Since BEST claims they will work to take UHI into consideration, it seems worthwhile to highlight this new paper. Guess who’s a co-author? Phil Jones of UEA’s CRU.
From Dr. Roger Pielke Sr.:
New Paper “Decadal Variations In The Nocturnal Heat Island Of London” By Wilby Et Al 2011
There is a new paper that adds significantly to our understanding of the urban heat island, and thus its role on long-term surface temperature records. The new paper is
Robert L. Wilby,Philip D. Jones and David H. Lister: Decadal Variations In The Nocturnal Heat Island Of London. Weather March 2011. DOI: 10.1002/wea.679
The abstract reads
“Our review of the long-term behaviour of London’s UHI provides a salutary reminder that the appearance and disappearance of trends in environmental data can depend very much on the segment of data analysed. Nonetheless, we can confirm – using both daily and monthly temperature records – that the summer nUHI did intensify between the late 1950s/early 1960s and the 1980s. This period coincided with an abrupt increase in the frequency of summer anticyclonic weather. There is also evidence of a slight rise in the annual number of intense heat-island events that can be linked to more persistent anticylonic weather systems at that time. A weak decline in summer nUHI since the 1980s coincides with a rise in the frequency of cyclonic weather. Since 1931, the summer nUHI has risen slightly, but not significantly. The overall annual mean nUHI does, however, show a weak but significant (p<0.05) rise when the monthly SJP record is compared to that of WIS.”
Their concluding remarks read
Our review of the long-term behaviour of London’s UHI provides a salutary reminder that the appearance and disappearance of trends in environmental data can depend very much on the segment of data analysed.
Nonetheless, we can confirm – using both daily and monthly temperature records – that the summer nUHI did intensify between the late 1950s/early 1960s and the 1980s. This period coincided with an abrupt increase in the frequency of summer anticyclonic weather. There is also evidence of a slight rise in the annual number of intense heat-island events that can be linked to more persistent anticylonic weather systems at that time. A weak decline in summer nUHI since the 1980s coincides with a rise in the frequency of cyclonic weather. Since 1931, the summer nUHI has risen slightly, but not significantly. The overall annual mean nUHI does, however, show a weak but significant (p<0.05) rise when the monthly SJP record is compared to that of WIS.
Over the 50-year daily record, less than half of the variance in the summer-mean nUHI signal is explained by synoptic weather patterns. This could be due to a number of factors. The weather types describe conditions across the British Isles generally, rather than for southeast England specifically. The conditions experienced within a given weather class are known to vary from day to day. There have also been marked changes in regional air quality in the wake of the notorious winter ‘smogs’ of the 1950s and the summer stubble burning
of the 1970s and 1980s. Other time-dependent factors (such as artificial heat sources, building albedo, thermal mass, sky-view factors, surface roughness, and vegetated area) may be locally important (McGregor et al., 2006). Furthermore, censuses show that the population of Greater London peaked in 1939 then fell until 1991 and has since risen again.”
This paper is an important new addition to the literature on multi-decadal surface temperature trends.
==============================================================
Here’s the first page of the article from Wiley publishing:
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Hmmmm
I’m thinking the entire so called 20th century slight warming is primarily due to UHI.
That’s a start on a running retreat IMHO,
According to the website linked below, Wisley has the highest july temp for the UK (2006). If you really wanted an urban station in London, you’d pick Camden Square, which holds a number of record highs including for April and May.
http://www.torro.org.uk/site/maxtemps.php
The suitability of Wisley as a “rural” station could be debated. You can find its location on Google earth (search wisley, surrey; station is south east of the weird swirly garden).
London’s population is still 500,000 less than 1938 despite taking up three times more space and having the second largest influx of immigrants in the world, first being the US.
He came close but Jones just couldn’t bring himself to say that overnight minimum temperatures are not a good metric for identifying global warming trends.
Is Jones going to lose the data for this one like he did for his 1990 Nature report on UHI?
Mike’s Nature Trick “Hide the Decline”
Phil’s Nature Trick “Lose the Data”
James ibbotson says:
April 2, 2011 at 10:18 am
I’m thinking the entire so called 20th century slight warming is primarily due to UHI.
That’s a start on a running retreat IMHO…
___
Not likely.
I wonder what the satellite map would have looked like in the 1930’s.
Another factor often overlooked is the effect of smog. (My mum told me I nearly died in the Great London Smog of 1952 when I was a baby). Daytime temperatures would have been lower when smog was around although I am not sure what the effect would have been at night.
I wondered what Dave Lister had been doing since Red Dwarf.
This is a good one, I hope, and a genuine contribution to actual climate SCIENCE. Ironically, Phil Jones had made his original repution on UHI. He has now an opportunity to repolish his image and that of his university, by dropping all mouthing of globull warming and increasing our understanding of UHI, a real (and often beneficial) phenomenon.
It is a lot of fun to sneer at idiots and you wonderkinder here do a magnificent job of it and I laugh my head off at your comments. But human progress is not really made by slamming people. This Phil Jones has been bruised (his fault, but we all screw up). He needs encouragement and this is just the thing to congratulate him on.
Thank you, Anthony. and Dr. Pielke.
There is a 7 ° F difference between downtown Dallas and the surrounding countryside at about sundown on a clear summer day. I have measured it myself. I have a temperature recording thermometer [bought from this site] and started in downtown Dallas and drove the speed limit out to the country 35 miles away.
The “correction” applied to the closest site of record [DFW airport] has been about + .5 ° C which is the wrong direction ! It makes the temperature is Dallas even warmer.
I don’t know why the raw numbers are too low because the buildings runways and a small city which has sprung up around there since 1977 have to have raised temperatures due to UHI !
“Since 1931, the summer nUHI has risen slightly, but not significantly. The overall annual mean nUHI does, however, show a weak but significant (p<0.05) rise when the monthly SJP record is compared to that of WIS."
They acknowledge the principal existence of UHI but say it doesn't contribute much; so, "here, that's handled, now stop bothering us with UHI". Nice try.
But we know that GISS exploits UHI in a very clever way.
http://www.warwickhughes.com/blog/?p=753
The thing I find interesting is from the thermal image that has been placed at the head of this piece. If that is a representative photograph then St James’s Park is at least 4 degrees cooler than the bulk of London. This would indicate that this is not a good site to demonstrate UHI in the city. I understand the need for long series of data but I would have thought there must be other, if shorter, series that would be more appropriate.
Does anyone know the precise location of the monitoring station?
“Our review of the long-term behaviour of London’s UHI provides a salutary reminder that the appearance and disappearance of trends in environmental data can depend very much on the segment of data analysed.”
Phil is undergoing a slow rebirth. This reminder that cherry picking start dates for your trends can give you whatever you want. Phil had a career near-death experience over the past year and a half since climategate but seems to be recovering. I had to grudgingly admire his statement back then that there had been no statistically significant warming since 1995 and I believe we can look forward to more science-based work from him.
This is a lot different than the dogged persistence with attempts to salvage some semblence of the hockey stick and the woeful tree ring circus by the bunch that prefer to remain under seige. Probably Pachari is secretly shoveling the snow off the Himalayas, too. Schneider and Ehrlich – former new-ice-age fanatics morphed into CAGW zealots in a few years. Meanwhile CAGW has diminished to AGW, then to climate change, to climate disruption and what? Climate ripples as cooling continues sealevel begins to peak.
London is an old well established city. Reading the screen shot of the 1st page of the paper, one of the things the author’s point out, is that the temperature increase, since 1907, has been the same for the rural and urban stations that were studied.
I don’t believe that Jones ever denied the reality of the UHI. What he and the other scientists studying the global temperature record try to do is eliminate any bias from the UHI from the temperature record.
Jit,
Fair comment about the Wisley met station being not exactly rural – those structures 20m away are large polytunnels, covering several hundred square metres. On hot days these will be ventilated by opening the ends (and possibly sides) to dissipate the awesome 50 deg. C+ that they’d otherwise contain. I’d suspect that this huge heat source is within a range that might impact on those thermometers.
Hello R. Gates,
I realize you often find yourself in a bit of contention with the other locals here. Kudos to you for taking the time to voice your views and taking (perhaps welcoming!) the criticisms in this arena.
In a recent exchange, you mentioned some issues relating to the onset and progression of ice ages. I find this area particularly interesting. I am not a formally trained meteorologist or climatologist, but just someone who is fascinated by all this ‘stuff’–perhaps the more so because I grew up in southeastern Wisconsin, an area heavily influenced by the last ice age.
I’m skeptical of the accuracy/validity of the current scientific establishment’s explanations of the onset of ice ages. This doesn’t mean I don’t think they may be correct–rather, no scientific argument has been put forth (that I’ve seen) that fully explains it. So I’m asking you (since others here have not offered any assistance in this matter–though I would fully welcome input from this group) for your suggestions on what the most complete, compelling and defensible arguments (ideally including the math behind them!!!) are for the current prevailing theory(ies) on the onset of continental glaciation/ice ages. I believe arguments put forth thus far are too simplistic.
And while I may disagree with a fair portion of your views expressed here, at the end of the day we all benefit by ever more rigorous examination of our views and from being willing to listen to others. (True listening is the willingness to be altered by what you hear, after all.)
Thank you & have a good weekend,
DY
They had better remove the UHI factor from present day temperatures, keeping that upward UHI factor series separate, so you can apply it or not, or this BEST is just more junk science, simply trash.
Lady Life Grows says: April 2, 2011 at 11:22 am
Lady Life, there is a world of difference between screwing up and consciously setting out to deceive people.
Heathrow weather station has bright sunshine hours up over 220 hours per year. I suspect thats because of the cleaning up of the air.
Decade Sunshine Hours Total
1960s – 14555.7
1970s – 15118.6
1980s – 15264.4
1990s – 16801.9
2000s – 16776.8
http://www.metoffice.gov.uk/climate/uk/stationdata/heathrowdata.txt
2300 extra hours of sunshine from the 1960s to the 1990s/2000s.
That is a huge jump in energy from the sun.
Jones may be measuring the wrong thing again …
This really ticks me!!
Daytime summer temperatures are minimally affected by UHI, it is the winter nighttime temperatures where urban heat manifests itself the greatest. There is too much energy from the sun present on hot summer days. But in cold winter days and nights that urban heating really takes it toll on the anomalies.
Every rural station here in Oklahoma shows that same pattern. It makes it look like the Earth is warmer but it is mainly that we have warmer winter nights due to towns and cities. If you were to say that it doesn’t matter that January nights were 2 degrees warmer more recently then Oklahoma as a whole would show very little to no change since 1880 at all. Go pull up you nearby rural stations showing minimum and maximum plots seperately and you should see this, I think it is found at NCDC though I thought it had five letters.
We’ve been through all of this before.
What do we have, another sham going? Another brainless exercise in the misnomer called “CLIMATE SCIENCE”. Now it’s called the “BEST”. Do these people called “climatologists” not have brains?
The bottom line is this, until they seperate the seasons, the mid-spring to mid-fall and the mid-fall to mid-spring, and, keep seperate the maximum daytime records from the minimum nightime records, there is simply no hope on really seeing what the climate is doing. At least that is what the last sixteen months of digging deep into climate science has taught me.
Maybe they just need a very good scientific programmer? Maybe they just don’t know how to program that. Huh? There are still some around.
David Y says:
April 2, 2011 at 12:52 pm
….
I’m skeptical of the accuracy/validity of the current scientific establishment’s explanations of the onset of ice ages. This doesn’t mean I don’t think they may be correct–rather, no scientific argument has been put forth (that I’ve seen) that fully explains it.
….
I’m not a trained scientist David but I find Dr. Svensmark’s hypothesis for Gamma ray cloud seeding to be particularly interesting. I think the long period between ice ages can be simply explained by our solor system orbiting with the galaxy. As we pass through bands of high Gamma ray flux the cloud cover increases and cooling dominates. Moving out of the Gamma ray flux allows warming to occur. It’s simple explanation, I like it.
DirkH,
Thank you for posting that excellent graphic showing how GISS massages the past temperature record.
A similar urban heat island map of an entire country, e.g. the UK or US, with the positions of all weather stations marked on it, would be excellent publicity for the skeptic point of view.