PDA

View Full Version : Ocean Circulation Doesn't Work As Expected



Argos
2009-May-15, 07:50 PM
On Science Daily (http://www.sciencedaily.com/releases/2009/05/090513130942.htm)


The familiar model of Atlantic ocean currents that shows a discrete "conveyor belt" of deep, cold water flowing southward from the Labrador Sea is probably all wet.

Interesting news, of significance for the Climate Change models.

mugaliens
2009-May-16, 05:26 AM
Wow. Incredible. Unheard of. Modern science got actually got something wrong, only to be shown up by science that was more modern. Wow. Incredible...

Tongue in cheek aside, this seriously peaks my interest, Argos, as it demonstrates that we sometimes don't know as much about how various aspects of the climate works as we think we do.

Thanks!

cran
2009-May-17, 12:20 AM
... it demonstrates that we sometimes don't know as much about how various aspects of the climate works as we think we do.

Thanks!

you can extend that to all complex large scale dynamics on and in the Earth - many times we are reminded that things are not as simple as our models ...

korjik
2009-May-17, 07:40 AM
It is too bad that no one around here has ever said (repeatedly) that we dont understand the whole Earth system to be making the sweeping assertions about climate change that are common today.

:P

:D

Trakar
2009-May-17, 08:10 AM
On Science Daily (http://www.sciencedaily.com/releases/2009/05/090513130942.htm)



Interesting news, of significance for the Climate Change models.

Of what significance do you see this making on climate models?

The only primary effect I see, is that it means not as much CO2 is absorbed and taken to deep waters. The thermohaline circulation is important to climate models but primarily in the upper heat transfer branches coming from the equator toward the poles. I don't understand how the deep water circulation patterns are really that important to climate models, but I'd appreciate it if you could explain that importance to me.

Argos
2009-May-18, 06:22 PM
I don't understand how the deep water circulation patterns are really that important to climate models, but I'd appreciate it if you could explain that importance to me.

Perhaps it would be more productive if you could explain to us why ocean circulation patterns are not important to climate models.

publiusr
2009-May-18, 06:44 PM
If there is no conveyor, one might make the case that there is less heat transport and that warming is a worse threat...or perhaps the current results are from an abnormal pattern.

Then too were I to hazard a guess, were I to take a satellite back in time with me to the pre-industrial era, it might see an ozone hole over antarctica after Erebus erupts too. I remember calling the writer of of piece in Popular Mechanics (not Pop sci but pop mech of all things) about the ozone hole. I wondered why it was that the worlds major industrialized nations were largely in the northern hemisphere, and yet the ozone hole was on the opposite pole or something.

He had results from topex poseidon as found by Shoberle IIRC, and told me "Of course, there are no volcanoes in Antarctica."

All this really proves is that we need more interdisciplinary studies.

novaderrik
2009-May-18, 07:28 PM
It is too bad that no one around here has ever said (repeatedly) that we dont understand the whole Earth system to be making the sweeping assertions about climate change that are common today.

:P

:D
that's just crazy talk. we already know everything there is to know, so we should just stop asking so many questions.

Trakar
2009-May-18, 09:53 PM
Perhaps it would be more productive if you could explain to us why ocean circulation patterns are not important to climate models.

Can you point out where I said or even implied that to be the case? Is there some other reason the question I asked you is inappropriate or out of line? You seemed to imply that this finding would make a significant impact on current climate models, I'm just curious why you feel that this particular finding would have the impact you seem to suggest that it should.

Squink
2009-May-18, 10:12 PM
Tongue in cheek aside, this seriously peaks my interest
piques (http://dictionary.reference.com/browse/pique), not peaks.

Ara Pacis
2009-May-19, 01:27 PM
If there is no conveyor, one might make the case that there is less heat transport and that warming is a worse threat...or perhaps the current results are from an abnormal pattern.Or the opposite. For if less heat is transported, then warming might be localized instead of globalized. If the view is of the oceans as a heatsink instead of a heat transport, then perhaps more mixing with deeper water will absorb someof the warming before it affects climate.

Argos
2009-May-19, 01:39 PM
Is there some other reason the question I asked you is inappropriate or out of line?

Not inappropriate. It is only strange, considering that that the whole climate system is forced by a multitude of variables [some - or the majority - of them small]. The findings are about new variables being raised. That´s why I asked you to elaborate on why they should not be taken as important.


You seemed to imply that this finding would make a significant impact on current climate models, I'm just curious why you feel that this particular finding would have the impact you seem to suggest that it should.

I never said there would be a significant impact. But it surely is of significance for the subject under study. By the way, have you read the abstract? The SD article links the original paper on Nature.

Demigrog
2009-May-19, 07:37 PM
Or the opposite. For if less heat is transported, then warming might be localized instead of globalized. If the view is of the oceans as a heatsink instead of a heat transport, then perhaps more mixing with deeper water will absorb someof the warming before it affects climate.

Actually, more mixing with deeper water would support the high-end of CO2 forcing estimates. The more energy the oceans can absorb, the more the full effects of CO2 forcing can be delayed. That is why the IPCC estimate is 3C per CO2 doubling when the historical temperature record only supports 0.7C-1.5C. If we are underestimating the ocean's heat capacity, the forcing could be closer to the IPCC report's 4.5C upper range.

This would mean that as CO2 continues to rise, the oceans would not be able to offset as much of the atmospheric temperature rise.

That said, I don't think the article in the OP tells us much about mixing between ocean layers.

Ara Pacis
2009-May-20, 02:58 AM
Actually, more mixing with deeper water would support the high-end of CO2 forcing estimates. The more energy the oceans can absorb, the more the full effects of CO2 forcing can be delayed. That is why the IPCC estimate is 3C per CO2 doubling when the historical temperature record only supports 0.7C-1.5C. If we are underestimating the ocean's heat capacity, the forcing could be closer to the IPCC report's 4.5C upper range.

This would mean that as CO2 continues to rise, the oceans would not be able to offset as much of the atmospheric temperature rise.

That said, I don't think the article in the OP tells us much about mixing between ocean layers.

I thought the article said something about the streams not being where they are supposed to be and lots of the sensors being diverted off-stream. I took that to mean they either wandered aimlessly in the mid-ocean or maybe ended up circling one of the deep vertical vortices I read about that mix up deep ocean waters.

I admit I'm not a climatologist or an oceanographer, so I'm not making claims but asking questions, but would more deep ocean mixing "fix" carbon through biochemical means instead of dissolution? I know that's a different point from the heat transport/storage, but I figured I'd ask since both might be affected by the OP article's observations.

PraedSt
2009-May-20, 03:07 PM
On Science Daily (http://www.sciencedaily.com/releases/2009/05/090513130942.htm)
Interesting. According to that link the conveyor still exits, it just takes a different route on its southerly travel.
So it's more like blood circulation rather than a conveyor belt.

geonuc
2009-May-20, 03:22 PM
I don't understand how the deep water circulation patterns are really that important to climate models, but I'd appreciate it if you could explain that importance to me.
I would think it somewhat self evident, but perhaps I'm missing your point? Deep-water circulation is part of the circulation as a whole. How ocean water moves about the planet seems intrinsically tied up with climate variations.

lomiller1
2009-May-20, 05:15 PM
The findings are about new variables being raised. That´s why I asked you to elaborate on why they should not be taken as important.

It’s bad practice to assume a newly discovered detail has some important effect unless there is some evidence or reason for thinking it does.

Argos
2009-May-20, 05:19 PM
It’s bad practice to assume a newly discovered detail has some important effect unless there is some evidence or reason for thinking it does.

So, would you prefer to let the new data out of your model?

Trakar
2009-May-20, 06:50 PM
I never said there would be a significant impact.


Sorry, I must have misunderstood;"Interesting news, of significance for the Climate Change models."




But it surely is of significance for the subject under study. By the way, have you read the abstract? The SD article links the original paper on Nature.


Indeed, it is about ocean current circulation, in particular the circulation of warm water eddies in the Labrador Sea and how they tend to diffuse and somewhat moderate the deep, cold water, return circulation from the North Atlantic back toward the equator. I'm sure that this represents new information that should be included in any model which seeks to accurately reflect global environmental conditions. It just sounded to me like your statement was noting that this was somehow representative of a factor that would or should significantly alter our current understandings and/or projections with regards to the climate change trend which our planet is currently experiencing. I was merely interested in why you felt that way.

geonuc
2009-May-20, 07:21 PM
Concerning Argos's OP and the idea that the new findings might be 'significant' for climate change models, I'd point out that the linked article states as much. So why all this questioning of whether this is important or significant?

If you look back to the OP, it is quite benign in that regard. Very curious.

Argos
2009-May-20, 07:39 PM
I was merely interested in why you felt that way.

Are you an anthropologist [just kidding :)]?

My feelings are not important at all.

lomiller1
2009-May-21, 04:10 AM
So, would you prefer to let the new data out of your model?

Who said that? What I said is that it's not scientifically or logically sound to say "there is new evidence, I have no basis for claiming it changes anything but we must assume it overturns the science as it currently stands unless you can prove it doesn't"

Trakar
2009-May-23, 04:07 PM
I would think it somewhat self evident, but perhaps I'm missing your point? Deep-water circulation is part of the circulation as a whole. How ocean water moves about the planet seems intrinsically tied up with climate variations.

Circulation, as a whole, has an evident relevence to climate models. Whether, or not, the deep water branch of that circulation takes the form of a single current "belt," or a more diffuse "tributary" flow (or any number of other possibilities, so long as it accomplishs the same general task), is not so obvious in its effect upon those same climate models, at least to me. I welcome, however, the opportunity to learn that which I do not know.

Trakar
2009-May-23, 04:22 PM
Concerning Argos's OP and the idea that the new findings might be 'significant' for climate change models, I'd point out that the linked article states as much. So why all this questioning of whether this is important or significant?

If you look back to the OP, it is quite benign in that regard. Very curious.

Popsci articles say lots of things that may or may not be strictly accurate, or at the least, are subject to multiple interpretation. Argos also referenced the Nature abstract and implied a personal level of consideration beyond the linked article's information of how he felt this finding to be of especial interest to climate modelling. Either through poor wording on his part, or my own misunderstandings of his words, this now appears not to be the case. If there's nothing new to add, it is still an interesting finding and I thank him for bringing it to my attention and sharing!

Trakar
2009-May-23, 04:25 PM
Are you an anthropologist [just kidding :)]?


LOL, In the most broad aspect of the term,...aren't we all?



My feelings are not important at all.


I only mentioned them because you brought them up in your initial post.

cran
2009-May-24, 10:17 PM
Circulation, as a whole, has an evident relevence to climate models. Whether, or not, the deep water branch of that circulation takes the form of a single current "belt," or a more diffuse "tributary" flow (or any number of other possibilities, so long as it accomplishs the same general task), is not so obvious in its effect upon those same climate models, at least to me. I welcome, however, the opportunity to learn that which I do not know.
Varying the path (and by extension, either the travel time or transport rate), and/or diffusing or dividing the water mass (which has effects on thermal and chemical properties), of itself questions whether "the same general task is accomplished" in the manner described or predicted by the models -
that's why the finding is "significant" with respect to the models ...
it doesn't change reality, it challenges our attempts to describe it ...

Trakar
2009-May-25, 05:08 PM
Varying the path (and by extension, either the travel time or transport rate), and/or diffusing or dividing the water mass (which has effects on thermal and chemical properties), of itself questions whether "the same general task is accomplished" in the manner described or predicted by the models -
that's why the finding is "significant" with respect to the models ...
it doesn't change reality, it challenges our attempts to describe it ...

The only thing quoted in the article is the varying of the path and method, the "by extension" elements you suggest are not supported in either the article or the general observed and collected data which form the basis of the models you seem to be talking about. The same general task is accomplished, because the end results are (and have long been) already known. By analogy it is rather like knowing the basic list of ingredients and having a slice of cake and trying to figure out how the ingredients were turned into that slice of cake. The surface effects and expressions produced by the currents have long been documented and recorded, the general mechanisms of that half of the system have been charted and recorded rather extensively for the last several centuries. Now, it appears that the return, deep water system is more complex than the surface circulation system, but the end result is still the same as it was before we understood the nature of the deep water system.

So again, I am left wondering of what great significance this issue is to current climate models? The climate models are, for the most part, based upon the end results not the particular mechanism by which that result is achieved. Unless you can demonstrate, or propose a method by which this new understanding will dramatically vary the end-result as conditions move forward, and a means to test this proposal, then it boils down to an interesting difference, which really makes little or no difference at all existing climate models.

lomiller1
2009-May-25, 05:32 PM
that's why the finding is "significant" with respect to the models ...
it doesn't change reality, it challenges our attempts to describe it ...

All models are wrong, some are useful.

What is it about this particular discrepancy that makes you suspect it will quantitatively change the models output?

No doubt this information will be worked into the models eventually and we won’t need to make this type of educated guess. Until then, simply pointing out the model isn’t perfect gets us nowhere, no model is ever perfect. Unless you have a reasoned argument for why a particular imperfection should make a quantitative difference in the model output you are bringing nothing whatsoever to the table.

eburacum45
2009-May-25, 07:13 PM
If the circulation of water in the North Atlantic does not work as previously expected, does that make the possibility of a Younger Dryas-type event more or less likely?
http://science.nasa.gov/headlines/y2004/05mar_arctic.htm?list7433

Argos
2009-May-25, 07:42 PM
It´s beyond me why my humble phrase at the end of the OP is attracting that much of nitpick. The fact is that climate models rely on the North Atlantic circulation as a major input. Any change in that data set will impact the models. Seems so simple.

lomiller1
2009-May-25, 10:05 PM
Again, you really need to back up that claim with something more then “it seems like it should” because I can see no reason why climate models should have any dependency on what happens to the water after it sinks, nor is it my responsibility to come up with reasons why it may.

You are the one proposing deep ocean circulation patterns should have a significant impact on climate models so you are the one that needs to give a reasoned justification of the claim

lomiller1
2009-May-25, 10:10 PM
If the circulation of water in the North Atlantic does not work as previously expected, does that make the possibility of a Younger Dryas-type event more or less likely?
http://science.nasa.gov/headlines/y2004/05mar_arctic.htm?list7433

Possible alternatives to a meltwater pulse as the cause of the Younger Dryas aside I don’t really see how it would make a difference. The meltwater pulse theory says the location of the gulf stream subsiding could have been altered by changes in salinity, causing rapid cooling in Europe and parts of North America.

I don’t see how these changes in deep ocean currents would have any impact on where the water subsides, if anything the reverse is more likely to be the case.

geonuc
2009-May-25, 10:24 PM
You are the one proposing deep ocean circulation patterns should have a significant impact on climate models so you are the one that needs to give a reasoned justification of the claim
And I'll say again- the article stated as much. Argos is not proposing anything other than that an article was published that might be of interest to us.

lomiller1
2009-May-26, 12:00 AM
geonuc, your repeating yourself doesn’t make you statement any more valid. The article does not suggest this is of any importance for climate models and there has been no reason given as to why it should. Argos, and several others, however, continue to insist it should but refuse to give any reason why.

orionjim
2009-May-26, 01:38 AM
All models are wrong, some are useful.
[…]


I was taught that when you use someone’s quote that it is proper to give that person credit. In this case the person that made the quote was George E. P. Box. George Box and Stu Hunter professors and co-authors were mentors of mine. Along with William G. Hunter they wrote “Statistics For Experimenters”, An Introduction to Design, Data Analysis and Model Building.



[…]
What is it about this particular discrepancy that makes you suspect it will quantitatively change the models output?
[…]


You won’t know that until you alter the model.



[…]
No doubt this information will be worked into the models eventually and we won’t need to make this type of educated guess. Until then, simply pointing out the model isn’t perfect gets us nowhere, no model is ever perfect. Unless you have a reasoned argument for why a particular imperfection should make a quantitative difference in the model output you are bringing nothing whatsoever to the table.

The only person making the educated guess is you, everyone else is referring to the article.



"Everybody always thought this deep flow operated like a conveyor belt, but what we are saying is that concept doesn't hold anymore," said Duke oceanographer Susan Lozier. "So it's going to be more difficult to measure these climate change signals in the deep ocean."
And since cold Labrador seawater is thought to influence and perhaps moderate human-caused climate change, this finding may affect the work of global warming forecasters.

lomiller1
2009-May-26, 02:28 AM
The excerpt you provide from the article say nothing, *zero* about climate models. In fact climate models are not mentioned in the article at all. If someone comes up with a reason how or why this could impact climate models it could it may be worth discussing but at present all we have are people throwing around tangential facts and insisting they overturn established science.

As for the quote, clearly I thought people here would be familiar it and it’s provenance, but perhaps your right I should have take the less well read posters into account.

orionjim
2009-May-26, 02:56 AM
The excerpt you provide from the article say nothing, *zero* about climate models. In fact climate models are not mentioned in the article at all. If someone comes up with a reason how or why this could impact climate models it could it may be worth discussing but at present all we have are people throwing around tangential facts and insisting they overturn established science.

As for the quote, clearly I thought people here would be familiar it and it’s provenance, but perhaps your right I should have take the less well read posters into account.

Computer models attempt to model reality. To do this you take all you know about reality and build a model and check it against reality. If you find that what you think you know about reality is not true or different than what you thought, then the model needs to take this revised vision or knowledge into account.

The article is saying what we thought we knew wasn’t correct, implying any model based on the older knowledge might have problems. Remember the only thing the modelers have to construct their models is the mental image of reality with the data. This mental image is constantly changing as more is learned about reality. As the mental image changes the models need to change.

Yes, some skeptics are implying that this makes all of the climate models useless. But nothing could be farther from the truth. All it means it the models will get better.

Just remember the model is trying to model reality, it isn’t reality. If it was then it wouldn’t be a model.

Instead of trying to defend the models that might or might not have problems, you should take the time to understand what the models do and why George Box would make a statement like he did.

lomiller1
2009-May-26, 04:03 AM
Models, computer or otherwise, focus on the most relevant bits and ignore the rest. Instead of waving your hands about, show us that this is one of the relevant bits of a climate model.

Trakar
2009-May-26, 05:36 AM
Models, computer or otherwise, focus on the most relevant bits and ignore the rest. Instead of waving your hands about, show us that this is one of the relevant bits of a climate model.

A difference that makes no difference, is no difference of significance.

The current Climate models are based upon the end result effects of the circulation, not upon the precise manner in which the thermohaline circulation accomplishes those results. Unless it can be demonstrated that this new understanding of the deep-water leg of this circulation somehow significantly impacts the cumulative data upon which the models are based, it is just another interesting aspect of ocean currents.

As the article doesn't really refer to how such would impact climate models, I was interested in how Argos thought that this would be of significant import to those models, now it seems that he really doesn't have any considered opinion on the topic, or at the least isn't willing to share it here.

At a quick glance it would seem to make the global thermohaline system seem much more fragile and unstable. Now if this is so, and the global conveyor system were to break down, into smaller, more localized current systems, then yes, that would undoubtably have an impact on the Earth's climate and our climate models. But this isn't really mentioned in the article, nor any of the other discussions here in response to the article link. But that is just a lightly considered speculation, anyone with a more considered opinion or rebuttal is welcome to present their case!

lomiller1
2009-May-26, 06:12 AM
The current Climate models are based upon the end result effects of the circulation, not upon the precise manner in which the thermohaline circulation accomplishes those results.

Not quite the end result I think. My understanding is that surface currents are quite important. The deep ocean return mechanism, however doesn't interact with the atmosphere so the claim it significantly alters the atmosphere seems more then a little questionable.

geonuc
2009-May-26, 09:50 AM
geonuc, your repeating yourself doesn’t make you statement any more valid. The article does not suggest this is of any importance for climate models and there has been no reason given as to why it should.
Correct - my statement remains as valid as before.

How do you interpret this quote from the article? To me, it suggests an effect on our climate models.

"That means it is going to be more difficult to measure climate signals in the deep ocean," Lozier said. "We thought we could just measure them in the Deep Western Boundary Current, but we really can't.

orionjim
2009-May-26, 01:20 PM
Models, computer or otherwise, focus on the most relevant bits and ignore the rest. Instead of waving your hands about, show us that this is one of the relevant bits of a climate model.

You make it sound like they're trying to model an ostrich.

Argos
2009-May-26, 01:45 PM
geonuc, your repeating yourself doesn’t make you statement any more valid. The article does not suggest this is of any importance for climate models and there has been no reason given as to why it should. Argos, and several others, however, continue to insist it should but refuse to give any reason why.

Geonuc has interpreted my intervention the right way. It was supposed to be a comment, derived from the contents of the article. It´s not my hypothesis, nor am I intending to teach anyone. Climate models are known to be sensitive to minor changes in the inputs. Hence I presume that small changes in the ocean circulation may have the models display a different picture of the long term evolution of the system.

lomiller1
2009-May-26, 02:38 PM
Agros, as pointed out, your comment has no basis whatsoever on the information in the article.

Oh and your claim that climate models are “known to be sensitive to minor changes in the inputs” is equally unsupported. It’s also wrong; you seem to be confusing climate models with weather models.


Geonuc, the only thing “climate model” has in common with “climate signal in the deep ocean” is that they both contain the word “climate” Are you seriously saying you thought they meant the same thing because they had one word in common?

Demigrog
2009-May-26, 02:56 PM
The excerpt you provide from the article say nothing, *zero* about climate models. In fact climate models are not mentioned in the article at all. If someone comes up with a reason how or why this could impact climate models it could it may be worth discussing but at present all we have are people throwing around tangential facts and insisting they overturn established science.

As for the quote, clearly I thought people here would be familiar it and it’s provenance, but perhaps your right I should have take the less well read posters into account.

The article mostly mentions the impact of ocean circulation patterns on its ability to act as a CO2 sink. Obviously, if the ocean absorbs more or less CO2 than we expect we're going to have different climate predictions, but the effect is only indirect through atmospheric CO2 concentrations.

The article says nothing about thermal transfers, IIRC, that would have a direct effect on climate models.

lomiller1
2009-May-26, 03:50 PM
Demigrog, I don’t disagree but the issue being raised is that some people have made the claim this throws a wrench into climate models, when there is no evidence whatsoever to suggest it does.

The big question I see this study raising is how to study deep ocean heat content, and it may even raise the uncertainty in ocean heat content estimates.

geonuc
2009-May-26, 03:59 PM
Geonuc, the only thing “climate model” has in common with “climate signal in the deep ocean” is that they both contain the word “climate” Are you seriously saying you thought they meant the same thing because they had one word in common?

No, I didn't equate the two because they both contain the word 'climate'. That's rather insulting.

Read the OP again. Essentially, Argos stated "This is interesting and I think climate researchers will think it's interesting, too." Perhaps you're hung up on the use of the phrase "of significance"? In this context, I took it as a synonym for "of interest". And the article definitely seems to agree with that very general notion:

"And since cold Labrador seawater is thought to influence and perhaps moderate human-caused climate change, this finding may affect the work of global warming forecasters."

There's more, but I assume you read the article and I'm not going to quote the entire thing. Half the article seems to be about how this might affect how we think this particular (and important) deep water current operates and if it might affect global warming research.

Another article (http://www.physorg.com/news161439846.html) on the same topic goes slightly further:

"Since forecasters say effects of global warming are magnified at higher latitudes, that makes the Labrador Sea an added focus of attention. Surface waters there absorb heat-trapping carbon dioxide from the atmosphere. And a substantial amount of that CO2 then gets pulled underwater where it is no longer available to warm Earth's climate.

"We know that a good fraction of the human caused carbon dioxide released since the Industrial revolution is now in the deep North Atlantic" Lozier said. And going along for the ride are also climate-caused water temperature variations originating in the same Labrador Sea location.""

nauthiz
2009-May-26, 04:28 PM
Just as a meta-comment:

It's true that there are some excitable folks out there who seem to be quick to jump to the conclusion that every new discovery about how the climate works invalidates all previous work in climate science. It's also true that there are some folks who seem to believe that nothing in climate science can be trusted or even conditionally accepted until our understanding reaches a point where every molecule can be accounted for. (Maybe that's not what they're saying now, but that seems to be the direction in which the goalpost keeps moving, so it's hard not to make the inference.) Both these memes tend to underpin a lot of frustrating and irrational statements.

However, it is also frustratingly irrational to respond to such ideas by just circling the wagons. We don't know everything about how the climate works, and new discoveries are constantly being made. Many of these do have an impact on our model of the planet - in fact, these discoveries are usually being made by people whose express goal is to improve on that model. It may be unscientific to make wild jumps to conclusions every time a new press release comes out, but it is far, far more unscientific to instincutally perceive any new scientific discovery as an attack on the orthodoxy. Scientific orthodoxies are supposed to adopt and adapt to new discoveries. Rigidity is a better tool for politics and pseudoscience.

Ara Pacis
2009-May-26, 04:43 PM
Agros, as pointed out, your comment has no basis whatsoever on the information in the article.

Oh and your claim that climate models are “known to be sensitive to minor changes in the inputs” is equally unsupported. It’s also wrong; you seem to be confusing climate models with weather models.


Geonuc, the only thing “climate model” has in common with “climate signal in the deep ocean” is that they both contain the word “climate” Are you seriously saying you thought they meant the same thing because they had one word in common?

Or is it the difference in meaning between climate model and climate change model? If I follow the logic correctly, the discovery makes no difference WRT a climate model because the end result of the process is already known, so knowing more detail about it will not change that result. However, the discovery may warrant a change WRT a climate change model because the end result and some aspects of that process are not yet known.

Demigrog
2009-May-26, 05:23 PM
Demigrog, I don’t disagree but the issue being raised is that some people have made the claim this throws a wrench into climate models, when there is no evidence whatsoever to suggest it does.

This new data isn't screwing up the models; it is just tweaking the constants a bit.



The big question I see this study raising is how to study deep ocean heat content, and it may even raise the uncertainty in ocean heat content estimates.
Well, the original study (preprint available (http://www.google.com/url?sa=t&source=web&ct=res&cd=8&url=http%3A%2F%2Fwww.uwpcc.washington.edu%2Fdocume nts%2FPCC%2Floziernaturesubmission2008.pdf&ei=UCEcSt-dM9-ptgeA7dnoDA&rct=j&q=Interior+pathways+of+the+North+Atlantic+meridion al+overturning+circulation&usg=AFQjCNEU-r7mW-NUJOGmfDmBEsr2ulI8NQ)) makes no conclusions at all beyond the circulation patterns itself. Any questions raised have so far been pure commentary and not peer reviewed, and certainly not quantitative.

Even if the circulation models have been totally wrong all along, there needs to be analysis to see if the difference is significant in terms of heat capacity of the ocean. For one thing, the bulk of the heat is trapped in the upper layers, and deep-ocean circulation patterns may not really be relevant to mixing between upper and lower layers.

I do think the new study shows just how inadequate our deep-ocean data is.

lomiller1
2009-May-26, 05:46 PM
Or is it the difference in meaning between climate model and climate change model? If I follow the logic correctly, the discovery makes no difference WRT a climate model because the end result of the process is already known, so knowing more detail about it will not change that result. However, the discovery may warrant a change WRT a climate change model because the end result and some aspects of that process are not yet known.

I’m not sure what you mean by “climate change model” can be no single model of climate change because there is an intelligent agent involved. When an outcome depends on the actions of an intelligent agent like humans you typically can’t develop a physical model for it.

Climate models look at some feature of the climate (global temperature for example) and say if this parameter (atmospheric CO2 for example) changes what will the outcome be.

There are many other complex systems that are studied ion their own right and may have a big impact on future clime, ice dynamics, deep ocean circulation patterns, permafrost, methane hydrate deposits, etc. These each have their own studies and models that are typically complete separate from what is referred to as climate models.

lomiller1
2009-May-26, 06:01 PM
Going back to the OP for a second, here is exactly what it said:



Interesting news, of significance for the Climate Change models.


Interesting, perhaps. “Of significance to climate models” is totally unsupported by the text of the article. When challenged, the OP refused, and continues to refuse to present any argument in favor of the claim.

Furthermore several other people who have insisted the claim is true similarly refuse to present any argument in favor of it. It seems their preferred tactic is to simply repeat the claim and try to sidetrack any discussion over it’s validity in the hope people will stop challenging it.

Clearly they are annoyed that I continue to challenge them to provide some form of support for the claim, but I don’t see that as good enough reason to simply let an unsupported claim stand. So, once again I give those of you who want to support this claim the opportunity to present their arguments in favor of it

Argos
2009-May-26, 06:16 PM
Interesting, perhaps. “Of significance to climate models” is totally unsupported by the text of the article. When challenged, the OP refused, and continues to refuse to present any argument in favor of the claim.

Much ado about semantics. It´s just my opinion. Move on [make it "of interest to"]. :)

Ok, I take back my comment in exchange for a real discussion of the implications of the study.

NickW
2009-May-26, 06:45 PM
I took the word "significance" to mean "interest". I think you took Argos out of context here, and made a mountain out of a mole hill.

Trakar
2009-May-26, 07:25 PM
However, it is also frustratingly irrational to respond to such ideas by just circling the wagons. We don't know everything about how the climate works, and new discoveries are constantly being made. Many of these do have an impact on our model of the planet - in fact, these discoveries are usually being made by people whose express goal is to improve on that model. It may be unscientific to make wild jumps to conclusions every time a new press release comes out, but it is far, far more unscientific to instincutally perceive any new scientific discovery as an attack on the orthodoxy. Scientific orthodoxies are supposed to adopt and adapt to new discoveries. Rigidity is a better tool for politics and pseudoscience.

For my own part, I was simply curious about what issues of "significance" the OP perceived in this article and discovery with regards to current climate models. My initial response could have been easily and quickly addressed with either a considered opinion (or even a lightly considered speculation as per the counter example I provided), or a simple statement addressing my interpretation of statement (either admitting ignorance or simply clarifying his remarks to eliminate my confusion as to his words meanings). Instead I get a response which implies that the published paper upon which the article is based clarifies this issue with respect to the impact upon climate models, and that there is something improper with my questioning, that I should read the article and explain why I have some unspecified problem with the finding rather than ask him to explain and discuss his remarks. However, a quick read through of the actual published paper, indicates that it has nothing to do with climate models and does not discuss or speculate upon this findings implications for current climate models in any detail either directly or indirectly that I can tell.

Now, days later, after the prompting by another poster, the OP has revised his position and seems to be saying that his remarks that this would be significant to climate models, should have been interpreted as meaning that he interpreted the article's content to imply that this finding should have been of interest to climate modellers.

Again, I probably would have been curious and asked for more details, and things may have turned out much the same, but the issue isn't, at least on my part, about circling the wagons, I am merely curious about what aspects of this finding might significantly impact current climate models and/or the projections dependent upon those models ---- that is the discussion and understanding I am seeking. <edit> I am grateful (whatever his intentions) to the OP for bringing this information to the board's attention, and still hope to derive a useful discussion, exploration and understanding of the subject matter from the thread before it devolves to a complete food-fight.

Trakar
2009-May-26, 07:32 PM
Ok, I take back my comment in exchange for a real discussion of the implications of the study.

Excellent!
What is your considered (lightly or in depth) opinion with regards to any important effect this new understanding would have upon the planet's climate, or our models of the climate?

lomiller1
2009-May-26, 08:01 PM
I took the word "significance" to mean "interest".

Whatever you want to call it someone needs to propose some implication for climate models before that implication can be discussed. If the people trying to connect this paper to climate models want to retract that particular claim then great, if they want to provide some support for the claim then that great as well.

So far though, all we have is someone saying “this has very important implications, I can’t say what those may be but let’s discuss them anyway”. How can you hold a discussion around that?

lomiller1
2009-May-26, 08:04 PM
Excellent!
What is your considered (lightly or in depth) opinion with regards to any important effect this new understanding would have upon the planet's climate, or our models of the climate?

A much better reply then my own, I think

geonuc
2009-May-26, 09:01 PM
So far though, all we have is someone saying “this has very important implications, I can’t say what those may be but let’s discuss them anyway”. How can you hold a discussion around that?
Would you mind pointing out where you got those words you have quoted above? Would it be the same poster who said this "throws a wrench into climate models"? If not, please identify that person as well.

ETA: On second thought - never mind. I'll respect Argos' wish that the thread get past this.

lomiller1
2009-May-26, 09:25 PM
Since the OP has already admitted and retracted his claims about models I see no reason to discuss it further. For the rest, if you don’t care for my characterization feel free to go ahead and say exactly what you think is important about this article. I’ve been asking for this for two pages now so it’s not like I’ll object.

Trakar
2009-May-26, 09:46 PM
I do understand that we are a group of many different time schedules and varied real life demands, so while I eagerly anticipate learning that which I do not know and adapting that which I do know through the exchange of information with other intelligent and thoughtful individuals in engaging discussion, perhaps this little excerpt of a statement by Dr Susan Lozier (one of the paper's principle authors) in an exchange with Dr Bill Chameides will help to stimulate further discussion:



"It has been quite surprising (and dismaying) that some global warming skeptics have argued that our research 'means that all the current climate prediction models are significantly wrong.'"

"This statement is clearly nonsense. Apparently, by stating that the conceptual model of the lower limb of the overturning circulation as a conveyor belt is broken, the skeptics took this to mean that there is no overturning circulation. From there, they concluded that all climate prediction models are wrong, an astoundingly erroneous interpretation of our work!"


Dr. Bill Chameides is the dean of Duke's Nicholas School of the Environment and a member of the National Academy of Sciences. He blogs regularly at theGreenGrok.com (http://www.nicholas.duke.edu/thegreengrok).

Without comment upon the "skeptical" blogosphere comments, as I generally don't have the time or inclination to surf around, particularly to such politically contrived sites, it seems to me that one of the paper's authors is arguing against any change of "significance" (there's that word again, I wonder if we could source that to the denialist blogosphere?) by these findings with respect to current climate models. Despite this repudiation, I believe that there might be some room for difference of opinion, and I would like to understand any alternative explanations and considerations.

Ara Pacis
2009-May-27, 01:19 AM
Since the OP has already admitted and retracted his claims about models I see no reason to discuss it further. For the rest, if you don’t care for my characterization feel free to go ahead and say exactly what you think is important about this article. I’ve been asking for this for two pages now so it’s not like I’ll object.

Well, I thought it prompted more questions which might lead to new speculations, but that's all it is, questions and speculations based on a new observation, not a hypothesis.

Argos
2009-May-27, 03:07 PM
Excellent!
What is your considered (lightly or in depth) opinion with regards to any important effect this new understanding would have upon the planet's climate, or our models of the climate?

However marginal the effect may be, it seems to indicate that the models are going to be better henceforth, since they were running on flawed data so far. The findings make our understanding of the oceanic heat transport better, so I expect refinements in the climate models, especially climate change models.

Argos
2009-May-27, 03:36 PM
Since the OP has already admitted and retracted his claims about models I see no reason to discuss it further.

Why not? Even if I´m wrong the subject can yield an interesting discussion. It´s not about my opinions. As I said, I´m making no assumptions or hypothesis. It was just a wrong word choice. Excuse me, but I think you´re taking too hard on me. Such aggressivity is uncalled for. :)

Trakar
2009-May-27, 04:45 PM
However marginal the effect may be, it seems to indicate that the models are going to be better henceforth, since they were running on flawed data so far. The findings make our understanding of the oceanic heat transport better, so I expect refinements in the climate models, especially climate change models.

I suspect that you may well be correct in this consideration, particularly with regards to longer term projections. In general, my take from this paper is that there is no real alteration in thermal transport mechanisms or effects, but there may be some effect in the CO2 sink capabilities, particularly with respect to longer term sequestration of absorbed CO2 in the deep-water leg of the thermohaline system. Apparently we can't depend upon the oceans remaining to be a sink for up to a third of human generated emissions into the future, as it has done up until the present.

geonuc
2009-May-27, 05:05 PM
I'm no oceanographer, but wouldn't the change be realized in the deep water data we have been using, not at the northern latitudes, but in the tropics? In other words, we've been taking data at the southern end of this deep-water current under the assumption that it represented the bulk of the Labrador current. Turns out that's not the case, so we need to obtain (or use) data from the various other places that we now think the current flows to.

There are sure to be other implications. Deep water currents don't stay that way - they eventually rise somewhere, right? We now know that some data we attributed to other rising water actually represents rising Labrador current water, in part or whole. Probably the transport time will have to be adjusted.

Trakar
2009-May-27, 05:28 PM
I'm no oceanographer, but wouldn't the change be realized in the deep water data we have been using, not at the northern latitudes, but in the tropics? In other words, we've been taking data at the southern end of this deep-water current under the assumption that it represented the bulk of the Labrador current. Turns out that's not the case, so we need to obtain (or use) data from the various other places that we now think the current flows to.

There are sure to be other implications. Deep water currents don't stay that way - they eventually rise somewhere, right? We now know that some data we attributed to other rising water actually represents rising Labrador current water, in part or whole. Probably the transport time will have to be adjusted.

This new data does not shorten the conveyor process to my understanding, it merely changes the pathway. Instead of a concentrated, steady current, it is more like a diffuse capillary flow, think of a river tributary system in reverse.

The major problem is that the overturn possesses a millenial lag, and while our measurements of atmosphere are fairly solid over the last century, the time lag of waiting for it to upwell once again so that we can compare the characteristics of the water that sank to the characteristics of the water that upwells, is still well into the future. Deep water sampling, is possible, particularly once the flow patterns are better understood.

Ara Pacis
2009-May-27, 05:28 PM
Deep water currents don't stay that way - they eventually rise somewhere, right?Or are there two hydrospheres with less interaction than we might think?

lomiller1
2009-May-27, 05:58 PM
However marginal the effect may be, it seems to indicate that the models are going to be better henceforth, since they were running on flawed data so far.


It’s the surface behavior that climate models depend on, and they are already working off the best available research on how those surface currents behave. Deep ocean return will never trump the actual observations in the upper ocean that climate models depend on because whatever new theories arise for the deep ocean must fit with surface observations. Over the long term this could be significant for predicting how ocean currents may change but even this doesn’t impact the models themselves, just the scenarios you choose to run.

What the article does point out is that this may have impact for detecting climate signals in the ocean. IOW, it may be important when you go out to physically measure changes in ocean heat content, which should allow for more accurate data and help resolve some of the discrepancies in the different methods of measurement.

It’s worth pointing out that with the current generation of models discrepancies between measured and molded ocean heat changes In the last few rounds of climate model predictions of ocean heat content, vs the measured values the models won out. I.E. the discrepancy turned out to be caused by errors in measurement rather then deficiencies in the models.

nauthiz
2009-May-27, 06:11 PM
It's also kind of neat to see how researchers are starting to discover new climate mechanisms by noticing unexpected results in the model runs and then collecting empirical data to confirm that the same thing happens in the real world.

(Though I suppose it's not particularly unique, since every theory is supposed to make testable predictions like that.)

Ara Pacis
2009-May-27, 06:33 PM
It’s the surface behavior that climate models depend on, and they are already working off the best available research on how those surface currents behave. Deep ocean return will never trump the actual observations in the upper ocean that climate models depend on because whatever new theories arise for the deep ocean must fit with surface observations. Over the long term this could be significant for predicting how ocean currents may change but even this doesn’t impact the models themselves, just the scenarios you choose to run.

But might there be a GW tipping-point after which the deep ocean becomes relevant? I'm not sure I could speculate on a mechanism by which this would be important on human timescales. But long-term, I would think that large sea-level changes would alter the scope, if not the dynamics, of both the upper and deep ocean.

lomiller1
2009-May-27, 09:42 PM
That’s a possibility, if fact there some potential tipping points have already been identified, and there is always the possibility of more. Permafrost, Greenland/Antarctic ice caps, methane hydrate deposits, CO2 uptake by the oceans are all examples of possible tipping points.

If we do hit a tipping point all bets are off because by their very nature they mean global climate will settle into a completely different range, and in many cases we simply lack the empirical data to know what that range will be. This is why tipping points tend to scare climate scientists.

On the surface of the issue though, I don’t see what tipping point could arise from this new information. If it does have long term implications for surface behavior, I’d speculate that those would occur well into the future where model uncertainty is already high.

Trakar
2009-May-27, 10:47 PM
On the surface of the issue though, I don’t see what tipping point could arise from this new information. If it does have long term implications for surface behavior, I’d speculate that those would occur well into the future where model uncertainty is already high.

Again, as a speculation, and based upon some other discussion fo potentials that I've read concerning the THC, if this system is indeed as weak as this and other reports suggest, it is possible that the global conveyor system could break down into isolated local currents. This would potentially have several global climate impacts.

lomiller1
2009-May-28, 12:25 AM
The surface circulation is primarily wind driven, and that’s a function of the planets rotation and the position of the continents it’s not fragile at all, in fact it’s almost as certain as you can get.

Trakar
2009-May-28, 02:20 AM
The surface circulation is primarily wind driven, and that’s a function of the planets rotation and the position of the continents it’s not fragile at all, in fact it’s almost as certain as you can get.


I'm certain that winds play a major role in establishing and maintaining many ocean currents, but I'm unclear on how it acts as the primary driver of the Thermohaline circulation currents, could you please explain this in more detail?