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jethro

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Posted
  • Location: Near Newton Abbot or east Dartmoor, Devon
  • Location: Near Newton Abbot or east Dartmoor, Devon

Oh - I ddin't realise that. I thought it was peer-reviewed etc etc. Still, paid me money ... it's not actually a great paper, with the most obvious 'problems' that assertions which are built on later are unreferenced. These may well be entirely accurate, and, indeed obvious - but for a lay-person like me, I'd rather see why it is the case. So didn't get past page three, unfortunately.

Well, then that would be theft then, wouldn't it?

It's on a sceptic site (and it might be the pre publication version) and sceptic sites don't handle stolen goods?

Isn't that a little closed minded Dev?

Only if you think my mind should be so open it can fall out. But, hey, come back in a year or two and ask me again when Roy Clark has got his Nobel prize :)

Jethro, you and I have followed these debates for some time, me probably for longer. I'd be a wealthy man if I had a pound for every time some has come along and announced they'd rewritten a crucial part of the atmosphere science and physics that describes the greenhouse effect.

So, yes, I think it's highly unlikely that Roy Clark is right. However if he is right I wont deny it.

Edited by Devonian
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Posted
  • Location: Near Newton Abbot or east Dartmoor, Devon
  • Location: Near Newton Abbot or east Dartmoor, Devon

Wot?

Perhaps a bit oblique for early in the morning :) Think CRU emails and irony...

Link to the paper - as I say it might not be the publication version.

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Posted
  • Location: Edinburgh
  • Location: Edinburgh

Y.S., I find this comment of yours rather ironic:

"Try not to dismiss everything that anybody posts because its not to your view. :yahoo:"

You do exactly that repeatedly, as well as insulting climate scientists and myself on the way, as you have done in that last post and several previous ones this week. I have provided critiques (some rather detailed and time-consuming) of some of the evidence you have provided, and I am usually met with a barrage of insults and put-downs, rather than reasoned scientific debate (you say you're a scientist - do you act the same way around your colleagues?).

For an assessment of Craig Loehle's E&E publication, Rob Honeycutt's review is worth a look.

http://www.skepticalscience.com/Kung-fu-Climate.html

The key point about Loehle's work, Y.S., is that the series ended in 1935, and that the series were unweighted in any way. Loehle/McCulloch have since published major corrections:

http://www.econ.ohio-state.edu/jhm/AGW/Loehle/SupplementaryInfo.pdf

which places the MWP similar to the 1930s. We're now ~0.5C above that level.

Loehle's corrected study on top of Mann's study:

http://farm3.static.flickr.com/2666/3914214320_261cba1cf2_o.png

Corrections came about partly as a result of this article at RealClimate:

http://www.realclimate.org/index.php/archives/2007/12/past-reconstructions/

Basically Loehle's reconstruction ends up not too dissimilar to many major reconstructions.

Spencer's work has been repeatedly criticised both in the literature and elsewhere. His cloud hypothesis does not stand on strong ground, as you would be aware if you'd read some of the papers I've previously linked to.

http://www.realclimate.org/index.php/archives/2008/05/how-to-cook-a-graph-in-three-easy-lessons/

A rather different take on Spencer's graphs...

I would suggest that you (Y.S.) open your mind to the possibility that the great majority of climate scientists might be right, that cycles do not explain global warming. I trust that your faith in the PDO has prevented you from deriving a temperature reconstruction for the North Pacific, which shows a warming trend very similar to the global warming trend. You repeatedly confuse a spatial pattern of change with absolute temperature change. Of course salmon in California respond to the PDO as they are next to one of the biggest signals of this spatial pattern across the North Pacific - the author of that presentation was concerned with how the frequency of PDO oscillations (if you can call a pattern that is one-and-a-half cycles old a true oscillation) changed in recent years, perhaps due to global warming! What would the case be if you were on an island in the central North Pacific?

And have you done that temperature trend graph for UAH yet? Try 1980-2000, then project forwards to 2010. Do the same for any other global temperature proxy, and see what you find. Has global warming stopped? No. Has global warming even slowed down? Nope. Is UAH significantly different to other temperature measures? Nope again. You can verify that yourself, it's not just an assertion from me.

woodfortrees.org is useful for this:

UAH: http://www.woodfortrees.org/plot/uah/from:1980/to:2011/every:1/plot/uah/from:1979/to:2000/every:1/trend

GISTEMP: http://www.woodfortrees.org/plot/gistemp/from:1980/to:2011/every:1/plot/gistemp/from:1979/to:2000/every:1/trend

Despite what some say on here I'm quite willing to look at alternative evidence, but so far none presented stands up to scrutiny.

sss

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

Basically Loehle's reconstruction ends up not too dissimilar to many major reconstructions.

Spencer's work has been repeatedly criticised both in the literature and elsewhere. His cloud hypothesis does not stand on strong ground, as you would be aware if you'd read some of the papers I've previously linked to.

Despite what some say on here I'm quite willing to look at alternative evidence, but so far none presented stands up to scrutiny.

sss

SSS

Perhaps you should take the time to read back over some of your recent postings !!

I've got the 2008 updated Loehle's graph right in front of me:

Posted Image

Even allowing for a 0.5 degree increase, you can clearly see the medieval warm period and also LIA ........ CAN YOU NOT ?

His conclusions were not affected at all by the corrections he made:

"A climatic reconstruction published in E&E (Loehle, 2007) is corrected for various errors and data issues, with little change in the results. Standard errors and 95% CI are added. The MWP was significantly warmer than the bimillennial average durig most of the period 820-1040 AD. The LIA was significantly cooler that the everage during most of 1440-1740 AD. The warmest tridecade of the MWP was warmer than the most recent tridecade, but not significantly so".

Here is his map of proxy locations (does not use a predominance of tree-ring proxies from the USA like a certain Dr Mann !!):

Posted Image

Given that we know for fact that the Northern hemisphere experienced a temperature profile that looked like the above and there are numerous non-tree ring proxy data reconstructions (see previous posts and in particular the reference to the Indo-pacific warm pool paper) this also fits in with this picture .....

...... or we can believe that these events were not global ...... based on the heavily flawed, de-bunked and downright ridiculous hockey stick graph of Dr Mann's (I have not insulted him, only his work in this area), for which the IPCC dropped the graph like a hot potato from its fourth assessment report !!!

Spencer's review (its a review), is based on multiple peer reviewed papers and is a different possibility. You seem unable or willing to grasp this concept. His area of relevant expertise is in modelling to which he is heavily critical of the IPCC ..... as are may others including a certain Dr Robert Linzden.

Dr Roy Spencers work on cloud feedbacks are also relevant and new.

You seem to want to put greater weight on anybody who upholds the status quo view and heaviy critisise anything and everything else.

I will state again ... Co2 is a greenhouse gas and I am sure has contributed to the warming we have seen, but when you take a stand back and look at the big picture, the amount of warming down to just CO2 emissions seems implausible. Some of it yes, but natural cycles could also be contributing greatly.

Your last statement is a laugh ...... you mean that the alternative science does not stand up to your scrutiny ........... I couldn't care less. You believe what you will.

Y.S

Edited by Yorkshiresnows
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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

I'm a bit confused?

How long did the other climate variations last and how long is this one meant to last?

Seems to me that past events show the hallmark of short term climate conflagrations whereas this one is a long term single driver warming. With the lifetime of CO2 being measured into the thousands of years, and the 'carbon cycle' only starting to add it's contributions, the 'plot on the graph viewed in 3010 will show a marked difference between the oft quoted 'short' period warmings and our long term climate shift.

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

I'm a bit confused?

How long did the other climate variations last and how long is this one meant to last?

Seems to me that past events show the hallmark of short term climate conflagrations whereas this one is a long term single driver warming. With the lifetime of CO2 being measured into the thousands of years, and the 'carbon cycle' only starting to add it's contributions, the 'plot on the graph viewed in 3010 will show a marked difference between the oft quoted 'short' period warmings and our long term climate shift.

Hi G.W

How they exactly came about and why they lasted and waned as they did is open to question, but clearly CO2 was not a factor.

Cycles / PDO / AMO Ocean currents / Gulf stream and of course solar activity (see Landsheidt).

If this was so back then, then its is possible that cycles hold a part of the answer to now (PDO test coming up and of course the possibility of a Maunder type solar minimum).

The predictions are currently for a colder 2011 (and cooling second half of 2010 ... though as Kold has previously posted, the real dive will likely be towards the latter part of this and into next year due to the warm Atlantic).

Time will as ever tell.

Y.S

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

I don't know whether I can fully agree about the lack of CO2 in the 'cycles' as the carbon cycle is as linked to all the other cycles as any one of them.

We know that past warmings have altered the carbon cycle to support the warming and the reverse for past coolings.

I'm quite sold on the research pointing to thedestruction of meso-America/European plague being linked to the L.I.A. by it's 'soaking up' of CO2 as the Forrest reclaimed past cities/agricultural lands.

If we over-ride other 'natural cycles' by flooding the atmosphere with GHG's then we experience a different type of warming (as we saw in the early Tertiary when we last saw GHG levels rise well above our current levels). We all know what happened in that period of warming including over 200ft of sea level rise.

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Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

Do you think the carbon cycle governs all climate change?

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

For the fact that our blanket of GHG's makes our planet inhabitable I would say that has to be linked to all of our past climate shifts even if the initial driver is flood basalt outpourings.Asteroid strike, major oregenic mountain building phases, major volcanic eruptions, orbital forcings etc.

The 'Carbon cycle' ,to me, governs the long term climate where as some of the above are merely 'blips' in time that would not be recognisable in the paleo records had they not 'forced' the carbon cycle to respond and the climate along with it.

You might say some of the above events equate to 'weather' whereas the carbon cycle equates to 'climate'?

To ask a question of a question do you feel GHG's play no part in climate shifts?

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Posted
  • Location: Cheddar Valley, 20mtrs asl
  • Weather Preferences: Snow and lots of it or warm and sunny, no mediocre dross
  • Location: Cheddar Valley, 20mtrs asl

I think they play a part but I don't think they govern or drive climate.

Personally, I think the oceans hold the answer and until we have a much better understanding of what drives the different currents, both upper ocean and bottom, we won't really know what happens and why.

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Posted
  • Location: Edinburgh
  • Location: Edinburgh

Y.S, you have a certain obsession with Mann and North American tree rings. Fortunately Mann (as published, with 1200+ datasets worldwide) does not. Most published reconstructions have the LIA and MWP to some extent, but they all have the 20th Century warming as pronounced, rapid and taking temperatures above those seen in the past. But it is stunningly naive to think that just because we had variation in the past (which is accountable within our best models of climate forcing), that somehow our large forcing of CO2 would not have the large effect that is predicted by basic physics, with amplification that is both predicted and observed, just because climate has changed before. I'm not going to waste my time with your ramblings any more, as you're clearly incapable of a civil debate with someone who dares suggest that your sources of information have significant deficiencies. Spencer, Landscheidt, Taylor and MacIntyre have so many well-documented failings in their research ("research" in the case of Taylor) - I pointed out some of these deficiencies with sources and data to support my points, yet you seem unable to make a sensible assessment of those sources without resorting to shouting. Shouting isn't a very good way to encourage a debating opponent to consider your words worth listening to.

Hi Jethro and G-W, the carbon cycle question is an interesting one. So far as I see it, there are a few factors as well as carbon that influence climate on the very long (geological) scale - such as continental configuration, volcanicity and solar brightness. Ultimately it seems reasonable that the influences of each factor on the carbon cycle then drive the climate of the planet. This seems to have successfully explained the major climatic shifts of the past, the generally higher CO2 concentrations of the past (countered by a fainter Sun), snowball/hothouse Earth conditions etc. In many cases the processes of release and long-term storage of carbon are slow, but we can see examples of fairly rapid release at the end of glacial cycles, or associated with the PETM. If current understanding of the carbon cycle is right, we should be able to explain the long-term and short-term changes using similar processes? So far as I can see, we can, and the implication for our currenrt warming is that we are very rapidly releasing a large amount of carbon into the atmosphere, and this will take a long time to be sequestered back into the geological carbon cycle. Whenever large amounts of carbon have been released (whether by a temperature feedback or by an independent process), significant warming has also occurred, such as we are observing now. I haven't seen good evidence to suggest that the carbon cycle should be anything other than the dominant thermostat on the Earth, after the raw brightness (not variability) of the Sun over geological time.

sss

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Posted
  • Location: Swallownest, Sheffield 83m ASL
  • Location: Swallownest, Sheffield 83m ASL

In many cases the processes of release and long-term storage of carbon are slow, but we can see examples of fairly rapid release at the end of glacial cycles, or associated with the PETM. If current understanding of the carbon cycle is right, we should be able to explain the long-term and short-term changes using similar processes? So far as I can see, we can, and the implication for our currenrt warming is that we are very rapidly releasing a large amount of carbon into the atmosphere, and this will take a long time to be sequestered back into the geological carbon cycle.

Forgive me for asking this and I apologise if my grey cells are on the way out but are we not at or near the end of a glacial cycle? Wouldn't this cause the fairly rapid release of CO2 as we are observing? I think we are a long way short of seeing the whole picture here because so many people use the same arguments for different things. Is there any wonder why Joe Public show a general amount of apathy on this subject?

How sure is anyone that it is man made and not natural when natural can cause exactly the same observations? Also, we are in a period of anomalous cold given the "normal" temperature of this planet if proxies are really that accurate......

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

Grey Cells P.P.

Differing carbon from differing sources is easily traced and the carbon from coal and oil are no exceptions. Seeing as the bulk of the icrease is of these two types I think it safe to assume that we still await the bulk of the CO2 feedbacks 'CO2' that the current warming will drive (which will have their own unique fingerprints too).:)

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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

Y.S, you have a certain obsession with Mann and North American tree rings. Fortunately Mann (as published, with 1200+ datasets worldwide) does not. Most published reconstructions have the LIA and MWP to some extent, but they all have the 20th Century warming as pronounced, rapid and taking temperatures above those seen in the past. But it is stunningly naive to think that just because we had variation in the past (which is accountable within our best models of climate forcing), that somehow our large forcing of CO2 would not have the large effect that is predicted by basic physics, with amplification that is both predicted and observed, just because climate has changed before. I'm not going to waste my time with your ramblings any more, as you're clearly incapable of a civil debate with someone who dares suggest that your sources of information have significant deficiencies. Spencer, Landscheidt, Taylor and MacIntyre have so many well-documented failings in their research ("research" in the case of Taylor) - I pointed out some of these deficiencies with sources and data to support my points, yet you seem unable to make a sensible assessment of those sources without resorting to shouting. Shouting isn't a very good way to encourage a debating opponent to consider your words worth listening to.

sss

Crikey !!

Anyway, ...... obviously I'm not the only one with silly views .....

Here's somebody else that seems pretty keen on cycles and the PDO' potential role.

http://www.accuweath...bal-warming.asp

I just pointed out a huge flaw in earlier post .... but you seem happy enough to dismiss that. If cO2 does not have the forcing power you suggest (and there is plenty of discourse within the IPCC on exactly how it does it) ....... then your argument will be wrong. The truth is we just do not know for sure ....... as you well know.

You keep coming across as knowing more than anybody else ...... which is just complete cobblers in my view.

Mann's hockey stick papers include tree-ring proxy data, and that includes the 2008 version. He can only get a hockey stick by the inclusion of the fabled Tilander lake mud series or inclusion of tree-ring proxies and used these to bolster a false argument i.e from 2008, if you take away the tree-ring proxy data I can still get a hockey stick (but I have to include the false Tilandjer Lake sediment series), and if I remove the Lake sediment series I also get a hockey stick (relying on the critisised tree-ring proxy series). Take away both ..... I do not see a hockey stick !!!!

Hey, come off it, you spent god knows how many posts defending that silly graph and now you state that most reconstructions have the LIA and medieval warm period so what is the fuss all about ........ No, that was not what Mann was attempting to get away with. His graphs 1998/1999 showed no LIA and no Medieval warm period ...... that was the whole point. The IPCC shoved that graph all over the third assessment report to illustrate the view that the globe had not seen such warming before and that globally the past 2000 years was pretty static ....... the shaft of the Hockey stick. It was therefore all down to Co2 and man.

http://climateaudit.org/

http://climateaudit....9/12/nas-mm.pdf

Here's why the obsession with north American tree-ring proxies (not my obsession ... just appears throughout the key papers !!)

http://climateaudit....yre-ee-2005.pdf

Here's the Wegman report ...... the one you think is flawed !!

http://www.uoguelph....egmanReport.pdf

Background on the participants .... and questions asked and answered.

http://www.uoguelph....pakResponse.pdf

What we can clearly see today is that this was not so, and no I disagree with you on how the reconstructions all show the current warming as being greater than the medieval period ..... that is just not so. Nobody can state for certain as today we can measure year to year variations e.g. 1998 warmest in current era, 1999 was not. Past temperature reconstructions that far back only look at an average for 20-30 year intervals .... sometimes more. As such the medieval warm period could have had several years warmer than 1998 .... or perhaps not. The truth is we will never know unless warming continues over the next few years.

Y.S

Edited by Yorkshiresnows
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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

I take it, Y.S., that when PDO-ve proves to be milded out by 'other drivers' you'll start to accept that we have had a major influence on the workings of our climate and that these small shifts are, like the melting of the Arctic ice mass in the 50's ,just the start of the full impact of the changes we have driven?

I refer you again to the paper Mark Serreze (head of NSIDC) was kind enough to point us to in his E-Mail to me today;

http://www3.interscience.wiley.com/cgi-bin/fulltext/122665675/PDFSTART?CRETRY=1&SRETRY=0

and ask you where you have issues with these observations.

We are in a changing world and the general direction of that change is undeniable (surely?) merely the scale of those impacts is up for debate. How you can think that to change one part of a closed system will not have ramifications throughout that system escapes me!

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Posted
  • Location: Edinburgh
  • Location: Edinburgh

Grey Cells P.P.

Differing carbon from differing sources is easily traced and the carbon from coal and oil are no exceptions. Seeing as the bulk of the icrease is of these two types I think it safe to assume that we still await the bulk of the CO2 feedbacks 'CO2' that the current warming will drive (which will have their own unique fingerprints too).:wallbash:

And unique fingerprints ae the key issue here, whether they be the isotope of carbon involved, or the spatial and temporal pattern of observed warming (more warming in winter/night, cooling stratosphere), and the wavelengths at which the heat is being trapped (GHG wavelengths). People can argue all they like about whether it's warmed before, or whether it's been X degrees warmer at Y time in the past, but they repeatedly fail to identify the drivers for warming that can explain the observations. It's simply not an adequate excuse to say "it's warmed before", then cite mechanisms that don't fit the fingerprint of observations. It comes down to Mark Serreze's comment in his email to you G-W (linked in Arctic Ice thread) about identifying causes. CO2 has a distinct 'fingerprint', and those fingerprints are all over the current warming. The latest "State of the Climate" report shows this well too.

Wegman? There are better sources of information than someone who has been shown to plagiarise and misrepresent in large chunks - see here and links within:

http://deepclimate.o...in-full-colour/

http://deepclimate.o...id-done-lately/

John Mashey's take, an update due soon too: http://www.desmogblo...ny%20v1%200.pdf

More on fingerprints:

http://www.skepticalscience.com/10-Indicators-of-a-Human-Fingerprint-on-Climate-Change.html

http://www.skepticalscience.com/More-evidence-than-you-can-shake-a-hockey-stick-at.html

sss

Edited by sunny starry skies
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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

I take it, Y.S., that when PDO-ve proves to be milded out by 'other drivers' you'll start to accept that we have had a major influence on the workings of our climate and that these small shifts are, like the melting of the Arctic ice mass in the 50's ,just the start of the full impact of the changes we have driven?

I refer you again to the paper Mark Serreze (head of NSIDC) was kind enough to point us to in his E-Mail to me today;

http://www3.intersci...ETRY=1&SRETRY=0

and ask you where you have issues with these observations.

We are in a changing world and the general direction of that change is undeniable (surely?) merely the scale of those impacts is up for debate. How you can think that to change one part of a closed system will not have ramifications throughout that system escapes me!

Hi G.W,

Yes, if we continue to warm within the -PDO cycle and with low solar activity, I would indeed re-consider my position.

I have always made this clear.

You state that the system is closed ..... but it is not. Cloud feedbacks are a mechanism by which the earths surface (I'm talking oceans here) ability to absorb solar irradiation can be affected, changing the albedo and affecting climate.

How come the earth warms and cools over each and every PDO cycle, you can see simple effects via each and every LA Nina or El Nino.

Check out the Accu-weather Joe laminate floori link on my earlier post.

Time will tell ......... lets see what wins out !! Funny how the models (CPC) are predicting a BIG cool down next year.

Y.S

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

Hi Y.S.!

I've never made any bones about extreme weather events and have also posted that ,following this summers Arctic melt, we are stacking up a whole world of hurt in the N.H. from another very low AO-ve as the Arctic ocean sheds it's accrued heat and modifies the AO along with it (as we saw last year?) over the start of this winter setting the scene for a very nasty Jan/Feb.

I've submitted a long post over on Arctic thread to try and explain ( mainly to Jethro) why I (and others) see the current PDO-ve phase as having started back in 98' so the type of -ve AO we saw last winter piggy backing on PDO-ve can only bring us the type of winter we saw last year (and not a mega 47' or 63'?) somethings amiss surely?

If we truely are mid PDO-ve we only have a few years of it's maximum influence left before it splutters back into neutral and then postive once again and then what?

Most folk agree a resumption in the warming will follow (not that it ever ceased) but most folk do so by looking at the world that was and not by looking at the rapidly changing world that is.

If we can miss 1/2 a PDO-ve phase because it's impacts are so watered down then what of the coming resumption in warming??? will this not be augmented in the same way and make the recent 80'/90's warming look mild by comparison?

How will that further impact global circulation/'natural cycles'???

The time is now Y.S., our globe is changing before us and some folk have taken the respite afforded by 12 years of PDO-ve to say it is not happening.

Kinda like stepping out into the eye of a 'cane and saying "The storms over, time to come out and play........."

Only one mans opinion remember but built around the evidence he see's around him.:mellow:

Edited by Gray-Wolf
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Posted
  • Location: York, North Yorkshire
  • Location: York, North Yorkshire

Hi Y.S.!

I've submitted a long post over on Arctic thread to try and explain ( mainly to Jethro) why I (and others) see the current PDO-ve phase as having started back in 98' so the type of -ve AO we saw last winter piggy backing on PDO-ve can only bring us the type of winter we saw last year (and not a mega 47' or 63'?) somethings amiss surely?

If we truely are mid PDO-ve we only have a few years of it's maximum influence left before it splutters back into neutral and then postive once again and then what?

Hi GW,

I think you will acknowledge that your above statement is pretty much an opinion only (see later posts on the other thread).

Most scientists agree that we have only just entered the -PDO state ....... so lets wait and see shall we ........ Super big Lan Nina doesn't look like 'Milding out' to me !!

Y.S

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

If you look back through the washington series of monthly data you'll see the lowest numerical indices are in 99' where myself (and others) see the regime shift taking place. I know we then went neutral (+ve?) for a while but we have since including this past winter/spring. We cannot just say we are not in the phase because of the occasional switch overs as these are 'normal' within PDO phases.

The other thing is what V.P. highlights in that this is a 'new' area of study and we do not have enough data to truely highlight it's workings (only 5 state changes?) nor infer climate behaviours from it. We do see the phases interact with the Nina/Nino cycles either adding to them or detracting from their impacts so we'll need to see July/Aug figures to see whether PDO-ve will add into the developing Nina.

As we know it'll only be after the next shift that we'll know for sure when the changeover occured:)

Edited by Gray-Wolf
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Posted
  • Location: Edinburgh
  • Location: Edinburgh

Or- G-W, as at least some researchers think, the La Nina feeds into the -ve PDO spatial pattern, ie ENSO drives PDO. But as we've just had a fairly strong El Nino, will that also influence the PDO pattern? We do not have enough data to claim that the PDO spatial oscillation is a regular cycle either, and before predicting it's future state, we need to understand what causes it. Were it truly cyclical, you would expect to have seen a strong negative phase in data before ~1920, but it's not there in the JISAO data (positive if anything between 1900 and 1920. What's to say we're not having another episode of roughly neutral PDO with short periods of negative and positive, albeit the -ve and +ve episodes are of larger magnitude? But all this spatial variability does not hide the fact that the North Pacific has warmed in line with global temperatures throughout the 20th Century, whatever the phase of the PDO.

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Posted
  • Location: Mytholmroyd, West Yorks.......
  • Weather Preferences: Hot & Sunny, Cold & Snowy
  • Location: Mytholmroyd, West Yorks.......

This being so SSS you'd expect more neutral phases of PDO and less severe negative phases? Eventually ,as with Nino, the ocean temps will be so warm as to make all PDO's appear +ve and a constant temp Nino' status!!!

If ocean temps are used as a threshold between various cyclical states then, in the fullness of time, these states will be permanently set in the 'warmer SST state'.

We will ,obviously, have a period of time whilst this state is being approached and this is my 'milding' scenario with PDO-ve states having a higher mean SST than the previous one (as we see through the 1900's -ve PDO's???).

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  • Location: Ireland, probably South Tipperary
  • Weather Preferences: Cold, Snow, Windstorms and Thunderstorms
  • Location: Ireland, probably South Tipperary

This being so SSS you'd expect more neutral phases of PDO and less severe negative phases? Eventually ,as with Nino, the ocean temps will be so warm as to make all PDO's appear +ve and a constant temp Nino' status!!!

If ocean temps are used as a threshold between various cyclical states then, in the fullness of time, these states will be permanently set in the 'warmer SST state'.

We will ,obviously, have a period of time whilst this state is being approached and this is my 'milding' scenario with PDO-ve states having a higher mean SST than the previous one (as we see through the 1900's -ve PDO's???).

Should this stuff be in the oceanic thread???

Anywho, is the PDO more based on the spatial distribution of anomalies, rather than absolutes like ENSO, so that the difference between the cold areas and warm areas determines the strength of the of the oscillation whether it be in a positive or negative phase?

If that is the case, then in a warming world, wouldn't the areas that have the warm anomalies just get warmer, while the areas with the cold anomalies mover closer to average and while changeing the absolute SSTs, not changing the difference between them and thus allowing the oscillations to continue regardless of the baseline SSTs used?

Hope that makes sense!

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