Most of the country suffered the coldest September in 14 years, forecasters revealed.
In its monthly summary Met Eireann said the temperature never rose above 20 Celsius anywhere – the first such occurrence in more than 30 years.
Average monthly air temperatures were around half a degree below normal at some southern weather stations and it was the coolest September since 1994 almost everywhere. Forecasters said they were unable to predict the weather over the winter months but the Met Office in Britain claimed temperatures are likely to be above normal over much of Europe, although not as mild as last year.The summer washout seeped into the first half of September, with Dublin stations recording their usual monthly level of rainfall within the first six days.
This also brought the stations’ annual totals for 2008 above the amount normally recorded in a full year. Dublin Airport’s downpour of 43.5mm on the 5th was its highest level for September since the station opened in 1941, while torrential rain on September 9 and 10 caused widespread flooding, especially in the south and west.
I didn’t get to finish that last comment before it was posted (must have hit something accidentally). Anyway to conclude:
Although I accept the reality of UHI, I’m not convinced that it has had a significant influence on global trends over the last ~50 years. If UHI were a big factor there would be bigger discrepancies between satellite and surface trends. The satellite readings at the lower level of the atmosphere (900mb) are pretty consistent with the surface readings (or they were the last time I looked).
Put it this way – the UH effect is not a show stopper for AGW
It dropped to 32F here in the Catskill Mtns last night. So I’ll post to this blog one more of the numerous examples of “Local effects, in both time and space, have no real weight behind them” that span the globe and the past year.
2009 is going to be fun to watch.
AndyW,
Anthony posts what interests him. At the top of this page you will see:
“Watts Up With That?
Commentary on puzzling things in life, nature, science, technology, and recent news by Anthony Watts”.
Does that answer your question?
Mike Bryant
@John Finn:
How do you explain that if one excludes the urban monitoring stations, the warming trend decreases?
Chris
This is where the accuracy of surface data is critical. If people are taking from the raw data a global temperature increase of 0.7C (say) since the 1940s when the real figure should be 0.3C (say), then this represents the difference between evidence of greenhouse gases already having a noticeable effect, and evidence that global temperatures are still within the bounds of natural variation (and CO2 with negative/neutral rather than positive feedbacks).
It’s the 1940s temps which convince me we’re still within the bounds of natural variability. Up to the early 1940s temps were rising quite sharply. I see no reason why they wouldn’t have carried on rising. For example, solar activity (if it is a factor) was higher in the second half of the 20th century than was in the first. It was only a shift in the PDO that interrupted the upward trend. Extrapolate the 1910-1945 trend up to 1980, say, and you’ve got most of the warming we’ve seen to date. There’s certainly not much left for CO2.
Dee Norris (05:52:32) :
@John Finn:
How do you explain that if one excludes the urban monitoring stations, the warming trend decreases?
Does it? I’ve not seen that demonstrated on a global scale.
John Finn (05:39:44) :
” Put it this way – the UH effect is not a show stopper for AGW ”
NOTHING is a “showstopper” for AGW, right?
The show will go on, and on, and on, and on…
Jeff Alberts (20:58:59) :
” Not sure how that’s unseasonable, since the “normal” weather for the PNW in the fall is wet and cool… The warm and mild weather has been unseasonable.”
Warm and mild is not at all unseasonable in the Pacific Northwest (where I lived for 20+ years). It’s one of their better-kept secrets.
Summer weather is notoriously unreliable through the 4th of July, but once it arrives, it’s magnificent, and often will persist through September.
(Now that you know about their magnificent summers, DON’T tell anyone).
NWS said “unseasonably strong low pressure system,” but strong and deep Pacific low pressure systems are not at all unknown in October.
October 12, 1962 – the “Columbus Day Storm”…
still legendary in the Pacific Northwest, still holds many of the high-wind records
http://en.wikipedia.org/wiki/Columbus_Day_Storm
Speaking of legendary October windstorms, they’re well known in the UK as well
http://en.wikipedia.org/wiki/Great_Storm_of_1987
Looks like a hurricane-force storm is possible over the UK on Friday
http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/
@John Finn:
Why don’t you get a dump of all the surface stations, exclude the urban stations and plot the results.
John
It’s the 1940s temps which convince me we’re still within the bounds of natural variability. Up to the early 1940s temps were rising quite sharply. I see no reason why they wouldn’t have carried on rising. For example, solar activity (if it is a factor) was higher in the second half of the 20th century than was in the first. It was only a shift in the PDO that interrupted the upward trend. Extrapolate the 1910-1945 trend up to 1980, say, and you’ve got most of the warming we’ve seen to date. There’s certainly not much left for CO2.
The “consensus” reason why temps didn’t keep rising after the 1940s is of course the effects of increased aerosols in the atmosphere. But I agree with you that the coincidence of the cooling after the mid-1940s with the transition to -ve PDO is very striking. (And I find the aerosols explanation inconclusive, to say the least.)
Looking at http://data.giss.nasa.gov/gistemp/graphs/Fig.A4.lrg.gif
it seems the world’s oceans have warmed 0.3C from the peak in the early 1940s to the recent peak in the last few years. [Note, though, the early 40s peak may be in danger of downward revision because of the “bucket correction” issue…..]
So it’s the land data which appear to bring us into “unprecedented” territory with an increase of 0.7C since the 1940s peak.
And thus it’s the way the land data has been put together that I think is particularly important. It’s noteworthy that the US (which ought to provide some of the most accurate measurements across the width of a continent) only shows a temperature rise of ~0.2C from the 1940s to the 2000s
http://data.giss.nasa.gov/gistemp/graphs/Fig.D.lrg.gif
and even in northern Siberia which is supposed to be the forefront of global warming, the five most northerly stations with records going back to the 1940s spectacularly fail to correlate with the global graph:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=222202920005&data_set=1&num_neighbors=1
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=222214320004&data_set=1&num_neighbors=1
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=222206740006&data_set=1&num_neighbors=1
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=222216470000&data_set=1&num_neighbors=1
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=222208910006&data_set=1&num_neighbors=1
The same can be seen in the only 2 stations in Greenland going far enough back i.e. capital on west coast and largest town on east coast:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=431042500000&data_set=1&num_neighbors=1
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=431043600000&data_set=1&num_neighbors=1
Same goes for Iceland’s capital, and second largest urban area:
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=620040300000&data_set=1&num_neighbors=1
http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=620040630003&data_set=1&num_neighbors=1
None of this proves anything. But it does show that large swathes of the NH must have seen all the more warming in the last 70 years to make up for the lack of warming in the areas I’ve referred to, and I am yet to see a convincing explanation of how such consistent warmth circulating at high latitudes can have completely failed to have an impact on so many key locations.
Oh dear my attempt at emulating John’s use of italics for a quote has failed abysmally! To clarify, in my last post the first paragraph is a quote from John, and the second paragraph onwards (The “consensus” reason………) is my words.
Better go brush up on my html/tags/or whatever it is (i’m looking embarrassingly clueless here……)
John-X (06:40:20)
Confirmation of October storm
http://www.weatheraction.com/
Re: the PDO it will be interesting to see what the index is for September 2008. For August, it was -1.70 and there have only been two Augusts since records began with a larger negative figure: 1955 (-2.25) and 1920 (-2.21)
http://www.jisao.washington.edu/pdo/PDO.latest.
It seems to me that we may have been (and may still be) undergoing a triple whammy of cooling:
(1) -ve PDO pushing warm SST anomalies polewards where heat loss to space may be more effective;
(2) reduction in solar activity resulting in cooling of the upper atmosphere – I know it’s controversial, but what other explanation can there be for the exceptional coldness of the lower troposphere in recent months from middle levels upwards.
See e.g. http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps+003
and check boxes for all previous years (then click “redraw graph”) to see how every month has been colder than previous years, including 1999 and 2000 when there was a longer and deeper La Nina than the recent one.
This coldness could gradually propagate downwards via enhanced convection, precipation and cloudiness. (Like in Britain and Ireland over the summer?)
(3) increased hurricane/tropical storm activity cooling the tropical oceans and removing heat to higher latitudes (as well as to the anomalously cold higher altitudes)
Thus the “recovery” of global surface temperatures from La Nina over NH summer 08 may have been a red herring, as it may simply have represented a greater heat loss and thus a greater net cooling of the globe overall.
The real test will be to see just how cold this NH winter turns out to be. I’m not going so far as to predict it will be colder than expected, as I’m open minded! I’ve just got my suspicions about the widely-held assumption that global warming will come roaring back following the 2007/8 La Nina.
John Finn (05:39:44) : “If UHI were a big factor there would be bigger discrepancies between satellite and surface trends. The satellite readings at the lower level of the atmosphere (900mb) are pretty consistent with the surface readings (or they were the last time I looked).
Put it this way – the UH effect is not a show stopper for AGW”
I did a simple least-squares linear regression on the UAH global lower troposphere temperatures 12/1978-8/2008 (using MS Excel TREND function), and the average temperature increase was 0.129 deg C p.a.
Using the same function on Hadcrut3v global surface temperatures over the same period, the equivalent figure was 0.162 – 25% higher.
Non-trivial, I think.
I haven’t done the proper checks to make sure I haven’t made a mistake, but the data is public domain so please anyone here check that I have used the right data, and do the calcs for yourself.
Hadcrut3v global surface temps:
http://www.cru.uea.ac.uk/cru/data/temperature/hadcrut3gl.txt
UAH global LT temps:
http://vortex.nsstc.uah.edu/public/msu/t2lt/tltglhmam_5.2
(column 3 “GLOBAL”)
Chris
The “consensus” reason why temps didn’t keep rising after the 1940s is of course the effects of increased aerosols in the atmosphere. But I agree with you that the coincidence of the cooling after the mid-1940s with the transition to -ve PDO is very striking. (And I find the aerosols explanation inconclusive, to say the least.)
I think the aerosols explanation is nonsense and I suspect that a few AGW scientists do as well. Industrial aerosols (as opposed volcanic aerosols) are relatively short-lived ( a matter of days) so the majority of emissions remain close to the source location. Mann & Jones have produced a paper in which the uncertainty of the aerosol effect is discussed. They conclude that any aerosol effect is “regionally specific”. Similarly Levitus cites the local effect of aerosols as the cause for the lack of uniform warming in the oceans.
In a nutshell: Any cooling due to industrial aerosols should be most evident at the very locations that produced the aerosols, i.e. in the industrialised regions of the world. In the post-war period this was the US and Europe.
The following GISS dataset provides temperature data for different latitude bands (e.g. 0-24 deg, 24-44 deg , 44-64 deg, 64-90 deg)
http://data.giss.nasa.gov/gistemp/tabledata/ZonAnn.Ts+dSST.txt
Looking at trends for the period 1945-1975 there is a clear pattern. The greatest cooling, by far, is in the Arctic (64-90) regions. The industrialised mid-latitude regons do show cooling but not markedly so. The least cooling occurs in the tropics. This pattern of cooling is almost a mirror image of the post-1975 warming whereby the Arctic experienced the greatest warming and the tropics the least.
This suggests (to me at least) that cyclical process (ocean circulation) are responsible for the multi-decadal cool/warm phases and some other factor (possibly ghgs but more likely solar activity**) is responsible for the geneal upward trend.
** I say more likely solar (direct or indirect) because the upward trend began before there was any significant increase in ghgs above pre-industrial levels.
I did a simple least-squares linear regression on the UAH global lower troposphere temperatures 12/1978-8/2008 (using MS Excel TREND function), and the average temperature increase was 0.129 deg C p.a.
Using the same function on Hadcrut3v global surface temperatures over the same period, the equivalent figure was 0.162 – 25% higher.
You didn’t read what I wrote. You have compared the mid/lower trop satellite data with the surface data. Using only the satellite readings from 1000km (900mb) level (i.e. the lowest and therefore the closest readings to the surface) the trends are much closer – or so I believe. Unfortunatley readings for each level of the atmosphere are not readily available.
But I notice you used UAH data rather than RSS data – any reason for this?
John Finn (17:43:35) “You didn’t read what I wrote” : Maybe there’s a difference between reading and understanding… 🙂 [seriously, though, see 2nd para below]
“I notice you used UAH data rather than RSS data – any reason for this?” : I did the work on the figures after reading Douglass and Christy’s paper “Limits on CO2 Climate Forcing from Recent Temperature Data of Earth”
http://arxiv.org/ftp/arxiv/papers/0809/0809.0581.pdf
[Energy and Environment Aug 2008]
which said that they used UAH data because it was a bit better than RSS data, and gave reasons (best if you read the paper – see Appendix A).
“Unfortunatley readings for each level of the atmosphere are not readily available” : Quite. I used the best data I could find. I doubt it makes much difference to the argument if one takes data from further up the atmosphere, provided one doesn’t go above the level at which CO2 forcing takes place, if the ‘competition’ is essentially between the UHE (=UHI) and CO2 arguments/models. As I understand it, the CO2 signature should be that the troposphere warms up before and more than the surface, whereas the UHE signature would be the other way round.
Could the data soon to become available from NASA’s AIRS project (Atmospheric Infrared Sounder)
http://www-airs.jpl.nasa.gov/
possibly be of some use in this discussion??? If it shows how well CO2 is mixed at the various levels of the atmosphere, would that help in assessing how other things might vary between the different levels?? (NB. There’s an “if” in that sentence).
PS. My last post should have read “per decade” not “p.a.”.(!)
I posted a reply to John Finn and it disappeared (didn’t do that last time). If this appears OK, and the JF reply doesn’t, I’ll send the JF reply again but I didn’t have it all backed up (Grrrr).
John Finn (17:43:35) “You didn’t read what I wrote” : Maybe there’s a difference between reading and understanding… 🙂 [seriously, see 2nd para below]
“I notice you used UAH data rather than RSS data – any reason for this?” : I did the work on the figures after reading Douglass and Christy’s paper “Limits on CO2 Climate Forcing from Recent Temperature Data of Earth”
http://arxiv.org/ftp/arxiv/papers/0809/0809.0581.pdf
[Energy and Environment Aug 2008]
which said that they used UAH data because it was a bit better than RSS data, and gave reasons (best if you read the paper – see Appendix A).
“Unfortunatley readings for each level of the atmosphere are not readily available” : Quite. I used the best data I could find. I doubt it makes much difference to the argument if one takes data from further up the atmosphere, provided one doesn’t go above the level at which CO2 forcing takes place, if the ‘competition’ is essentially between the UHE (=UHI) and CO2 arguments/models. As I understand it, the CO2 signature should be that the troposphere warms up before and more than the surface, whereas the UHE signature would be the other way round.
Could the soon-to-be available data from NASA’s AIRS (Atmospheric Infrared Sounder) project possibly be useful in this discussion?? If (NB. if) it shows how well-mixed CO2 is at various levels of the atmosphere, it might give clues to how to treat other factors at different levels?????
PS. My 4-10 16:42:43 post said “p.a.” where it should have said “per decade”.(!)
Today on the 5th of October I woke with the first snowfall of the season, caused by a fast moving autumn storm.
This is one month to early for the first snow and although it is wet snow it is staying in the ground! This is unusual.
I live near sea level in Voss, west Norway not far from Bergen. I hate winters.
egrey
Like you, I had a bit of trouble posting last night (sat) but everything seems to have appeared this morning.
Your comments on the UAH and surface data are valid.
But my points (which I probably didn’t make clear) are that a) satellites and surface stations aren’t necessarily measuring the same thing; b) there is better agreement the nearer the satellite observations are to the surface; and c) considering the uncertainty with all methods (e.g. RSS v UAH) I don’t feel it’s possible state with any confidence that the surface record is significantly contaminated by UH.
On your point about the CO2/warming troposphere link. Quite right – but that’s a separate issue.
JF: “I don’t feel it’s possible state with any confidence that the surface record is significantly contaminated by UH.
On your point about the CO2/warming troposphere link. Quite right – but that’s a separate issue.”
It’s a bit like detectives in a whodunnit trying to put together motive, method and opportunity. We have to look for theory, evidence, and exclusion of alternatives.
Maybe it’s not possible yet to state with confidence that the surface record is seriously contaminated by UH, but the theory is clear, evidence is coming from more than one source – eg. weather station survey and surface vs troposphere temperatures – and importantly in the latter case CO2 can be excluded as an alternative because its signature is the opposite of what has been observed. I can also recommend this item from NASA, which does indicate that UH is real :
http://climate.jpl.nasa.gov/news/index.cfm?FuseAction=ShowNews&NewsID=24
Of increasing temperatures in S California it says “Most of the increase in heat days and length of heat waves … is due to a phenomenon called the “urban heat island effect.”
Heat island-induced heat waves are a growing concern for urban and suburban dwellers worldwide. According to the U.S. Environmental Protection Agency, studies around the world have shown that this effect makes urban areas from 2 to 10 degrees Fahrenheit (1 to 6 degrees Celsius) warmer than their surrounding rural areas. …this effect is steadily warming Southern California, though more modestly than some larger urban areas around the world.
Dramatic urbanization has resulted in an extreme makeover for Southern California, with more homes, lawns, shopping centers, traffic, freeways and agriculture, all absorbing and retaining solar radiation, making our megalopolis warmer…“
John Finn (17:50:33) :
The causes of the early 20th century warming are most probably due to heat transfer fluctuations through the North Atlantic and the North Pacific couple with increased radiative forcing from industrial emmisions. Models suggest that there was little or no impact from volcanic activity or solar activity during this time. Recent global temperatures from the late ’70’s on would have been similar, if not slightly less to the temperatures of the early 20th century, but they were much warmer. Only when you include the effects of increased CO2 into the models do they match recent observations.
Steve Berry (01:41:16) :
“John Finn. I bet my shares Mary Hinge doesn’t answer!”
Too bad Steve! Your shares are probably worthless now anyway!! 😉
Mary Hinge (07:34:15),
I take it this
pretty much captures your argument?
The way I read plots a and b in my link is that the models underestimate the warming around 1940 by ~0.5C and underestimate the change between ~1915 and ~1945 by around 0.7C.
Is “most probably” an IPCC definition?