A Looming Climate Shift??

[JimD]

Readers should find the skeptical Science article in the below link very interesting.  It discusses the slow down in atmospheric warming over the last decade (the missing heat went into the deep oceans), what is causing it and indicates that it may be about to reverse trends.

http://www.skepticalscience.com/A-Looming-Climate-Shift-Will-Ocean-Heat-Come-Back-to-Haunt-us.html

[BornFromTheVoid]

Here's the Meehl et al. paper

Externally forced and internally generated 5 decadal climate variability associated with 6 the Interdecadal Pacific Oscillation
 
Abstract: Globally averaged surface air temperatures in some decades show rapid increases (accelerated warming decades) and in other decades there is no warming trend (hiatus decades). A previous study showed that the net energy imbalance at the top of atmosphere of about 1 Wm-2 is associated with greater increases of deep ocean heat content below 750m during the hiatus decades while there is little globally averaged surface temperature increase or warming in the upper ocean layers. Here we examine processes involved with accelerated warming decades, and address the relative roles of external forcing from increasing greenhouse gases and internally generated decadal climate variability associated with Interdecadal Pacific Oscillation (IPO). Model results from CCSM4 show that accelerated warming decades are characterized by rapid warming of globally averaged surface air temperature and greater increases of heat content in the upper ocean layers and less heat content increase in the deep ocean, opposite to the hiatus decades. In addition to contributions from processes potentially linked to Antarctic Bottom Water (AABW) formation and the Atlantic Meridional Overturning Circulation (AMOC), the positive phase of the IPO, adding to the response to external forcing, is usually associated with accelerated warming decades. Conversely, hiatus decades typically occur with the negative phase of the IPO, when warming from the external forcing is overwhelmed by internally generated cooling in the tropical Pacific. Internally generated hiatus periods of up to 15 years with zero global warming trend are present in the future climate simulations. This suggests that there is a chance the current observed hiatus could extend for several more years.

http://www.cawcr.gov.au/staff/jma/Decadal.trends.Meehl.JClim.2013.pdf

[deep octopus]

Pacific Decadal Oscillation (PDO) seems to be gradually moving into a warm phase.


This is apparent compared to the beginning of the year.


University of Washington's PDO Index put May 2013 in positive territory (albeit 0.08) for the first time since May 2010, during an exiting El Niño. It's hard to tell yet whether this is just a false bottom in the midst of a chronically negative PDO, or a reversal that will hold. ENSO is expected to go neutral again in 2014.

I can't remember the exact source at the moment and will try to check later, but in addition to warm PDO phases encouraging El Niños and vice versa, a warm PDO is shown to actually amplify the atmospheric-ocean teleconnections and Nino 3.4 SST anomalies during El Niño. It's one possible reason, I think, the El Niño that was supposed to arrive in 2012-2013 never came to fruition. A cool PDO would have suppressed its strength. So it's going to take maybe another year or two before 2010 is surmounted as the hottest year. That we sit on the cusp of a warm PDO may be the start to the "climate shift" from the tropical perspective, but that waits to be seen. Needless to say, it's inevitable. The other key climate shift I'm obviously worried about coming to life very soon is the collapse of Arctic sea ice...

[BornFromTheVoid]

The difference with the +ve PDO from May 2010 and this year is quite interesting.

[JimD]

Looking at NOAA generated PDO graphs it seems as if we are basically on the limit of 15 years right now.  It looks like the current negative phase started right after 1998 and has remained negative, with very small positive periods since.  If the paper is accurate the shift should happen  very soon.

It seems noteworthy that the 'accelerated warming' decades are at least a plus 0.41C per decade.  So if we hit a sustained positive phase temps are going to jump.

For the accelerated warming decades the authors choose decades where the global surface warming is at least 0.41°C per decade (around twice the observed warming over the last few decades based on GISTEMP).

[pikaia]

From the Skeptical Science article:

"...The transport of ocean heat to depths, and to the poles, will drastically slow down, ..."

That sounds like the Arctic melting will slow down as the rest of the world gets warmer, paradoxically. Is that correct?

[JimD]

pikaia,

From the Skeptical Science article:

"...The transport of ocean heat to depths, and to the poles, will drastically slow down, ..."

That sounds like the Arctic melting will slow down as the rest of the world gets warmer, paradoxically. Is that correct?

That is a good question.  I think (and it will be interesting to see what others say) that the answer is no.  A positive IPO will not result in a slowing Arctic melting because the ocean transport of heat to the arctic is primarily driven by the thermohaline circulation and the hottest part of that circulation is the current flowing up the east coast of North America coming directly from those much hotter tropic waters caused by the positive IPO.  So a positive IPO would make the melting worse.   But the above might just be nonsense as I am no expert.

Anyone else have an idea?

[Richard Rathbone]

From the Skeptical Science article:

"...The transport of ocean heat to depths, and to the poles, will drastically slow down, ..."

That sounds like the Arctic melting will slow down as the rest of the world gets warmer, paradoxically. Is that correct?

No.

The area of their model which warms the fastest in the accelerated warming decades is the Arctic. See Figure 1b of the article the OP referred to.

This is a model study using a model whose predictive skill on arctic sea ice is bad. I wouldn't draw any conclusion about arctic sea ice from it.

[Bruce Steele]

Here is a link to the PDO index . The PDO numbers for May show the first positive monthly number since May 2010. 
http://jisao.washington.edu/pdo/PDO.latest

[BornFromTheVoid]

Here is a link to the PDO index . The PDO numbers for June show the first positive number since June 2010. 
http://jisao.washington.edu/pdo/PDO.latest

I think you're looking at May

[Gray-Wolf]

As you already know ,BFTV, I think that once this current PDO-ve phase is 'defined' ( after the phase is over) that NASA's (?) initial call for it behinning in 98' ( post Super nino) will be found correct?

As such , even though a 'short' phase we could well be emerging from the depths of the -ve phase?

I think the June figure will show even more positive than May and though we may see more -ve's on the plot that from now on we will edge toward PDO+ve?

The last papers I saw on PDO and AGW impacts they were quite plain that after the 1980's AGW warming was impacting the PDO? As such the 'cold periods will appear milder, the milder ones neutral and the positive ones ever more positive. I believe that this is what we have seen in this current PDO-ve and though it has had impact ( as PDO phases do) it has been moderated by our warming world.

The concern is just how fast the next 'warming phase' will appear to be when compared to the last PDO+ve impacted warming?

Will far Eastern 'global dimming' save us from the worst of this or will it dovetail into the Developing Nations introducing 'clean air technology'?

[Lynn Shwadchuck]

I appreciate the tight focus of this thread and the huge picture it paints. Really clear Skeptical Science article.

Gray-wolf's highlighting the scenario of the end of soot really tops it off. Sounds like we could be in for it!

[deep octopus]

Not to conflate the looming oceanic "climate shift" and Andrew Freedman's disturbing article on Climate Central on the waves of heat that are spanning from Alaska to the southwestern U.S., but this is still a thought to ponder. Another blocking event to document into our climate history. Another piece of evidence that, in my mind, conforms to the emerging picture of global warming.
http://www.climatecentral.org/news/heat-wave-to-threaten-worlds-hottest-temperature-record-16161

Emphasis mine.

The furnace-like heat is coming courtesy of a “stuck” weather pattern that is setting up across the U.S. and Canada. By early next week, the jet stream — a fast-moving river of air at airliner altitudes that is responsible for steering weather systems — will form the shape of a massive, slithering snake with what meteorologists refer to as a deep “ridge” across the Western states, and an equally deep trough seting [sic] up across the Central and Eastern states.

...

One study, published in the Proceedings of the American Academy of Sciences in 2012, found that the odds of extremely hot summers have significantly increased in tandem with global temperatures. Those odds, the study found, were about 1-in-300 during the 1951-1980 timeframe, but that had increased to nearly 1-in-10 by 1981-2010.

...

Extreme weather events, from floods to drought to heat waves, are often associated with blocked or “stuck” weather patterns. Such features were present during the deadly Russian heat wave of 2010, the European heat wave of 2003, and more recently during Hurricane Sandy, and the Alaskan heat wave and related flooding in Canada, for example.

I'll add to this list the blocking events that contributed to the March 2012 and June-July 2012 heat waves in the midwestern and eastern United States, the 2010 floods in Pakistan, and the 2011 drought in Texas.

To think of all the anomalous weather patterns and records that have occurred within a world that is 0.6 degrees C warmer than in the mid-20th Century gives me pause. The terms "stuck" and "blocking event" strike me as the most immediate form of climate disruption in our 0.6 C world, but one that is already becoming too stressful for the system. To imagine anything warmer than this occurring so quickly is just too daunting. How sensitive is our climate to 0.7 C warming? Or 0.8? Never mind the targeted 2 C.

[Lynn Shwadchuck]

Octopus, it's already so weird with these stuck growing season systems of either too much rain or too much dry heat. Hard to envision where it will all go if this thread's article in Skeptical Science (the study it talks about) is on the mark. Just overlay the maps from Freedman's column on the US Drought Monitor and think what's going to happen to a lot of crops this summer.

http://droughtmonitor.unl.edu/

[wili]

But if we are headed into an El Nino, doesn't that usually mean a wetter West for the US/North America?

I have no idea when the deep oceans may start regurgitating some of the vast stores of heat they have kindly been sequestering. Eventually we will have another El Nino that will leave '98 so far in the dust, even the denialosphere will forget it ever happened.

Meanwhile, the string of catastrophes world wide recently sure looks enough like an "Climate Shift":
Fires raging in the West and in Alaska...
Floods in Calgary, Germany, France, India...
Permafrost becoming permamelt...
Arctic sea ice becoming one big slushy...
Landcane in the Midwest...

If this is just the prelude to an actual "Looming Climate Shift," its about time to batten down the hatches.

[Richard Rathbone]

I have no idea when the deep oceans may start regurgitating some of the vast stores of heat they have kindly been sequestering.

Not until the surface cools back down again. 40,000-100,000 years or so. Soak enough in there now and it might stave off the Ice Age after next as it comes back out.

The transfer of heat into the the deep ocean is flip-flopping on a decadal timescale, but its not actually coming out on the next flip.

[JimD]

Richard,

Could you elaborate on the timespan of 40-100K years?  I was under the impression that the timespan for the return of the warmed water that dropped into the deep ocean was that of the THC at approx. 1600 years for a complete circuit.  What am I misunderstanding?

Also, I am under the impression that for the ocean to effect the surface atmospheric temperatures it is not required that the surface 'cool' for upwelling warm water to effect the surface air temperatures. Even if the upwelling deep ocean water is colder than the surface temperatures (which it is going to be most of the time) it can still result in surface warming.  The key factor being the temperature difference between the upwelling water and the surface.  With warmer upwelling water the rate of heat transfer, from the higher temperature  surface into the upwelling water, would be slower than it would be for colder upwelling water. The slowing rate of transfer would leave the surface warmer than would have been the result if the deep ocean water was not holding additional heat from AGW.  Is this correct?  If not, could you elaborate on this as well.

Thanks.

[deep octopus]

Regarding El Niño, newer research shows there is room for variation now with respect to precipitation, and this is based on the location of warm SSTs, forming phenomena called El Niño Modoki and La Niña Modoki.

The idea behind an El Niño Modoki is that western and central Pacific equatorial waters become warmer than average (the Nino 3.4 and Nino 4 regions), while Nino 1, 2, and 3 regions can stay cooler than average, thus creating different wind patterns that then change climate patterns more uniquely than a classic El Niño with a warm cone of water extending all the way to South America.
http://www.jamstec.go.jp/frcgc/research/d1/iod/e/elnmodoki/about_elnm.html

Per the specific question about what this means for the western US...

The ENSO Modoki has distinct teleconnections and affect many parts of the world. For example, the West Coast of United States of America is wet during El Nino but dry during El Nino Modoki (e.g. Weng et al. 2008). Recent studies show that teleconnections associated with ENSO Modoki influence the rainfall over India and South Africa (Ratnam et al. 2010; Ratnam et al. 2011).

So, there is some unfortunate potential for an El Niño without a wetter southwestern U.S. Such would truly be a "waste" of heat escaping the ocean.

Other links on this topic:
http://voices.washingtonpost.com/capitalweathergang/2009/07/el_nino_hurricanes_thdevil_may.html
http://www.aoml.noaa.gov/phod/docs/Revision2_JC.pdf

[Richard Rathbone]

Jim,

Milankovitch cycles http://en.wikipedia.org/wiki/Milankovitch_cycles are where I pulled 40-100 kyr from.

1600 years is the amount by which changes in the deep ocean lag behind those at the surface.

I assume a pre-industrial steady state, in which the temperature of surface and deep water isn't changing, although there is exchange of water between them. The surface then starts heating up, and due to the exchange of water between the layers, the deep water also heats up, but its response is delayed by that 1600 year lag. Hold the surface temperature constant at current levels, and eventually the deep water heats up to its new steady state value.

To bring the heat that is going down now back up again, the surface has to cool back down below the steady state temperature that corresponds to the amount the deep water has warmed so far, which due to the long lag time involved is still pretty close to the pre-industrial level. I assume that timescale is of the order of Ice Ages, though geo-engineering or a nuclear war could do it much faster.

You could have a warming effect by moving the currents to different locations, e.g. if upwelling shifted towards the poles, but that would be a consequence of changing the circulation rather than changing the temperature in the deep water. I've got no idea if that's happening at all or on what timescale it would operate.

Its not actually the THC taking much heat down yet. The polar ice needs to melt before polar water temperatures can increase much. Its circulations closer to the equator taking warmer water to intermediate depths rather than THC warming of the bottom water.

[Bruce Steele]

This article by Purkey is a nice synopsis.
http://www.livescience.com/28248-deep-ocean-warming.html
If the bottom water formation process slows then less very cold water is delivered to the bottom where it mixes with deep water thereby cooling and oxygenating the deep waters. In the southern oceans intermediate water formation processes are responsible for transporting the majority of anthropogenic Co2 into the oceans. Much heat is also absorbed in intermediate water processes. I would like to know how long it takes in the southern hemisphere for these intermediate waters to cycle from downwelling back to it's eventual upwelling.  The the northern hemisphere there is both intermediate and deep water formation in the north Atlantic. There is also intermediate water formation in the north Pacific in the Sea of Okhotsk. Using radio nucleotides and CFC's as tracers we can constrain the age from downwelling ( in the Sea of Okhotsk) to upwelling in the eastern Pacific at 35 to 50 years. So although it takes north Atlantic deep water over a thousand years to travel south enter the antarctic circumpolar current upwell in the eastern Pacific and return via the Gulf Stream other water masses cycle much faster, decades rather than centuries. So some of that heat ( and Co2)currently being absorbed by the oceans can potentially come back fairly soon depending on which water masses it is moving into.     

[JimD]

Bruce and Richard,

Thanks for the replies.  I am familiar with your link Bruce. 

Richard,  as your explanation was contrary to my understanding I have spent some time looking into this issue.  I am familiar with Milankovitch cycles and went and brushed up on them a bit more.  I also looked over Real Climate, Skeptical Science and Climate Progress regarding the heat in the deep ocean and ocean circulations.

Unless I have misunderstood what I have read you are incorrect on both counts.  Milankovitch cycles do not determine the rate of ocean circulation in any meaningful way to this discussion.

It seems pretty clear from what I have read that some of  the heat being transferred from the surface to the deep ocean is going to be brought back to the surface by the THC in about 1600 years.  The only possible change to this timeframe is a change in the THC where it is slowed or stopped (as has happened in the past).  The usual mechanism cited for that happening are large scale changes in salinity in the North Atlantic. 

To bring the heat that is going down now back up again, the surface has to cool back down below the steady state temperature that corresponds to the amount the deep water has warmed so far, which due to the long lag time involved is still pretty close to the pre-industrial level. I assume that timescale is of the order of Ice Ages, though geo-engineering or a nuclear war could do it much faster.

As long as there is upwelling water from the deep ocean, via the THC and the type of mechanisms detailed in the article, that water is going to have an immediate effect on surface temperatures.  This water is always going to be colder on average than the surface water or air  temperature.  But it can still cause surface temperatures to rise.  If the upwelling water temperature rises, due to a rise in downwelling heat transfer 1600 years previously (as is occurring today), it can cause surface temperatures to rise as there is a significant change in the rate of heat transfer from the surface to the water due to a smaller temperature difference between them.  Since the heat transfer slows this will let more heat (primarily being caused greenhouse gases) build up in the atmosphere and temperatures will rise as described in the article. 

As to your point that most of the heat transfer is not talking place via the THC, but rather by ocean currents as described in the article, it would seem to be indicated that the possible return time for that mechanism is even quicker than that indicated for the THC.

Here is a quote from Kevin Trenberth in reply to a question about how fast the heat can come back that ended up in the deep ocean.  I would guess he is pretty much an authority.  He indicated that strong El Nino's (and I presume mechanisms such as described in the article we are discussing) could bring the heat back very quickly.  This would indicate that the 1600 year THC period is on the long side of the time when it is coming back to us.

“It can come back quite fast,” he said. “The energy is not lost, and it can come back to haunt us, so to speak, in the future.”

Interesting discussion. 

[Richard Rathbone]

Jim

You misunderstand me. I invoke Milankovitch cycles for the timescale on which the surface cools, not for the timescale of ocean currents. Ocean currents are irrelevant to the timescale on which the direction of heat transfer changes.

Heating requires that the object being heated is colder than the object doing the heating.

The only reason water coming up now is colder than water going down, is that the surface has recently warmed. Its not always the case that water coming up is colder. Its only the case that water coming up is colder when heat is being transported down. On whatever timescale the surface eventually cools, the water coming back up will become hotter than the water going down, and thats when heat comes back out.

Simple box model.
Surface water at temperature Ts. Deep water at temperature Td. Flow between them w. Deep water mass Md, and residence time td=Md/w. Specific heat capacity of water C.

Heat transfer from surface to depth = wC(Ts-Td)

To get heat transfer from depth to surface requires Td>Ts

The main driver for changes in Td is this heat transfer.

wC(Ts-Td) = MdC dTd/dt

(Ts-Td)/td  = dTd/dt

For Td to increase requires Ts>Td and this can't happen until whatever is driving Ts drives Ts back down. (Ts-Td) will approach zero on the timescale of td but it can't go negative unless something else takes Ts down. You take your pick of driving mechanisms, I took Milankovitch, and whatever timescale that operates on is the timescale on which the heat transfer reverses.

This sort of box model is decent for long term trends.  The way I interpret the paper that inspired this thread in box model terms, is that the exchange rate, w, varies on a decadal timescale, and thus Ts increases at slower rates in the decades when w is high, and higher rates when w is low, despite a constant increase in radiative forcing.

If what is meant by heat coming back to bite us is that there are both El Ninos and La Ninas, or noise comes in above trend as well as below trend, then fair enough. However, heat coming back out of the deep ocean won't change the trend, it will never amplify the trend, all it will do is moderate the trend when something else causes it to reverse, just as it is currently moderating the upward trend.

[JimD]

Richard,

I will readily admit that I am some decades on from my thermo classes and the mathematics used to talk about them and, as such, I am not able to discuss this in the proper mathematical language.  Bear with me a bit.

I think I understand what you are saying and agree, but I think what I am trying to say is different.  I am not talking about heat flowing from cold to hot (which cannot happen of course) but rather the rate of heat transfer affecting temperature.   It seems to me that what we have is the following situation (in layman's terms).

Functionally we have a non-static heat situation and a multi-layer heat exchange going on where heat is coming into the system from one end (so to speak) and affecting the other layers which are contained and do not have the ability to transfer heat out of the system in any meaningful sense (this only happens at the top layer where the net is an increase).  So we know that the total heat in the system is going to constantly increase as long as we keep raising CO2 levels. As long as this situation in the top layer does not change we will never reach thermal equilibrium.

In very simple terms the top layer is the atmosphere, the middle is the surface (whether air, land or water) and the bottom are the various depths of the ocean we talk about.

The properties of our top layer are such that the heat is concentrated near the bottom of the layer where it is in contact with the surface (good thing or we would be bitching about being cold).  If we were to build an equation that described the transfer of heat into this model (which I am not capable of doing) it would have parts that describe the rate of transfer from the atmosphere to the surface and the rate of transfer from the surface to the water.    If we held this static this situation (and stopped heat coming into the air layer) your model would work.  But heat does come in and we know of various mechanisms that move the upper layer of the water to depths.  One is the THC and the other being that described in the article linked above.  So our equations have to reflect that the rate of transfer of heat into our colder lower layer varies by those mechanisms. 

If our layer of water is temp X and our lower air layer Y at all times your equations will have a steady answer.  But we have a varying temp X.  So the rate of transfer varies as X rises and falls because the difference between X and Y  affects that rate.  We also have a varying Y due to the constant heat being added to the system which also affects the rates of transfer.

As the article showed when the IPO/PDO changes and the down welling of the water to deeper layers stops then there is a corresponding increase in the surface temperatures.  The water is still colder than the lower atmosphere but the higher temp atmosphere gets warmer since the transfer of heat into the colder body slows and heat is still coming in the top (our air conditioner is not working efficiently so to speak).  This same situation arises when the circulation of the THC brings water warmed 1600 years ago back to the surface.  Once again, the heat transfer slows and forces heat to build up in the lower atmosphere.  Thus we do end up with rising temperatures in the lower atmosphere even though the water is colder than the air as we are not experiencing a transfer of heat from cold to hot but rather a slowing of the transfer from hot to cold and this means that the air will get warmer since there is still heat being added to the top of the layer.

So, what I am saying, is that, while energy does flow from hot to cold that statement does not adequately describe our complex system which is not in equilibrium.   If you stop taking as much heat to the bottom of the ocean it will get hotter at the surface and if the water coming up from below turns warmer it will also get hotter at the surface. 

[Richard Rathbone]

So, what I am saying, is that, while energy does flow from hot to cold that statement does not adequately describe our complex system which is not in equilibrium.   If you stop taking as much heat to the bottom of the ocean it will get hotter at the surface and if the water coming up from below turns warmer it will also get hotter at the surface.

Try this way of looking at it.

Say we have a background heating rate of 0.2 degrees per decade due to changing greenhouse gasses thats constant over time. The surface ocean has a lag of about a decade, so in the absence of heat transfer to the depths, it will take a few decades to get up to speed, and then match the 0.2 degrees per decade, while sitting 0.2 below what its equilibrium would be if the atmosphere stabilised.

Now we briefly open up circulation and take a pulse of water into the deep ocean. This has a cooling effect on the surface and a heating effect on the deep ocean. Say this completely replaces surface water with deep water. Thats taken as much heat from the surface as its possible to do.

We wait 50 years. This is long enough that the surface is now back to its 0.2 per decade while sitting 0.2 below equilibrium.

We briefly open up circulation to the deep again. There are two possibilities. We bring back the same water we sent down 50 years ago, or we bring out another slug of old, cold water. (Or some mixture of them).

If its the old water, the cooling is more intense than the last time, since in the intervening 50 years the surface has gone up by 1 degree, and the deep hasn't.

If its the 50 year old water coming back out, then its not cooling as much, but its still cooling, because the surface is 1 degree warmer than it was when that water was sent down.

I think you are just looking at one side of the picture. Cooling the surface by sending hot water down, causes the surface to heat faster in the interim, so that when the hot water comes back, it still results in cooling. You actually have to change the external driver to the surface temperature: greenhouse gases, Milankovitch insolation etc. before circulation can result in surface heating.

[JimD]

Richard,

That fits with my understanding exactly using different words.  Maybe it is my awkward description causing you problems and we have no disagreement at all.

But I have one more issue with your description.  From your post we have...

We wait 50 years. This is long enough that the surface is now back to its 0.2 per decade while sitting 0.2 below equilibrium.

We briefly open up circulation to the deep again. There are two possibilities. We bring back the same water we sent down 50 years ago, or we bring out another slug of old, cold water. (Or some mixture of them).

If its the old water, the cooling is more intense than the last time, since in the intervening 50 years the surface has gone up by 1 degree, and the deep hasn't.

If its the 50 year old water coming back out, then its not cooling as much, but its still cooling, because the surface is 1 degree warmer than it was when that water was sent down.

Regarding the last sentence.  This is where I am confused.  To me you are describing heat transfer rates in that quote. Going back to my somewhat awkward description of what I understand.  When you say "If its the 50 year old water coming back out, then its not cooling as much, but its still cooling..."  is that not the same as saying the 'rate' that heat is going into the water is not as great?  If it 'is' the same then we get to my point that if, during this period of upwelling warm water the heat transfer rate into the colder water is lower than the .2/decade (say .1/decade) that means that the heat build-up at the surface will exceed your .2/decade for a period of time (say .3 for example).  If this is correct then the surface temperatures will get warmer. 

Another way of saying "its not cooling as much, but it is still cooling" is that the heat transfer rate has slowed.  If so, then there has to be a build up of heat at the surface as the system is not in equilibrium any longer.  That results in a higher surface temperature.  The temperature of the water surface varies and that modulates the transfer rate as there is a constantly changing temperature differential between the water and the surface temperature.

It is like being in a house with a radiant heater and having it 0 degrees outside.  One has a steady rate of heat transfer to the outside through the wall.  The room stays the same temperature.  A mass of warmer air (say 5 degrees) moves in and surrounds the house.  Due to the smaller temperature differential between the air inside and outside the house the house will end up warmer since the heat transfer rate lessens and the heater is still putting out the same amount of energy.  Replace the outside air with the 0 degree air again and the house will eventually cool back to the original temperature.  While it would be incorrect to say that the 5 degree air "warmed" the room the effect of having the warmer outside air present "resulted" in a warmer house.   

Are we actually in agreement here?

[Richard Rathbone]

Not quite.

In your model of the house, you change the equilibrium temperature when you perturb it with the warmer air. The house warms because you change it from a state where it was at its equilibrium temperature to one where it was below its equilibrium temperature.

Changing the circulation rate in my model doesn't change the equilibrium temperature, it just changes the timescale over which that equilibrium is achieved.

The way I would draw the analogy to a house, is with the internal walls being the deep ocean, and the outside being the top of the atmosphere.  Putting CO2 into the atmosphere is like steadily upgrading your insulation. If you upgrade your insulation, but leave the heater at the same power, the temperature goes up, but the rate at which it goes up depends on how long it takes to heat up the internal walls as well as the rate you add insulation. Turn on a fan to blow air faster across the walls and the heat goes into them a bit faster, and the room heats up a bit slower in the short term and a bit faster in the long term, but you don't take heat back out of the wall when you stop blowing on it.

The deep ocean is interior to the surface, and that constrains the way heat can be transported more than you are allowing for.

[JimD]

Richard

I think I understand now.  Thanks for your patience!

Jim

[Richard Rathbone]

If you want something rather more complex than a box model on the dynamics of the climate response, try Hansen on the global energy imbalance and implications.

Its a controversial area because its tied in with aerosols and sensitivity estimates. The extreme values of sensitivity estimates come from different opinions about aerosol forcing and circulation with the deep ocean, and nobody has collected enough of the right data to narrow sensitivity to CO2 within the bounds of "dead men walking due to temperature increase we are already committed to", and "still a couple of generations of fossil fuel BAU before it is worth bothering over".

http://www.atmos-chem-phys.net/11/13421/2011/acp-11-13421-2011.html

Link is to abstract, but the paper is linked without paywall from the abstract.

[Gray-Wolf]

Maybe this needs a 'bump'?

With JMA the first to publish its 2014 data;

http://ds.data.jma.go.jp/tcc/tcc/products/gwp/temp/ann_wld.html

maybe we ought to revisit the subject of a climate shift? Back in July we were just starting to see the dominance of SST's in the NOAA climate series but now we see the impact of a years worth of such. Even in ENSO neutral we saw 2014 beat the temp it took a Super Nino to generate back in 98' so are we now seeing the naturals shifting toward states that augment the warming?

The last warming spurt both has full ice cover over the Arctic and reduced CO2 levels compared with today. It also didn't have 15yrs worth of warming stuffed into the top 700m of our oceans.

Looming climate shift?

[Laurent]

Humans threaten 4 of 9 key systems on Earth
http://www.futurity.org/earth-boundaries-climate-840662/

[Gray-Wolf]

The other thing I ought to have mentioned when talking of a 'resumption in higher warming rates' was the reduction in 'dimming' as China starts the task of cleaning up it's pollution issues?

I read a NASA press release a few years back that proposed that up to 50% of our potential warming was not occurring due to particulate pollution/sulphate pollution ( the flip side of the fossil fuel coin). Unlike the west when it decided it must act on pollution China has access to 'off the shelf' systems to scrub out their pollution issues ( we needed to develop them?) so the move toward 'clean air' should be far swifter there once motivated into action. Death rates due to upper respiratory issues ( compounded by high street level pollution rates) have become so acute  as to promote action by the govt. and so we must, by now, be entering a period of 'levelling off' in particulate/Sulphate pollution or even entering a 'drop off' in levels after ,what must have been, a short period of extreme rises ( as China expanded its energy usage?).

It takes up to seven years for sulphates to drop out of the air  but should we expect to also see increases in global temps due to the fall off in 'dimming'?

[jai mitchell]

Gray

The 7-year timeline for sulfate removal is related to stratospheric volcano eruptions and the removal of SO2 from the stratosphere.  The vast majority of the SO2 in the atmosphere is located in the lower and middle troposphere where it rains out on a very rapid timescale.  about 90% of the total emitted sulfates are removed within the first week and another 8% removed the second week.  Only a miniscule amount of Chinese smokestack emissions of SO2 lasts longer than 2 weeks.

You are correct, China has been very effective in reducing their SO2 emissions however they still have a very long way to go as they are still increasing their coal consumption at a rate of about 7% (more?) per year.  However, a significant economic slowdown and social pressures to reduce mortality due to air pollution will absolutely affect this.

When it does, and there is evidence that we have already been experiencing it since China started to aggressively address this issue in 2009, we will experience rapid increases in climate change effects.

[Laurent]

Smoke from distant fires could create more deadly tornadoes
http://news.sciencemag.org/earth/2015/02/smoke-distant-fires-could-create-more-deadly-tornadoes

[Laurent]

Mystery blob in the Pacific messes up US weather and ecosystems
http://www.newscientist.com/article/dn27362-mystery-blob-in-the-pacific-messes-up-us-weather-and-ecosystems.html?cmpid=RSS|NSNS|2012-GLOBAL|environment#.VTARhDf7vz8

Yet the patterns of warming seem to be different this time round, says oceanographer Mark Ohman of Scripps Institution of Oceanography in San Diego, California. "This is a phenomenon beyond the typical PDO-like oscillations we've seen for the recent decades," he adds. "I'm in a state of confusion."

[DavidR]

The PDO index has rocketed up to  greater than +2 over the last year and has been averaging above two for each of the past 4 months.

http://research.jisao.washington.edu/pdo/PDO.latest

The few times it has been this high for 4 consecutive months has almost always result in a record temperature year. If you  look at the detrended temperature data a low PDO causes a  below trend warming, except  for the past 15 years where it  has merely coincided with a alleged hiatus in warming.  The switch to a positive PDO will most likely  mean a switch to  rapidly  rising temperatures starting with a significant new high this year.

[AbruptSLR]

The linked Mashable article discusses 7 eye-opening facts about anthropogenic shifts/assaults   in/on Earth Systems:

http://mashable.com/2015/04/22/earth-day-facts/

[wili]

Again, the CC, deforestation, water, and food crises are all largely a result of extreme levels of meat eating, yet this is not mentioned once in the whole video. Why?

[sidd]

I posted this comment over at realclimate, but perhaps some here might want to discuss also.

I have been mulling over the rise in blocking events and persistent weather systems. While i tend to believe that Francis and Vavrus are on to something, there is another idea that might (or not) prove fruitful. When studying systems close to critical points there is a phenomenon called critical slowing down. In the classic Ising model this is seen in the relaxation times going to infinity as correlation lengths diverge. It occurs in many other systems as well. A naive measure of a relaxation time might come from the recovery after perturbation. I dont' see much evidence of this in things like response of surface temperature to volcanoes. Another approach might be  to define some kind of correlation length and see if it increases. (Teleconnections, anyone ?) I have thought of attempting the latter, from something like ERA, but i haven't yet. Also i imagine there are others who have thought this through better than me. Perhaps Tsonis has something.

The nature of any putative critical point could be a state with a single hemispherical atmospheric cell or a rearrangement of ocean circulation or arctic ice free state or more unpalatable things like a Canfield ocean.

sidd

[Shared Humanity]

I posted this comment over at realclimate, but perhaps some here might want to discuss also.

I have been mulling over the rise in blocking events and persistent weather systems. While i tend to believe that Francis and Vavrus are on to something, there is another idea that might (or not) prove fruitful. When studying systems close to critical points there is a phenomenon called critical slowing down. In the classic Ising model this is seen in the relaxation times going to infinity as correlation lengths diverge. It occurs in many other systems as well. A naive measure of a relaxation time might come from the recovery after perturbation. I dont' see much evidence of this in things like response of surface temperature to volcanoes. Another approach might be  to define some kind of correlation length and see if it increases. (Teleconnections, anyone ?) I have thought of attempting the latter, from something like ERA, but i haven't yet. Also i imagine there are others who have thought this through better than me. Perhaps Tsonis has something.

The nature of any putative critical point could be a state with a single hemispherical atmospheric cell or a rearrangement of ocean circulation or arctic ice free state or more unpalatable things like a Canfield ocean.

sidd

I posted a couple of years ago on this site (don't ask me where it is...I haven't a clue) some research that modeled the impact of a reduced temperature gradient between the pole and the equator on the Hadley, Ferrel  and Polar cells. The model predicted that, as the temperature gradient decreased as a result of the north pole warming more rapidly than the rest of the northern hemisphere, the first impact would be an expansion of the Hadley Cell at the expense of the Ferrel Cell. We are already seeing this occurring. The model than suggests that, at a certain point, the hemispheric cells would rapidly merge into a single hemispheric circulation. The models suggested a two cell circulation was highly unstable. This would cause an immediate transition into what they called a hothouse polar climate.

What was really interesting was that the research suggested that this single circulation cell in the northern hemisphere could and, likely has, coexisted with a three cell atmospheric cell in the  southern hemisphere for thousands of years as the Antarctic ice sheet persisted long after the Arctic Ocean had become ice free and therefore prevented a decline in the southern hemisphere temperature gradient.

[sidd]

Kidder and Worsley have some ideas, i have posted the reference b4, but i cannot immediately find it.

[Tor Bejnar]

...
I posted a couple of years ago on this site (don't ask me where it is...I haven't a clue) some research that modeled the impact of a reduced temperature gradient between the pole and the equator on the Hadley, Ferrel  and Polar cells. ...

Is this it?
http://forum.arctic-sea-ice.net/index.php?topic=499.0 
Re: The Cause of the Muted Melt of 2013
« Reply #26 on: August 12, 2013, 11:18:53 AM »

[mati]

here is the paper:
http://www.math.ualberta.ca/ami/CAMQ/pdf_files/vol_17/17_1/17_1e.pdf

and the slide deck:
http://slideonline.com/presentation/6848-hadley-cell-expansion-langford-pdf

[oren]

here is the paper:
http://www.math.ualberta.ca/ami/CAMQ/pdf_files/vol_17/17_1/17_1e.pdf

and the slide deck:
http://slideonline.com/presentation/6848-hadley-cell-expansion-langford-pdf

Thanks for the reference. I admit to having only read the slide deck, it's a really good (and disturbing) read.

[Shared Humanity]

here is the paper:
http://www.math.ualberta.ca/ami/CAMQ/pdf_files/vol_17/17_1/17_1e.pdf

and the slide deck:
http://slideonline.com/presentation/6848-hadley-cell-expansion-langford-pdf

That's it.

[mati]

the scary part is the bifurcation..
a sudden shift between the states... im not sure the exact temp difference where this exists....

[andy_t_roo]

the scary part is the bifurcation..
a sudden shift between the states... im not sure the exact temp difference where this exists....

I don't think anyone is, as it depends on the shape of the temp gradient, and that varies depending on land cover, as is indicated by they possibility of extended differing patterns for the north and south hemispheres.

[Subjectivist]

It all works the same whether you call it a bifurcated function or a tipping point.  Either way at some unknown threshold you switch from one mode of climate to the other mode.

A lecture I watched from a mathematician on the topic stated that one sign of a tipping point was wild swings in the tracked variables at the critical threshold, then everything calmed down afterwards in the new stable relationships.  The example used was a clear healthy pond with diverse ecosystems being turned into a turbid partially anoxic ecosystem that only supported a very small range of species adapted to those conditions.  In the example farm runoff of nitrogen fertilizers caused algal blooms that rotted quickly consuming most of the oxygen dissolved in the water.

For the switch from three cells to one cell it will be the same way, we will sooner or later dump enough CO2, NOx and CH4 into the atmosphere and suddenly we will go from what was to what is to be.

[colding]

It all works the same whether you call it a bifurcated function or a tipping point.  Either way at some unknown threshold you switch from one mode of climate to the other mode.

A lecture I watched from a mathematician on the topic stated that one sign of a tipping point was wild swings in the tracked variables at the critical threshold, then everything calmed down afterwards in the new stable relationships. 

<snip>

For the switch from three cells to one cell it will be the same way, we will sooner or later dump enough CO2, NOx and CH4 into the atmosphere and suddenly we will go from what was to what is to be.

The key quote is "wild swings in the tracked variables". What is the tracked variables in the case of the three cells? Latitudinal extent? Total air momentum? And do we have any good online resources tracking those variables for each cell?

Another interesting question: How are the amplitude and frequency of the swings, related to time line of an eventual coming shift?

[crandles]

MEI values over 2 happened in
82 & 83
87
92 (& 93 very close)
97 & 98

so regularly every 5 years then a long gap until 2015. Trouble with that is the lack of occurrences 1950 to 1982 (only 1972 got anywhere close), and 3 five year gaps isn't really enough to set a pattern. ENSO may well not be a place to look for a Northern Hemisphere departure from normal.

Mainly posted because I wanted to comment: if the swings you want to look for have that sort of noise, can you really distinguish something ominous from something that arises by chance from noise? Looking in hindsight seems likely to say 'if we had looked at such and such then we could have forecast this' but does this really mean that a major departure can be forecast in advance? Seems likely to result in a lot of false alarms to me.

[Subjectivist]

It all works the same whether you call it a bifurcated function or a tipping point.  Either way at some unknown threshold you switch from one mode of climate to the other mode.

A lecture I watched from a mathematician on the topic stated that one sign of a tipping point was wild swings in the tracked variables at the critical threshold, then everything calmed down afterwards in the new stable relationships. 

<snip>

For the switch from three cells to one cell it will be the same way, we will sooner or later dump enough CO2, NOx and CH4 into the atmosphere and suddenly we will go from what was to what is to be.

The key quote is "wild swings in the tracked variables". What is the tracked variables in the case of the three cells? Latitudinal extent? Total air momentum? And do we have any good online resources tracking those variables for each cell?

Another interesting question: How are the amplitude and frequency of the swings, related to time line of an eventual coming shift?

Well Dr. Francis is tracking the amplitude of the Rossby waves as well as the temperature differential on each side.  If I understood the ppt presentation linked to above correctly, so long as there is a large temperature differential between the Polar and Temperate cells we will maintain the three cell configuration.  However the smaller the temperature difference between the two sides of the cell boundary the more likely the boundary is to break up and merge into one uniform cell.  Some year or other we will end up with temperatures going into sync between the Temperate and Polar cell and then we will have the very unstable two cell system with Tropical on one side and Temperate on the other.  With the polar and Temperate merged together a great deal of heat from the Temperate zone would be dumped into the Polar region.  After months or years of that kind of heat transport the boundary between Temperate and Tropical zones breaks down and Viole' one cell takes over as the climate function. 

I think because of the amount of energy input needed you would probably see the Polar/Temperate cells merge in September of one year and then with the Temperate zone feeding energy up to the Polar zone all winter the next year you would start with very little ice in the Arctic Ocean allowing the sea to absorb sunlight rapidly due to low albedo.  From late May to late July the solar isolation in the Polar zone is higher than it is at the equator.  The only reason Polar summer is so cool is all the albedo effect rejecting the sunlight.  Take away the albedo and the pole will get very warm very quickly from the 24/7 high isolation situation.

Once the Arctic warms up that much be it one summer or several the temperature difference between the pole and equator will disappear and a single cell will form.  Once we collapse from three cells to one cell the climate will stabilize again, sub tropical all the way from Equator to the Arctic Circle and temperate from there to the pole.