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#802448 - 04/12/2009 07:46 Temperature trends - Archive
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 2755
Loc: Buderim
Latest Uah is out, with a value of 0.5. A quick scan through previous values shows this is the hottest November in the last 30 years by 0.1 degrees.





Earlier this month I posted a crude statistical model which attempted to predict temperatures this summer based on a Co2 warming trend of 0.18 degrees/month, and a typical El Nino warming curve. The prediction for November was 0.41 degrees, and most of the warming due to the El Nino is expected between January and June next year.

Full set of predicted values is:

Nov....0.41
Dec....0.45
Jan....0.62
Feb....0.56
Mar....0.46
Apr....0.51
May....0.44
Jun....0.44


Edited by Seabreeze (23/10/2012 20:28)

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#802471 - 04/12/2009 10:13 Re: Temperature trends [Re: Mike Hauber]
AndrewMurrell Offline
Cloud Gazer

Registered: 24/11/2009
Posts: 26
Loc: NSW Umina
To me it looks like the graph shows at best a 0.3 degree rise in average temp in 30 years.
Hardly the doom and gloom associated with AGW. It would be interesting to see what the graph would look like if we had 100 years of Satellite measurements. I would assume that 0.3 degree change would be nothing but the norm. Afterall one of the hottest decades in the 20th Century was the 30's, well outside the real infulence of AGW.
Andrew

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#802508 - 04/12/2009 16:37 Re: Temperature trends [Re: AndrewMurrell]
Severely Tall Offline
Weather Freak

Registered: 16/11/2006
Posts: 751
Loc: Melbourne, Victoria
Clearly you have missed something Andrew, it starts subzero, hence is above what you have noticed (for a 30 year trend) We dont have 100 years of satellite measurements, nor will we at any stage, so once again all that can be done is speculate based on hearsay and secondary sources...without any evidence which prooves the 30's were 'one of the hottest decades' being even comparible on mean temperatures to the present period.
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#802512 - 04/12/2009 17:25 Re: Temperature trends [Re: Severely Tall]
AndrewMurrell Offline
Cloud Gazer

Registered: 24/11/2009
Posts: 26
Loc: NSW Umina
No don't think I missed anything. The year of 79 was exactly average, remember this is a years average temperature(half the year above and half below). 79-83 was Solar Minumum so that covers the slight drop in temp in 82-86, back to average till 95 then the effect of the El Nino warming which fell back and then a slight rise of 0.3 degree. Am I missing something??? Hearsay and speculation devestated the central states of the USA, remember the dust bowl.(probably not).

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#802516 - 04/12/2009 17:40 Re: Temperature trends [Re: AndrewMurrell]
Arnost Offline
Weatherzone Addict

Registered: 10/02/2007
Posts: 3908
Andrew, yes you are missing something...

The years 81-82 were subject to "El Chichon cooling". The dip is not as apparent as the "Mt Pinatubo cooling" as it was masked by the Nino of the Century (up to that time)... Without El Chichon, the temps would have been at least up to the peak of those over the last 7 years or so.

_________________________
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And this of course applies to scientific principles. Never compromise these. Never! [Follow the science and you will be shown correct in the end...]

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#802597 - 05/12/2009 07:20 Re: Temperature trends [Re: AndrewMurrell]
Mike Hauber Offline
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Registered: 13/07/2007
Posts: 2755
Loc: Buderim
Originally Posted By: AndrewMurrell
To me it looks like the graph shows at best a 0.3 degree rise in average temp in 30 years.
Hardly the doom and gloom associated with AGW.


A 0.1 degree/decade trend over 100 years is a further 1 degree temperature rise. However the rise could easily be higher because of these reasons:
- the temperature inrease is predicted to accelerate significantly over the next 100 years. The current rate of warming expected by models is roughly 0.2 degrees/decade, and it would have been lower for the start of the last 30 years.
- a linear regressions shows a warming rate between 1980 and 2009 of 0.126 deg/decade.
- Uah shows roughly 20% less warming than CRU, GISS or RSS since 1980. It shows about the same rate since 1992. In 1992 there was a significant change in satellite instrumentation, and a step change between Uah and RSS. So quite reasonable (but not necessarily certain) that Uah's lower warming trend is an error.

Then consider natural variations. If we could be confident that natural variations since 1980 have been warming or neutral we could try and use the recent trend to put an upper limit on future warming. In this period we have had one volcano early in the period contributing early cooling, so making the overall trend warmer. Another volcano near the middle, so having little effect on the overall trend. Also AMO would be in its peak warm phase sometime close to the end of this period.

In contrast PDO was warm for the first 20 years of this period, and has been just barely negative since 1999. Solar has been on a downward trend since 1980. And then there could be other factors we haven't year considered. I don't know which way natural variation would go for the 1980-2009 period, but I doubt anyone has a convincing reason that it must have contributed warming not cooling, so we can't guarantee that the recent warming is an upper limit on what we can expect in the future.

Originally Posted By: AndrewMurrell

It would be interesting to see what the graph would look like if we had 100 years of Satellite measurements. I would assume that 0.3 degree change would be nothing but the norm. Afterall one of the hottest decades in the 20th Century was the 30's, well outside the real infulence of AGW.
Andrew


Well GISS would be the best we've got for temps in the 30s, unless we want to rely on what an imaginary satellite sensor might have shown...


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#802600 - 05/12/2009 08:04 Re: Temperature trends [Re: Mike Hauber]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Funny how 2 graphs look so different in your last 2 posts Mike...One gets an entirely different view looking at it spread out from 1880 onwards, then narrowed down to from 1979 onwards. Just a comment on how one can get an opposite looking effect by changing the graph Z and Y axis length and depth.
Not having a go, just amazing what can be done with graphs to alter the perspective. From 1700 onwards or 1400 onwards would look very different also.
And using different systems of temp measurement would also look very different, when stretched or squashed or lengthened or narrowed or whatever.
One can also plot someting else together with it and change those dimensions to do whatever one likes also. Just interesting, that is all.

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#802922 - 07/12/2009 00:08 Re: Temperature trends [Re: bd bucketingdown]
SBT Offline
Meteorological Motor Mouth

Registered: 07/02/2007
Posts: 14156
Loc: Townsville Dry Tropics
.1C rise huh. Might have to get another fan in about 75 years or so but the again maybe not.
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#803085 - 07/12/2009 23:11 Re: Temperature trends [Re: SBT]
BOM99 Offline
Weatherzone Addict

Registered: 23/08/2004
Posts: 4645
Loc: Australia
I still see one big problem with assuming anything about temp trends prior to last century that is that there are no reliable temperature observations anywhere in the world before 1900. That means that all asumptions about the climate prior to that point are in reality very sketchy and inaccurate. The fact remains that during the period of accurate measurments the temperature trend is up. Not only that the temperature trend in the period of most accurate measurments is very strongly UP. In fact the temp peak of 1998 was not the hottest and corectly 2005 was the hottest as shown by Mike's graph above due to missing data in 1998. This year will be the hottest in many places, Just take a look at the satelite data nearly all levels are at record highs now.

Anyway my point is that in reality we know very little about past climates except for the last major ice age so there is little substance in refering to the past. Its like me saying "oh my granddaa said he nearly melted out on the back porch when he was a kid" It just means nothing. Just the extremes of the hydrological cycle are screaming the increased heating. Rainfall is more and more erratic. When its dry its really hot and dry and when water is involved evaporation is strong and you get crazy floods like at Coffs this year while the inland just gets drier.

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#803087 - 07/12/2009 23:23 Re: Temperature trends [Re: SBT]
marakai Offline
Weatherzone Addict

Registered: 05/01/2006
Posts: 1746
Loc: Maryfarms NQ
G'day all.

I'm not poking or trying to stir things up, but not being very up to date on the latest technical variables on the way to measure the temperature I decided to go back to basic's and check out the actual temperature as recorded.

I did this because upon reading the latest temperature trends for Aus on Bom I noticed that they are given based on the thirty year trend and being what I am I decided to look a little more and checked on some history.

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13


Have a look at them they are all above the current high temps and some by a long shot.

why does BOM only base the current temps over a thirty year period and then bleat about record temps (based only on a thirty year mean?) when it isnt so?

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#803096 - 08/12/2009 00:24 Re: Temperature trends [Re: marakai]
aerology Offline
Weather Freak

Registered: 05/11/2009
Posts: 92
There are a lot of things that make no sense, till you look at the old record books, there were pages for the daily hourly reading one month per page, pages for daily Highs, low and averages for each month with a monthly average for each in the last line, From these were drawn the monthly normals, and departures from normals.

Toward the end of the book, pages with columns for the recording, of these monthly values for each year, thirty lines on a page, thirty years in a book, when figuring the long term averages, they used to just pull out the older books, and jot down these figures from each book.

I have made copies of all of the old original records they have in this town "Concordia, Kansas USA" from early 1885 raw direct from the books. There are initials and amounts of side bets made per month, by the data collectors, as to who could guess the ave high's lows and the average temp the closest. It would be my guess that this was not just a local idea.

They would be much better off with using a 60 year average, as it would reflect at least one 55.8 year pattern of 3 Lunar declination swings of the 18.6 year Mn pattern and give some smoothing, rather than using 30 years that produces 1.6 parts of the 18.6 Mn that then weights some .6 part of the signal twice against one whole.

130.2 years would give 7 complete cycles, to give an even better idea of the consistency across time series and still almost/fit inside the limits of the total available, data collection window.

Old habits die hard, even across multiple generations, of retired workers.

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#803101 - 08/12/2009 01:20 Re: Temperature trends [Re: aerology]
marakai Offline
Weatherzone Addict

Registered: 05/01/2006
Posts: 1746
Loc: Maryfarms NQ
Even without the extended averages that you talk of Aerology my point is that the observed temps over the long range dismiss the supposed recent hotter than average when taken over long term observations.

I would like to know why they are based on a thirty year average rather than overall since recording began. After all these are what we see in the headlines in print and on telly.

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#803126 - 08/12/2009 06:45 Re: Temperature trends [Re: marakai]
Ben Sandilands Offline
Weatherzone Addict

Registered: 07/09/2006
Posts: 1252
Loc: Southern highlands NSW
There is no doubt in my mind of the influence of direct observation on the personal perception of temperature changes.

And this is regardless of the causes.

As the keeper of family archives, backed up by many conversations with relatives, and access to their photo albums, quite exceptional warming has occurred since the latter stages of the 19th century in Iowa and in New South Wales, in Otago, in Washington state, and even in what was in living memory 'alpine' parts of Papua.

In Iowa for example, the family photos and press clippings and other diary material do show or record dusty spells and warm spells too, like snow free ground in November early in the last century, when such an occurrence was abnormal rather than normal as it is today.

But to be fair, both situations may be 'normal', and the changes to atmospheric chemistry and the rise of fossil fuel consumption, purely coincidental at multiple points and totally unrelated to the changes in the records. If it makes people feel more comfortable to believe there is no relationship, so be it.

I find it difficult to reconcile however the deglaciation of temperate icefields across widely dispersed locations with claims that the world hasn't become 'warmer'.

I find it very hard to reconcile the disappearance of heavy snowy winters from the Blue Mountains and southern highlands and the Monaro in my lifetime, and in the records of previous generations, with a world that has not really become warmer.

I refer to times when snowy winter followed snowy winter, or what passed for a 'snowy' winter in Australian terms, but would have been seen as trivial in the contemporary northern world.

The critical element in climate and atmospheric research is to provide detail or 'granularity' to the natural variabilities and those that can be linked to the sudden and massive release of fossil carbon and synthetic halons never before present in the atmosphere.

That research is now trapped between two extremes in the popular debate, which seem to share only one thing in common, which is a conviction that the science is settled, and there is no further need to research anything which might upset their respective preconceptions.




Edited by Ben Sandilands (08/12/2009 06:47)

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#803143 - 08/12/2009 08:11 Re: Temperature trends [Re: marakai]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 2755
Loc: Buderim
Originally Posted By: marakai
G'day all.

I'm not poking or trying to stir things up, but not being very up to date on the latest technical variables on the way to measure the temperature I decided to go back to basic's and check out the actual temperature as recorded.

I did this because upon reading the latest temperature trends for Aus on Bom I noticed that they are given based on the thirty year trend and being what I am I decided to look a little more and checked on some history.

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13

http://www.bom.gov.au/jsp/ncc/cdio/weath...e=40&p_month=13


Have a look at them they are all above the current high temps and some by a long shot.

why does BOM only base the current temps over a thirty year period and then bleat about record temps (based only on a thirty year mean?) when it isnt so?



With so many stations available, it is not surprising there are a few with charts like that. I note they are for extreme values, which being a very small set of values is more suspectable to random fluctuations. In contrast, picking the first one of your links and checking the annual average temperature shows a definite upward trend.

Link: Sydney Observatory Hill

Anyone interested in creating their own charts start here: link

And using a 30 year aseline has no effect on which temperature is a record temperature. It has no effect on the trend. It only effects where the entire temperature series sits compared to the 'zero' line.

Edit:

Skeptical Science have an interesting article on proxy reconstructions. The post is focused on issues around the medieval warm period, which i am not overly interested in. But one thing I note is that there are many different proxies for temperature, not just tree rings, and most of these proxies show good agreement with the modern temperature record since 1900. A notable exception being a decline in temperatures showed by some (many?) tree ring proxies since 1960.

There is a lot more evidence for a warming trend throughout the 20th century beyond what the instrument record, as we are seeing many effects on the natural world consistent with such a temperature rise.


Edited by Mike Hauber (08/12/2009 08:19)

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#803244 - 08/12/2009 13:56 Re: Temperature trends [Re: Mike Hauber]
Anemoi Offline
Cloud Gazer

Registered: 09/08/2009
Posts: 45
Loc: sub-tropics

Seems to me that it is blindingly obvious that the number of hot and very hot days imn Australia has increased over time, and the number of cold and very cold days has reduced as well.
Another metric that is available to everyone through the BOM

http://reg.bom.gov.au/cgi-bin/climate/change/extremes/timeseries.cgi

Cut it anyway you want, there has been a trend ongoing for decades of increased temperatures.
With numerous biological signals (flowering times, breeding times for animals etc) that further support a climatic shift to a hotter world.
The evidence for CO2 induced climate change seems pretty irrefutable on the basis of current scientific knowledge and recorded observations.

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#803269 - 08/12/2009 14:46 Re: Temperature trends [Re: Anemoi]
BOM99 Offline
Weatherzone Addict

Registered: 23/08/2004
Posts: 4645
Loc: Australia
Originally Posted By: Anemoi
Seems to me that it is blindingly obvious that the number of hot and very hot days imn Australia has increased over time, and the number of cold and very cold days has reduced as well.


I could not agree with you more, could not be any more obvious than it is.


Edited by Black Nor'easter (08/12/2009 14:53)
Edit Reason: provocative and inflamatory comments removed

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#803271 - 08/12/2009 14:52 Re: Temperature trends [Re: BOM99]
Long Road Home Offline
Meteorological Motor Mouth

Registered: 08/10/2007
Posts: 8329
Loc: Northern Beaches Syd
Yeah increased over the last 40 years, which is hardly a microscopic speck in the timeline of the earth.


Edited by Black Nor'easter (08/12/2009 14:54)
Edit Reason: unecessary comments removed

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#803474 - 09/12/2009 01:53 Re: Temperature trends [Re: Long Road Home]
Arnost Offline
Weatherzone Addict

Registered: 10/02/2007
Posts: 3908
Quote:
He who controls the present controls the past,
He who controls the past controls the future...

I think that the Met Office has updated the global temperature record.



The above is the new global land stations (CRUTEM3) plot from 1850. Looks like the mid 20th Century hump has all but disappeared. From the climategate emails, there is one that discusses decreasing the sea-surface hump in the 40's by 0.15C (linky). So I predict the Land and Sea temps will shortly be missing this hump as well - perfectly correlating with CO2 (sigh). linky
_________________________
“No. Not even in the face of Armageddon. Never compromise” ...

And this of course applies to scientific principles. Never compromise these. Never! [Follow the science and you will be shown correct in the end...]

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#803475 - 09/12/2009 02:12 Re: Temperature trends [Re: Arnost]
Arnost Offline
Weatherzone Addict

Registered: 10/02/2007
Posts: 3908
_________________________
“No. Not even in the face of Armageddon. Never compromise” ...

And this of course applies to scientific principles. Never compromise these. Never! [Follow the science and you will be shown correct in the end...]

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#803476 - 09/12/2009 02:22 Re: Temperature trends [Re: Arnost]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Obviously after that graph and this darwin, etc gear nothing at all can be believed from past temperature records, as they are just about all doctored up and altered so much in favour of AGW that they all read like fiction novels. What a joke, it would be funny if it were not so serious!!!
http://wattsupwiththat.com/2009/12/08/the-smoking-gun-at-darwin-zero/#more-13818

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