one single article you've used is based on even a visual inspection of the surface stations or determining if the USGHCN or GHCN meet siting standards. That is because there never has been any calibration or maintenance performed to any standard. Anthony Watts took it upon himself to catalog the conditions and siting of surface stations, resulting in ~70% failing to meet even the basic requirements. You may not like that, but no amount of hand waiving by Jones, Peterson or Parker will improve it. As a side note, what would make anyone think satellites don't pick up urbanization and land use change effects? This is not to be confused with micrositing issues.
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Post by dopeydog on May 29, 2009 0:24:07 GMT
UHI is one result of many land use activities by man that can raise local and regional temperatures. Dumping billions of acre feet of water onto deserts and dry areas like central California every year, raise temparatures by adding water to the atmosphere. Water is a green house gas.
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Post by magellan on May 29, 2009 0:59:39 GMT
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Post by glc on May 29, 2009 9:30:52 GMT
It is also referenced here: www.mma-web.org/UserFiles/File/ChristyJR_MS_081002.pdfExcellent. I can use this link in response to response to most arguments. Please read Page (Slide) 8, particularly the last 2 points which are Surface temperatures response to 2xCO2 (alone) is ~1 C The associated feedbacks are where the uncertaintities are large (i.e. no confident numbers)
Exactly what I 've been saying consistently throughout the last few months. And for those of you who have assumed that Steve, Socold and me are of the same opinion - Christy's statements summarise THE difference. There is high confidence that increasing levels of CO2 will cause the world to warm. The argument concerns feedbacks.
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Post by magellan on May 29, 2009 11:15:18 GMT
It is also referenced here: www.mma-web.org/UserFiles/File/ChristyJR_MS_081002.pdfExcellent. I can use this link in response to response to most arguments. Please read Page (Slide) 8, particularly the last 2 points which are Surface temperatures response to 2xCO2 (alone) is ~1 C The associated feedbacks are where the uncertaintities are large (i.e. no confident numbers)
Exactly what I 've been saying consistently throughout the last few months. And for those of you who have assumed that Steve, Socold and me are of the same opinion - Christy's statements summarise THE difference. There is high confidence that increasing levels of CO2 will cause the world to warm. The argument concerns feedbacks. Before you get too giddy, it may be efficacious to be familiar with all his research
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Post by dopeydog on May 29, 2009 12:04:18 GMT
Also keep in mind that temperature increase assumes no feedback. Negative or positive.
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Post by socold on May 30, 2009 1:39:13 GMT
You haven't presented any "empirical data". Why do skeptics so often mistake baseless arguments for empirical data? Simply claiming that light is not a signal of urbanization sounds more like a dogmatic assumption. It doesn't have to be right in every situation, it only has to be generally correct in order to weed out the pattern of UHI contamination. As it is however, the places on Earth that show the most warming are actually not urbanized. Of course you can provide the evidence that shows most warming is not in urbanized areas. Lights=0 again? The arctic and western antarctic peninsula show the most warming. Those are hardly urbanized areas. Additionally of lesser warming areas, a large amount is over the oceans, again not urbanised. and the lower troposphere, which as far as I know doesn't contain any cities. Why should they? If you are talking about the mid troposphere then this doesn't have anything to do with UHI anyway for obvious reasons. Compared to a busiling city of 450,000 yes it is rural. The whole point is to get a statistical pattern of urbanization and see how the temperature is affected by locality to more urbanized areas. Watt's has gone down the root of weeding out bad stations by visual inspection. Hansen went down the route of weeding out the bad stations by statistical analysis of the temperature data. Both arrive at the same conclusion.
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Post by tacoman25 on May 30, 2009 19:23:30 GMT
Of course you can provide the evidence that shows most warming is not in urbanized areas. Lights=0 again? The arctic and western antarctic peninsula show the most warming. Those are hardly urbanized areas. The Arctic does NOT show the most warming over the past 100 years, however. It has warmed more over the past 30 years, but it also cooled more than most of the globe in the 50s - 70s. Arctic temperatures fluctuate more than most regions.
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Post by icefisher on Jun 1, 2009 19:56:43 GMT
It is also referenced here: www.mma-web.org/UserFiles/File/ChristyJR_MS_081002.pdfExcellent. I can use this link in response to response to most arguments. Please read Page (Slide) 8, particularly the last 2 points which are Surface temperatures response to 2xCO2 (alone) is ~1 C The associated feedbacks are where the uncertaintities are large (i.e. no confident numbers)
Exactly what I 've been saying consistently throughout the last few months. And for those of you who have assumed that Steve, Socold and me are of the same opinion - Christy's statements summarise THE difference. There is high confidence that increasing levels of CO2 will cause the world to warm. The argument concerns feedbacks. You are investing in a false sense of security there GLC. The 1C warming from a doubling of CO2 is not controversial because it portends no significant impact. Non-controversial can mean any of two things, either its right or its unimportant even if it is right. Most people in reviewing/peer reviewing/auditing etc. tend to focus only on stuff thats important. Or at least they do in the accountable world where results are supposed to be both useful and inexpensive. Its clear adding any gas to the atmosphere is going to create the potential for warming. Thats a given. But it doesn't answer the question as to whether it is important or not or whether it actually results in on the ground warming of any significant degree. It seems that Christy and Spencer both agree the warming could be as much as 1 degree C as a potential. Whether they agree with that is because they have carefully reviewed it or merely accepted it as a presumption unworthy of sufficient review is not clear. Whether it is that or more or less depends upon whether feedbacks are positive or negative and to what degree those feedbacks add to or subtract from the actual warming realized. Only with this issue does the AGW theory become important.
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