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jai mitchell

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Quantifying underestimates of long-term upper-ocean warming
« on: October 06, 2014, 11:30:28 PM »
Paul J. Durack,   
 Peter J. Gleckler,   
 Felix W. Landerer   
 & Karl E. Taylor   


PAPER HERE


Nature Climate Change (2014) doi:10.1038/nclimate2389 Published online  05 October 2014

The global ocean stores more than 90% of the heat associated with observed greenhouse-gas-attributed global warming1, 2, 3, 4. Using satellite altimetry observations and a large suite of climate models, we conclude that observed estimates of 0–700 dbar global ocean warming since 1970 are likely biased low. This underestimation is attributed to poor sampling of the Southern Hemisphere, and limitations of the analysis methods that conservatively estimate temperature changes in data-sparse regions5, 6, 7. We find that the partitioning of northern and southern hemispheric simulated sea surface height changes are consistent with precise altimeter observations, whereas the hemispheric partitioning of simulated upper-ocean warming is inconsistent with observed in-situ-based ocean heat content estimates. Relying on the close correspondence between hemispheric-scale ocean heat content and steric changes, we adjust the poorly constrained Southern Hemisphere observed warming estimates so that hemispheric ratios are consistent with the broad range of modelled results. These adjustments yield large increases (2.2–7.1 × 10^22 J * 35 yr−1) to current global upper-ocean heat content change estimates, and have important implications for sea level, the planetary energy budget and climate sensitivity assessments.

Here are implications of the rates of future warming derived from the original Nucitelli et. al. 2013 data



full sized graphic here:  http://oi59.tinypic.com/209g0tk.jpg

The rate of heat accumulation is higher than previously understood.  The increased rate of accumulation indicates that future emissions projections (RCP 8.5 BAU) will lead to 30% higher heat accumulation by 2039 than thought previously.

Please note that this analysis does not include step-change albedo declines due to loss of Arctic Sea Ice in 10-30 years.  These should be considered lower bound estimates.
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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #1 on: October 06, 2014, 11:53:26 PM »
jai,

Thanks for opening a new thread on this topic, which begs such questions as: (a) what is the true Equilibrium Climate Sensitivity, ECS; (b) what is the Planetary Heat Budget; (c) when and how did/does heat get into both the upper, and lower, ocean; and (d) how quickly might slow response feedback mechanisms kick-in to contribute to temperature rise this century?

You mentioned previously that aerosols might contribute to some of the "global-warming hiatus", but this negative feedback from aerosols certainly cannot account for the heat going into the upper ocean over more than three decades that Durack et al (2014) have documented.  Clearly, this heat in the upper ocean indicates that the ECS is higher than the CMIP5 projections have assumed and that the excess heat has been making its way into the ocean via both PDO (see Tollefson (2014) and attached image) and AMO (see Mann et al 2014) related pathways.  However, from a Planetary Heat Budget point of view, we should not forget the heat going into the deep ocean as discussed by Llovel et al (2014).  Finally, I point-out that Lovejoy et al (2014) have proven that the "global-warming hiatus" must be natural variability and if so global warming will accelerate soon:

Jeff Tollefson, (2014), "Climate change: The case of the missing heat - Sixteen years into the mysterious ‘global-warming hiatus’, scientists are piecing together an explanation", Nature, 505, 276–278, doi:10.1038/505276a

http://www.nature.com/news/climate-change-the-case-of-the-missing-heat-1.14525
http://www.nature.com/polopoly_fs/1.14525!/menu/main/topColumns/topLeftColumn/pdf/505276a.pdf


Mann, M. E., B. A. Steinman, and S. K. Miller (2014), On forced temperature changes, internal variability, and the AMO, Geophys. Res. Lett., 41, 3211–3219, doi:10.1002/2014GL059233.

http://onlinelibrary.wiley.com/doi/10.1002/2014GL059233/abstract

Abstract: "We estimate the low-frequency internal variability of Northern Hemisphere (NH) mean temperature using observed temperature variations, which include both forced and internal variability components, and several alternative model simulations of the (natural + anthropogenic) forced component alone. We then generate an ensemble of alternative historical temperature histories based on the statistics of the estimated internal variability. Using this ensemble, we show, first, that recent NH mean temperatures fall within the range of expected multidecadal variability. Using the synthetic temperature histories, we also show that certain procedures used in past studies to estimate internal variability, and in particular, an internal multidecadal oscillation termed the “Atlantic Multidecadal Oscillation” or “AMO”, fail to isolate the true internal variability when it is a priori known. Such procedures yield an AMO signal with an inflated amplitude and biased phase, attributing some of the recent NH mean temperature rise to the AMO. The true AMO signal, instead, appears likely to have been in a cooling phase in recent decades, offsetting some of the anthropogenic warming. Claims of multidecadal “stadium wave” patterns of variation across multiple climate indices are also shown to likely be an artifact of this flawed procedure for isolating putative climate oscillations."

W. Llovel, J. K. Willis, F. W. Landerer & I. Fukumori, (2014), "Deep-ocean contribution to sea level and energy budget not detectable over the past decade", Nature Climate Change, doi:10.1038/nclimate2387


http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2387.html

Abstract: "As the dominant reservoir of heat uptake in the climate system, the world’s oceans provide a critical measure of global climate change. Here, we infer deep-ocean warming in the context of global sea-level rise and Earth’s energy budget between January 2005 and December 2013. Direct measurements of ocean warming above 2,000 m depth explain about 32% of the observed annual rate of global mean sea-level rise. Over the entire water column, independent estimates of ocean warming yield a contribution of 0.77 ± 0.28 mm yr−1 in sea-level rise and agree with the upper-ocean estimate to within the estimated uncertainties. Accounting for additional possible systematic uncertainties, the deep ocean (below 2,000 m) contributes −0.13 ± 0.72 mm yr−1 to global sea-level rise and −0.08 ± 0.43 W m−2 to Earth’s energy balance. The net warming of the ocean implies an energy imbalance for the Earth of 0.64 ± 0.44 W m−2 from 2005 to 2013."


Lovejoy, S. (2014), Return periods of global climate fluctuations and the pause, Geophys. Res. Lett., 41, 4704–4710, doi:10.1002/2014GL060478.

http://onlinelibrary.wiley.com/doi/10.1002/2014GL060478/abstract

Abstract: "An approach complementary to General Circulation Models (GCMs), using the anthropogenic CO2 radiative forcing as a linear surrogate for all anthropogenic forcings [Lovejoy, 2014], was recently developed for quantifying human impacts. Using preindustrial multiproxy series and scaling arguments, the probabilities of natural fluctuations at time lags up to 125 years were determined. The hypothesis that the industrial epoch warming was a giant natural fluctuation was rejected with 99.9% confidence. In this paper, this method is extended to the determination of event return times. Over the period 1880–2013, the largest 32 year event is expected to be 0.47 K, effectively explaining the postwar cooling (amplitude 0.42–0.47 K). Similarly, the “pause” since 1998 (0.28–0.37 K) has a return period of 20–50 years (not so unusual). It is nearly cancelled by the pre-pause warming event (1992–1998, return period 30–40 years); the pause is no more than natural variability."

Best,
ASLR
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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #2 on: October 07, 2014, 12:17:32 AM »
jai,

Also, do not forget that Cowtan & Way (2014) proved that the reported historical values for mean global temperature rise have been under reported (so this accounts for some of the missing heat), but also supports the case for a higher ECS value:

Cowtan, K. and Way, R. G., (2014), "Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends", Q.J.R. Meteorol. Soc., doi: 10.1002/qj.2297

Best,
ASLR
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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #3 on: October 07, 2014, 01:11:23 AM »
jai,

See also: McGregor et al (2014) illustrate the interaction between the Pacific, and Atlantic, Oceans [see: McGregor, S., A. Timmermann, M. F. Stuecker, M. H. England, M. Merrifield, F.-F. Jin and Y. Chikamoto, (2014), "Recent Walker circulation strengthening and Pacific cooling amplified by Atlantic warming", Nature Climate Change; doi:10.1038/nclimate2330].

Also, Praetorius & Mix (2014) provide paleo-evidence of the importance of the synchronization of the North Pacific, and the North Atlantic, Oceans on Arctic amplification: Summer K. Praetorius, Alan C. Mix, (2014), "Synchronization of North Pacific and Greenland climates preceded abrupt deglacial warming", Science 25 July 2014: Vol. 345 no. 6195 pp. 444-448 DOI: 10.1126/science.1252000

Also the importance of the Pacific Ocean is indicated in: Nicola Maher, Alexander Sen Gupta and Matthew H. England, (2014), "Drivers of decadal hiatus periods in the 20th and 21st Centuries", Geophysical Research Letters, DOI: 10.1002/2014GL060527.

Also, further to your point that your projection to 2039 is lower bound: Kim et al (2014) indicate that before 2040, CMIP5 models indicate that the amplitude of the ENSO phases will increase; indicating that when the El Nino events return for the next 25-years they are likely to be stronger than previously experienced leading to more abrupt climate change [see: Seon Tae Kim, Wenju Cai, Fei-Fei Jin, Agus Santoso, Lixin Wu, Eric Guilyardi & Soon-Il An, (2014), "Response of El Niño sea surface temperature variability to greenhouse warming", Nature Climate Change, doi:10.1038/nclimate2326].

Best,
ASLR
« Last Edit: October 07, 2014, 01:17:01 AM by AbruptSLR »
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jai mitchell

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #4 on: October 07, 2014, 01:38:22 AM »
ASLR,

I believe that the PDO is based on surface wind patterns.  The surface wind patterns are largely determined by regional temperature distributions.  These distributions are changed by aerosols.  I expect that we will soon find that aerosols are the driver for the PDO phase.

However, the heat accumulation is not based on the PDO, it is based on the total radiative forcing at the top of atmosphere.  Since more heat has accumulated than we previously thought, the amount of warming due to climate change is more.  This means that the ECS is higher than we previously thought and that the lower bounds are now raised, This will mean that the ECS is now most likely 3.3C to 5.1C.   

However, as I stated previously, there is an additional compounding effect from fast and slow feedback mechanisms that will produce a significantly higher warming.  I expect that we are already over the threshold of 5C warming if slow feedbacks are taken into account.
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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #5 on: October 07, 2014, 03:44:16 AM »
jai,

It certainly looks like we are headed for faster temperature rises than most people are willing to recognize.  It will be interesting to see whether the IPCC comes out with any new forcing scenarios to replace the RCP scenarios, and/or whether the IPCC decides to issue an AR6.  If they don't then policy maker can effectively ignore any high ECS values indicated by this research.
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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #6 on: October 07, 2014, 06:21:36 AM »
The linked article in Science AAAS points out that there is a lot of uncertainty in how much heat the deep ocean (especially below 6,000 m), that it is possible that the Antarctic Bottom Water, AABW, is carrying more heat into the ocean than models are currently assuming.  If so then ECS could be higher still than the upper ocean heat content data is indicating:

http://news.sciencemag.org/climate/2014/10/past-measurements-may-have-missed-massive-ocean-warming
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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #7 on: October 07, 2014, 06:59:02 PM »
As to one possible contributor to the recently discovered heat in the Southern Hemisphere upper ocean (and/or possible increasing ocean heat content below 6,000m), I point-out that Sherwood et al (2014) and Fasullo and Trenberth (2012) indicate that ECS is likely between 4 and 4.5 degrees C.  Furthermore, Shindell (2014) indicates that TCR is also likely proportionally higher than the AR5 assumes.

See:
Sherwood, S.C., Bony, S. and Dufresne, J.-L., (2014) "Spread in model climate sensitivity traced to atmospheric convective mixing", Nature; Volume: 505, pp 37–42, doi:10.1038/nature12829

http://www.nature.com/nature/journal/v505/n7481/full/nature12829.html

Fasullo, J.T. and Trenberth, K.E., (2012), "A Less Cloudy Future: The Role of Subtropical Subsidence in Climate Sensitivity", Science, vol. 338, pp. 792-794, 2012. http://dx.doi.org/10.1126/science.1227465.

http://www.sciencemag.org/content/338/6108/792

See also:

Shindell, D.T., (2014), "Inhomogeneous forcing and transient climate sensitivity", Nature Climate Change, Vol.: 4, pp: 274–277, doi:10.1038/nclimate2136.

http://www.nature.com/nclimate/journal/v4/n4/full/nclimate2136.html

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jai mitchell

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #8 on: October 08, 2014, 02:57:50 AM »
I have run the spreadsheets.

This adjustment to Nuccitelli et. al. 2013 indicates a top of atmosphere adjustment from a current .7 w/m^2 upward to a possible .9w/m^2.

This means that we will cross the top of atmosphere warming threshold of 1 watt per square meter between 2019 and 2027  instead of 2033.  In other words, we just lost between 6 and 14 years in our timeline to achieve meaningful mitigation in an attempt to thwart catastrophic and irreversible climate change.  Also, more warming will occur more rapidly with fewer total emissions.



full image here:  http://oi58.tinypic.com/2ex60ip.jpg


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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #9 on: October 08, 2014, 01:36:06 PM »
As a follow on to jai's post quantifying the effect of the recently identified Southern Hemisphere upper ocean heat content, I would like to remind readers that this quantification is a lower bound solution (as jai cites in his first post), and the following information/link provide by Bruce Steele in the Antarctic folder shows that a $21 million dollar grant has recently been approved to provide more deep monitoring ARGO floats that could very well identify more ocean heat content that still has not been recognized:

Re: Selected Forcing Factor for Abrupt SLR from the Collapse of the WAIS
« Reply #302 on: September 12, 2014, 06:34:21 PM »
A  co-ordinated 21 million dollar study to deploy a large field of Argo floats has been funded and although the link below doesn't specify the deep dive abilities of the new Argo floats I am sure they will be deployed. We may get a much better picture of the current state of the Southern Oceans  carbon cycle with the new pH sensors that are also part of this study. What is going on with Antarctic Bottom Water formation? A clearer picture is soon to arrive .

https://scripps.ucsd.edu/news/southern-oceans-role-climate-regulation-ocean-health-goal-21-million-federal-grant

Furthermore, in his first post jai pointed-out that his lower bound projections do not include positive feedback mechanisms such as the potential rapid decrease in albedo due to the probable early reduction in Arctic Sea Ice extent; & I also note that some new CMIP5 runs indicate that in the next 25 to 30 years the North Pacific and the North Atlantic are projected to come into sync. with continued warming which will still further increase Arctic amplification.
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AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #10 on: October 09, 2014, 10:31:08 PM »
Further to the portion of my Reply #3 about synchroneity of the North Pacific and the North Atlantic; the linked reference indicates that the Earth System Sensitivity, ESS, may be bigger than previously thought, due to this synchroneity, and perhaps the extra heat discovery in the Southern Hemispheric upper ocean could help drive the earth to this state in the next twenty to thirty years:

Summer K. Praetorius, Alan C. Mix, (2014), "Synchronization of North Pacific and Greenland climates preceded abrupt deglacial warming", Science 25 July 2014: Vol. 345 no. 6195 pp. 444-448 DOI: 10.1126/science.1252000

http://www.sciencemag.org/content/345/6195/444
http://www.sciencemag.org/content/suppl/2014/07/23/345.6195.444.DC1/Praetorius.SM.pdf
http://www.sciencemag.org/content/345/6195/444.figures-only

Abstract: "Some proposed mechanisms for transmission of major climate change events between the North Pacific and North Atlantic predict opposing patterns of variations; others suggest synchronization. Resolving this conflict has implications for regulation of poleward heat transport and global climate change. New multidecadal-resolution foraminiferal oxygen isotope records from the Gulf of Alaska (GOA) reveal sudden shifts between intervals of synchroneity and asynchroneity with the North Greenland Ice Core Project (NGRIP) δ18O record over the past 18,000 years. Synchronization of these regions occurred 15,500 to 11,000 years ago, just prior to and throughout the most abrupt climate transitions of the last 20,000 years, suggesting that dynamic coupling of North Pacific and North Atlantic climates may lead to critical transitions in Earth’s climate system."

See also:

Brigham-Grette, Julie; Melles, Martin; Minyuk, Pavel, et al., (2013) "Millennial scale change from Lake El’gygytgyn, NE Russia: Did we step or leap out of the Warm Pliocene into the Pleistocene?"

http://instaar.colorado.edu/meetings/AW2013/abstract_details.php?abstract_id=78



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Michael Hauber

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #11 on: October 17, 2014, 11:32:31 AM »
A greater amount of heat content increase in the southern ocean does not immediately imply a higher climate sensitivity.  In particular it does not guarantee that the total heat budget of the earth needs to increase.  The total heat budget of the earth must match the top of atmosphere radiative imbalance.  So perhaps our estimate of the TOA radiative imbalance is wrong and needs to be increased.  Or perhaps the heat budget elsewhere is wrong and needs to be changed to balance the books.  In particular the aerosol component is highly uncertain and when church et al attempted to work out the heat budget they calculated the aerosol component as the residual when other facts were taken into account. 

So what if the aerosol component is wrong?  In that case an increased amount for the ocean heat flux would imply a smaller residual  (see figure 3 of church et al) and a smaller value for aerosol cooling.  This would then imply a lower value for climate sensitivity, and not a higher value.
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TeaPotty

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #12 on: October 17, 2014, 04:31:33 PM »
Michael Hauber, you continue to strengthen the impression that you are indeed trolling this forum. It seems you are a rabid anti-alarmist, despite your obviously low level of knowledge, and you consistently argue for that "side" often in lack of any logical argument or understanding of current research. I am sure I am not the only one who cringes whenever you post, because you are not here to learn, you are here to police and lecture your ideals.

AbruptSLR

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #13 on: October 17, 2014, 04:32:25 PM »
A greater amount of heat content increase in the southern ocean does not immediately imply a higher climate sensitivity.  In particular it does not guarantee that the total heat budget of the earth needs to increase.  The total heat budget of the earth must match the top of atmosphere radiative imbalance.  So perhaps our estimate of the TOA radiative imbalance is wrong and needs to be increased.  Or perhaps the heat budget elsewhere is wrong and needs to be changed to balance the books.  In particular the aerosol component is highly uncertain and when church et al attempted to work out the heat budget they calculated the aerosol component as the residual when other facts were taken into account. 

So what if the aerosol component is wrong?  In that case an increased amount for the ocean heat flux would imply a smaller residual  (see figure 3 of church et al) and a smaller value for aerosol cooling.  This would then imply a lower value for climate sensitivity, and not a higher value.

Michael,

First, work such as Shindell (2014), shows that ECS cannot be less than 3.0 degrees C and meet the observed modern climate record.  Therefore, your implication that uncertainty could imply lower values of ECS (lower than 3 degrees C) is nonsense.  At best your argument implies that ECS might be near 3 degrees C.

Shindell, D.T., (2014), "Inhomogeneous forcing and transient climate sensitivity", Nature Climate Change, Vol.: 4, pp: 274–277, doi:10.1038/nclimate2136

Second, you talk like it somehow makes sense to wait to act until we learn more – that learning more will some how dramatically clarify our options; however, society needs to recognize that we don't (and will never) know everything, but that taking meaningful action now to fight climate change will pay off, with less risk and also with more jobs (meaning that building a sustainable economy will result in job growth).

Best,
ASLR
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Steven

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #14 on: October 17, 2014, 08:00:05 PM »
...work such as Shindell (2014), shows that ECS cannot be less than 3.0 degrees C and meet the observed modern climate record.

I had a look at the Shindell 2014 paper you are referring to (pdf), but was unable to see how this paper implies that the Equilibrium Climate Sensitivity "cannot be less than 3°C".

Note that the abstract of the Shindell paper says the following about the Transient Climate Response:

Quote
I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (<1.3°C) is very unlikely.

This refers to the value 1.3°C for the transient climate response, which corresponds to a value of about 2 to 2.5°C or so for the equilibrium climate sensititivity, I think.  So the paper suggests that the sensitivity is very unlikely to be less than that.

For comparison, here is Figure 10.20(a) of the latest IPCC WG1 report, which shows the "very likely" range for the Transient Climate Response:


« Last Edit: October 17, 2014, 08:15:03 PM by Steven »

jai mitchell

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #15 on: October 17, 2014, 10:52:52 PM »



This needs to be more fully looked at.

1.  The adjustments are above the CMIP MMM error bars.

2.  The adjustments come from the southern hemisphere only, the northern hemisphere follows with the CMIP MMM.

3.  The error found in the 0-700meter southern hemisphere increases the total global heat accumulation (as compared by Nuccitelli et. al 2012) by (roughly) 9-30%.

Implications for TOA heat flux

1.  Total heat flux imbalance is now adjusted upwards from .7 to .9 watts per meter squared.

2.  Since the entirety of this adjustment occurred in the southern hemisphere, (but not the northern) indicates  that there is a fundamental flaw in the basic model of understanding.

3.  The basic model of understanding appears to be severely underestimating northern hemisphere aerosol effects.   

4. The basic model also appears to be extremely underestimating GHG radiative forcing effects, (measurement error in SH + aerosol adjustment error in NH)

5.  This analysis pushes the AR5 results to the very edge of the 2-sigma error range for these two forcing mechanisms.

 

Implications:

1.  ECS is now likely between 3C and 5.5C with an increased "most likely" value of 4C for a 2X CO2.

2.  Future land-only temperatures will increase under given emissions pathways at a much higher rate than previously modeled as TOA energy imbalance increases 20% more rapidly.

3.  Carbon cycle and permafrost degradation will occur more rapidly and more intensely than previously considered.

4.  This does explain a bit why the modeled arctic sea ice projections were deviating so strongly from observations.  The relatively aerosol-free arctic is experiencing a much higher downward longwave flux than has been modeled.

----------------

In addition, a higher GHG forcing and stronger aerosol effect would reveal anthropogenic impacts on 1910-1975 warming trends as well as lend increased weight to Ruddiman et. al (2011)  http://www.whoi.edu/pclift/Ruddiman.pdf
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #16 on: October 17, 2014, 10:57:36 PM »
I am becoming less and less interested in the exact value of climate sensitivity as defined by the rise in global average surface temp in transient or equilibrium response to doubled atmospheric CO2.  The bigger and closer devils are the in local variations of temperature and precipitation, ecosystem simplification, the ocean, and the ice, or more precisely, the coming lack thereof.

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #17 on: October 18, 2014, 01:34:22 AM »
Michael Hauber, you continue to strengthen the impression that you are indeed trolling this forum. It seems you are a rabid anti-alarmist, despite your obviously low level of knowledge, and you consistently argue for that "side" often in lack of any logical argument or understanding of current research. I am sure I am not the only one who cringes whenever you post, because you are not here to learn, you are here to police and lecture your ideals.

Call me what you like.  It won't make my arguments any more or less valid.
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Michael Hauber

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #18 on: October 18, 2014, 01:39:25 AM »
A greater amount of heat content increase in the southern ocean does not immediately imply a higher climate sensitivity.  In particular it does not guarantee that the total heat budget of the earth needs to increase.  The total heat budget of the earth must match the top of atmosphere radiative imbalance.  So perhaps our estimate of the TOA radiative imbalance is wrong and needs to be increased.  Or perhaps the heat budget elsewhere is wrong and needs to be changed to balance the books.  In particular the aerosol component is highly uncertain and when church et al attempted to work out the heat budget they calculated the aerosol component as the residual when other facts were taken into account. 

So what if the aerosol component is wrong?  In that case an increased amount for the ocean heat flux would imply a smaller residual  (see figure 3 of church et al) and a smaller value for aerosol cooling.  This would then imply a lower value for climate sensitivity, and not a higher value.

Michael,

First, work such as Shindell (2014), shows that ECS cannot be less than 3.0 degrees C and meet the observed modern climate record.  Therefore, your implication that uncertainty could imply lower values of ECS (lower than 3 degrees C) is nonsense.  At best your argument implies that ECS might be near 3 degrees C.

Shindell, D.T., (2014), "Inhomogeneous forcing and transient climate sensitivity", Nature Climate Change, Vol.: 4, pp: 274–277, doi:10.1038/nclimate2136

Second, you talk like it somehow makes sense to wait to act until we learn more – that learning more will some how dramatically clarify our options; however, society needs to recognize that we don't (and will never) know everything, but that taking meaningful action now to fight climate change will pay off, with less risk and also with more jobs (meaning that building a sustainable economy will result in job growth).

Best,
ASLR

Urgent action is required.  However I disagree with stating uncertain possibilities as if they are certain.  Perhaps this result requires a higher sensitivity.  Perhaps there is a serious flaw with the logic I have presented.  But perhaps not?
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #19 on: October 18, 2014, 01:40:27 AM »
...work such as Shindell (2014), shows that ECS cannot be less than 3.0 degrees C and meet the observed modern climate record.

I had a look at the Shindell 2014 paper you are referring to (pdf), but was unable to see how this paper implies that the Equilibrium Climate Sensitivity "cannot be less than 3°C".

Note that the abstract of the Shindell paper says the following about the Transient Climate Response:

Quote
I conclude that the lowest end of the range of transient climate response to CO2 in present models and assessments (<1.3°C) is very unlikely.

This refers to the value 1.3°C for the transient climate response, which corresponds to a value of about 2 to 2.5°C or so for the equilibrium climate sensititivity, I think.  So the paper suggests that the sensitivity is very unlikely to be less than that.

For comparison, here is Figure 10.20(a) of the latest IPCC WG1 report, which shows the "very likely" range for the Transient Climate Response:



Steven,
Perhaps I was a bit too definite in my prior statement about a clear lower bound for ECS; however, the following extract from the linked source shows that Shindell (2014) calculations show that the TCR is estimated to be lying within the range of 1.3 to 3.2 centigrade degrees, with a median value of 1.7 centigrade degrees.  Also, the attached image by Shindell shows that the red TCR probability distribution function is skewed to the right, thus emphasizing higher values, the caption for the figure is given at the bottom of this post:

http://www.cccep.ac.uk/newsAndMedia/Releases/2014/Importance-of-new-study-on-the-sensitivity-of-the-Earths-climate.aspx

Extract: "Dr Shindell was a co-author on a paper by Alexander Otto and others, published in the journal ‘Nature Geoscience’ last year, which suggested that the value of the transient climate response lies between 0.9 and 2.0 centigrade degrees, with a median value of 1.3 centigrade degrees. However, Dr Shindell’s new paper shows that if a correction is made to the assumptions about aerosols and ozone, the transient climate response would be estimated to be higher, lying within the range of 1.3 to 3.2 centigrade degrees, with a median value of 1.7 centigrade degrees."

Also see:
http://www.realclimate.org/index.php/archives/2014/04/shindell-on-constraining-the-transient-climate-response/

&

David A. Stainforth, (2014), "Climate projection: Testing climate assumptions", Nature Climate Change4,248–249doi:10.1038/nclimate2172

Figure caption: "Figure shows representative probability distribution functions for TCR using the numbers from Shindell (2014) in a Monte Carlo calculation (Gaussian for Fghg and dTobs, lognormal fits for the skewed distributions for Faerosol+ozone+LU and E). The green line is if you assume exactly no difference between the effects of aerosols and GHGs; Red is if you estimate that difference using climate models; Dashed red is the small difference made by using a different start date (1850 instead of 1750)."
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #20 on: October 18, 2014, 01:52:59 PM »
As a follow-on to my last post (Reply #19):

The following linked Skeptical Science article (and associated extract) states that when Kummer & Dessler (2014) (see reference at bottom of this post) calculate that the best estimate of ECS is 3oC, they conservatively assume that climate is 33% more sensitive to changes in aerosols and ozone than greenhouse gases; however, Shindell (2014) showed that climate is more sensitive to changes in aerosols and ozone than greenhouse gases perhaps by as much as 50%.  Therefore, perhaps Kummer & Dessler are under estimating the best value of ECS by as much as 50%/33%, or by a factor of about 1.5.  If so then based on Shindell (2014) the best estimate of ECS may perhaps be 4.5 oC instead of 3oC.

https://www.skepticalscience.com/sense-and-climate-sensitivity-kummer-dessler-2014.html

Extract: "In short, Shindell showed that according to models, the climate is significantly more sensitive to changes in aerosols and ozone than greenhouse gases, perhaps by as much as 50%. Kummer & Dessler showed that if the climate is 33% more sensitive to changes in aerosols and ozone, then the 'instrumental' estimates are right in line with those derived from historical climate changes and global climate models, with a best estimate of 3°C warming in response to a doubling of atmospheric CO2."

J.R. Kummer and A.E. Dessler, (2014), "The impact of forcing efficacy on the equilibrium climate sensitivity", Geophysical Research Letters, DOI: 10.1002/2014GL06004

http://onlinelibrary.wiley.com/doi/10.1002/2014GL060046/abstract

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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #21 on: October 18, 2014, 02:03:03 PM »
To me the following linked reference, and extract, from a June 11 2014 Skeptical Science article indicates that: (a) The close match of the CESM1-CAM5 Large Ensemble Community Project, LE, mean global surface warming rates (in degrees C per decade) to the observed NOAA record indicates that the 4.1 degrees C ECS value used by the LE ensemble is a very likely value, and that ESS values this century could exceed this value; and (b) finds that"… a relatively unchanged planetary imbalance during the recent hiatus period is entirely consistent with analogous periods in LE simulations."

http://www.skepticalscience.com/challenges-constraining-climate-sensitivity.html

Caption: "Fig. 2: The range of decadal trends in global mean surface temperature from the CESM1-CAM5 Large Ensemble Community Project (LE, black and grey lines, 18) along with an observed estimate based on the NOAA-NCDC Merged Land and Ocean Surface Temperature dataset. Also shown are the mean (circle) and range (lines) of simulated planetary imbalance (right axis) from 2000 through 2010 for the 10 members of the LE with greatest cooling (blue) and warming (red)."
 
Extract: "The NCAR CESM1-CAM5 Large Ensemble Community Project provides a unique framework for understanding the role of internal variability in obscuring forced changes. It currently consists of 28 ensemble members in simulations of the historical record (1920-2005) and future projections (2006-2080) based on RCP8.5 forcing.
At 4.1 C, the ECS of the CESM1-CAM5 is higher than for most GCMs. Nonetheless, decadal trends from the model track quite closely with those derived from NOAA-NCDC observations (red line), with the model mean decadal trend (thick black line) skirting above and below observed trends about evenly since 1920. In several instances, decadal trends in observations have been at or beyond the LE ensemble range including intervals of exceptional observed warming (1945, 1960, 1980) and cooling (1948, 2009). The extent to which these frequent departures from the LE reflect errors in observations, insufficient ensemble size, or biases in model internal variability remains unknown. Nonetheless, there is no clear evidence of the model sensitivity being systematically biased high. Also noteworthy is the fact that the LE suggests that due to forcing, as indicated by the ensemble mean, certain decades including the 2000s are predisposed to a reduced rate of surface warming.

The LE also allows for the evaluation of subsets of ensemble members, such as in Fig 2, where the planetary imbalances for the 10 ensemble members with the greatest global surface warming (red) and cooling (blue) trends from 2000-2010 are compared. It is found that no significant difference exists between the two distributions and the mean imbalance for the cooling members is actually greater than for the warming members. Thus the finding of a relatively unchanged planetary imbalance during the recent hiatus period is entirely consistent with analogous periods in LE simulations. While the LE does suggest that recent trends have been exceptional, this is also suggested by the instrumental record itself, which includes exceptional El Niño (1997-98) and La Niña events (2010-2012) at the bounds of the recent hiatus."
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #22 on: November 11, 2014, 01:08:09 AM »
Migrations from Conservative Scientist Thread

FYI the Durack et. al analysis has pushed ECS up from 4.5 to between 4.75 and 5.5

The 1.1 lowball estimate is based on paleoclimate analysis that is limited to ice age periods (they threw out the interstadial inputs because their models blew up). 

It is clear that current top of atmosphere energy imbalances make the 1.1 limit so completely untenable that its very presence within the body of the report is the most damnable indication of falsehoods and suppression of real risk messaging. 

There is no FREAKING way that it can possibly be 1.1 with .6C already happened, .7C locked in at current emissions and another .7C projected as soon as we reach ice free arctic summers. 

I have yet to see a real honest scientific argument that can honestly state 1.1 has any credibility.  When a scientist buys into that argument without proof, I consider it to be akin to a tobacco industry executive testifying before the U.S. congress that he "doesn't believe that nicotine is addictive."
« Last Edit: November 12, 2014, 06:31:13 PM by jai mitchell »
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #23 on: November 11, 2014, 01:08:50 AM »
FYI the Durack et. al analysis has pushed ECS up from 4.5 to between 4.75 and 5.5

The 1.1 lowball estimate is based on paleoclimate analysis that is limited to ice age periods (they threw out the interstadial inputs because their models blew up). 

It is clear that current top of atmosphere energy imbalances make the 1.1 limit so completely untenable that its very presence within the body of the report is the most damnable indication of falsehoods and suppression of real risk messaging. 

There is no FREAKING way that it can possibly be 1.1 with .6C already happened, .7C locked in at current emissions and another .7C projected as soon as we reach ice free arctic summers. 

I have yet to see a real honest scientific argument that can honestly state 1.1 has any credibility.  When a scientist buys into that argument without proof, I consider it to be akin to a tobacco industry executive testifying before the U.S. congress that he "doesn't believe that nicotine is addictive."

I've already explained why Durack et al is more likely to mean a lower climate sensitivity not higher.  No one has explained the flaw in my reasoning, but simply resorted to name calling.

The lowball estimate for ECS according to IPCC is 1.5, not 1.1.  It is not justified by paleoclimate analysis only, but is also supported by several observational studies.  Currently the Co2 equivelant in the atmosphere is something like 480ppm, which is over 70% of a doubling.  Add 0.6 to the 0.7 locked in and we are at 1.3.  70% of a doubling at 1.5 ECS would be at about 1 degree.  That 0.3 degree difference could easily be due to a combination of some of the warming to date being caused by something other than Co2, or the 0.7 estimate of locked in warming being in error.  As for the 0.7 increase due to an ice free Arctic - I call nonsense.

When you make such basic errors, and then proceed to accuse scientists of fraud, I find that  extraordinarily offensive.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #24 on: November 11, 2014, 01:11:34 AM »
FYI the Durack et. al analysis has pushed ECS up from 4.5 to between 4.75 and 5.5

The 1.1 lowball estimate is based on paleoclimate analysis that is limited to ice age periods (they threw out the interstadial inputs because their models blew up). 

It is clear that current top of atmosphere energy imbalances make the 1.1 limit so completely untenable that its very presence within the body of the report is the most damnable indication of falsehoods and suppression of real risk messaging. 

There is no FREAKING way that it can possibly be 1.1 with .6C already happened, .7C locked in at current emissions and another .7C projected as soon as we reach ice free arctic summers. 

I have yet to see a real honest scientific argument that can honestly state 1.1 has any credibility.  When a scientist buys into that argument without proof, I consider it to be akin to a tobacco industry executive testifying before the U.S. congress that he "doesn't believe that nicotine is addictive."

I've already explained why Durack et al is more likely to mean a lower climate sensitivity not higher.  No one has explained the flaw in my reasoning, but simply resorted to name calling.

The lowball estimate for ECS according to IPCC is 1.5, not 1.1.  It is not justified by paleoclimate analysis only, but is also supported by several observational studies.  Currently the Co2 equivelant in the atmosphere is something like 480ppm, which is over 70% of a doubling.  Add 0.6 to the 0.7 locked in and we are at 1.3.  70% of a doubling at 1.5 ECS would be at about 1 degree.  That 0.3 degree difference could easily be due to a combination of some of the warming to date being caused by something other than Co2, or the 0.7 estimate of locked in warming being in error.  As for the 0.7 increase due to an ice free Arctic - I call nonsense.

When you make such basic errors, and then proceed to accuse scientists of fraud, I find that  extraordinarily offensive.

I am sorry, I must have missed that argument, re Durack et. al, care to provide a link/thread?

The 1.3C of locked in warming is based on purely catching up to current top of atmospheric radiative forcing.  It doesn't include feedbacks and also neglects to include current aerosol forcing which has a strong (temporary) cooling effect and reduces the 480 CO2 equivalent value significantly.  I thought this was clear in my post.  The locked in value comes directly from a lecture by James Hansen.  If we consider these values from my post and current CO2 equivalent is about 400ppmv then we have ECS = (.7+.6+.7)/(400ppmv/560ppmv)  = 2.8C  So James Hansen was being conservative in his estimation.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #25 on: November 11, 2014, 01:12:15 AM »
Michael,

Ahh I see, ok I found the "explanation" you wrote on why Durack et. al means lower ECS.

here it is:

A greater amount of heat content increase in the southern ocean does not immediately imply a higher climate sensitivity.  In particular it does not guarantee that the total heat budget of the earth needs to increase.  The total heat budget of the earth must match the top of atmosphere radiative imbalance.  So perhaps our estimate of the TOA radiative imbalance is wrong and needs to be increased.  Or perhaps the heat budget elsewhere is wrong and needs to be changed to balance the books.  In particular the aerosol component is highly uncertain and when church et al attempted to work out the heat budget they calculated the aerosol component as the residual when other facts were taken into account. 

So what if the aerosol component is wrong?  In that case an increased amount for the ocean heat flux would imply a smaller residual  (see figure 3 of church et al) and a smaller value for aerosol cooling.  This would then imply a lower value for climate sensitivity, and not a higher value.

I glossed over it because it was not an argument but rather conjecture, based on a fundamental misunderstanding of Durack et. al and the physics involved. 

This is why I say that:

Indeed the earth will continue to warm until the Top of Atmosphere (TOA) radiative imbalance reaches zero.  The estimate of TOA is derived from an accurate accounting of historic energy accumulations in the earth's biosphere.  Since Durack et. al. found that we have underestimated the earth's historic warming by between 10 and 30%, the TOA must be increased accordingly.  Having a higher TOA for a given set of emissions then implies a higher ECS.  Indeed, Gavin Schmidt did a rough calculation and tweeted that it increased the potential maximum ECS by about 9%

However, Durack et. al found that the models correctly tracked ocean heat accumulation in the Northern Hemisphere, the revision to heat accumulations were from the southern oceans only.  This then implies that the impact of the anthropogenic aerosols are UNDERESTIMATED (potentially severely) since the impact of aerosols are felt overwhelmingly in the northern hemisphere. 

It should be noted here that the uncertainty for aerosol emissions have a very fat tail, especially secondary cloud effects.  It also implies then that jet contrails may also be a negative forcing, not a positive one as currently modeled (if the aerosol effect is much more negative than currently expressed in the models).

If a significant portion of the southern ocean underestimate of heat accumulation is due to the higher aerosol and contrail cloud effect negative radiative forcing, then the ECS will be revised higher, potentially much higher (by 30% or more).
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #26 on: November 11, 2014, 01:12:58 AM »

I glossed over it because it was not an argument but rather conjecture, based on a fundamental misunderstanding of Durack et. al and the physics involved. 

This is why I say that:

Indeed the earth will continue to warm until the Top of Atmosphere (TOA) radiative imbalance reaches zero.  The estimate of TOA is derived from an accurate accounting of historic energy accumulations in the earth's biosphere.  Since Durack et. al. found that we have underestimated the earth's historic warming by between 10 and 30%, the TOA must be increased accordingly.  Having a higher TOA for a given set of emissions then implies a higher ECS.  Indeed, Gavin Schmidt did a rough calculation and tweeted that it increased the potential maximum ECS by about 9%

However, Durack et. al found that the models correctly tracked ocean heat accumulation in the Northern Hemisphere, the revision to heat accumulations were from the southern oceans only.  This then implies that the impact of the anthropogenic aerosols are UNDERESTIMATED (potentially severely) since the impact of aerosols are felt overwhelmingly in the northern hemisphere. 

It should be noted here that the uncertainty for aerosol emissions have a very fat tail, especially secondary cloud effects.  It also implies then that jet contrails may also be a negative forcing, not a positive one as currently modeled (if the aerosol effect is much more negative than currently expressed in the models).

If a significant portion of the southern ocean underestimate of heat accumulation is due to the higher aerosol and contrail cloud effect negative radiative forcing, then the ECS will be revised higher, potentially much higher (by 30% or more).

The top of atmosphere balance is not found by adding all the components.  It is found by direct measurement by satellite.  eg here

In contrast the aerosol component of the energy balance is uncertain, and Church et al calculates it by taking the measured top of atmosphere imbalance and subtracting the other components.

Therefore Durack is most likely to imply a reduced aerosol cooling component.  I did state a lower equilibrium sensitivity but some more thinking I'm not sure about that part.  I think the total picture would be less current aerosol cooling means less current co2 warming, but more heat captured by the ocean would mean more lag on the co2 warming so that equilibrium sensitivity would remain the same, but we'd get there slower.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #27 on: November 11, 2014, 01:13:40 AM »
Mike,

from your linked paper

Quote
TOA are also well documented, although inherently less accurate with an uncertainty of ±4 Wm–2 on the net TOA flux that mostly stems from calibration errors on measurements of the outgoing fluxes12,15. This uncertainty is almost an order of magnitude larger than the imbalance of 0.58 ±0.4 Wm–2 inferred from Ocean Heat Content information13,14.

in other words, the calibration error from the satellite readings is higher than the expected TOA value. 

In church et. al. they use calculated forcings taken from other authors to determine total forcings and then subtract the heat inventory to get the residual.

This is explained here:
Quote
the time-integrated cooling due to tropospheric aerosol (and any unidentified forcings) is inferred as the time-integral of the other forcings (well-mixed greenhouse gas, solar and volcanic) minus the sum of the heat storage and the time-integrated climate radiative response, and amounts to 800 × 1021 J (Figure 3a and Table 2) [716 for 1972–2008, 815 for 1961–2008].

None of the sources used satellites to determine the forcing, indeed portions of the calculation occurred before the satellite era.


You did not mention that the extra heat accumulation occurred solely in the southern hemisphere. . .

I get what you are saying about more heat means less aerosols (aerosols and cloud-effects being the highest uncertainty)

However, there are other uncertainties such as Total GHG radiative forcing effects.  If this value is much higher and the aerosol and cloud-effect components are more negative then this would produce accurate models in the northern hemisphere but higher than modeled heat accumulations in the southern.  In this environment a given GHG abundance produces a much higher forcing value, therefore this pushes the most likely ECS value much higher (by upwards of 30%).

Is this what we are seeing today?
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #28 on: November 11, 2014, 01:14:15 AM »
Mike,

from your linked paper

Quote
TOA are also well documented, although inherently less accurate with an uncertainty of ±4 Wm–2 on the net TOA flux that mostly stems from calibration errors on measurements of the outgoing fluxes12,15. This uncertainty is almost an order of magnitude larger than the imbalance of 0.58 ±0.4 Wm–2 inferred from Ocean Heat Content information13,14.

in other words, the calibration error from the satellite readings is higher than the expected TOA value. 

Sorry.  I find the Church et al paper to be tricky and confusing - it seems to be written for people who have a lot of background knowledge about the whole heat budget issue.  So I tried to find a paper that gave a simpler answer without noticing the size of the uncertainty.


In church et. al. they use calculated forcings taken from other authors to determine total forcings and then subtract the heat inventory to get the residual.

This is explained here:
Quote
the time-integrated cooling due to tropospheric aerosol (and any unidentified forcings) is inferred as the time-integral of the other forcings (well-mixed greenhouse gas, solar and volcanic) minus the sum of the heat storage and the time-integrated climate radiative response, and amounts to 800 × 1021 J (Figure 3a and Table 2) [716 for 1972–2008, 815 for 1961–2008].

None of the sources used satellites to determine the forcing, indeed portions of the calculation occurred before the satellite era.

Not quite:  From the paper:

Quote
The rate of storage of heat by the climate system equals the net heat flux into the climate system N = F − λΔT, where F is the radiative forcing, ΔT is the global averaged temperature change and the climate feedback parameter λ is assumed constant over this period (but see discussion below). This parameter is inversely related to climate sensitivity to a doubling of carbon dioxide, ΔTeq = 3.7 W m−2/λ. Murphy et al. [2009] used a regression of N − F, with N determined from satellite radiative flux data from the ERBE and CERES missions, against the global averaged temperature change ΔT to make an observational estimate of the climate feedback parameter.

That is the net heat flux into the climate system is determine as a combination of satellite measurement, forcing data and temperature change history.  It is not determined by adding up the heat accumulation in each component as your argument maintains.

You did not mention that the extra heat accumulation occurred solely in the southern hemisphere. . .

I get what you are saying about more heat means less aerosols (aerosols and cloud-effects being the highest uncertainty)

However, there are other uncertainties such as Total GHG radiative forcing effects.  If this value is much higher and the aerosol and cloud-effect components are more negative then this would produce accurate models in the northern hemisphere but higher than modeled heat accumulations in the southern.  In this environment a given GHG abundance produces a much higher forcing value, therefore this pushes the most likely ECS value much higher (by upwards of 30%).

Is this what we are seeing today?

That is not relevant as ocean currents and wind etc can move heat around - the heat does not have to be stored in the same hemisphere as it originally is collected.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #29 on: November 11, 2014, 01:14:48 AM »
Quote
ocean currents and wind etc can move heat around - the heat does not have to be stored in the same hemisphere as it originally is collected

Yes, but how fast can this heat be substantially moved around between the two hemispheres?
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #30 on: November 11, 2014, 01:15:37 AM »
Mike,

Quote
That is not relevant as ocean currents and wind etc can move heat around - the heat does not have to be stored in the same hemisphere as it originally is collected.

This is a good example of the PR strategy of distortion and denial.  We are talking about ocean heat.  Since the ocean currents stay within the same hemisphere, and the DURACK et. al. paper showed that the heat accumulation occurred within the southern hemisphere then the energy stayed in the southern hemisphere.

this is the second time that you have passed over this point, using distortion and then feigning ignorance to assert some kind of message.

"I am not a scientist but. . ."

Even when you are shown that the TOA cannot be determined by satellites (as you asserted) you quote a single phrase that states an entirely different paper (which I read) that used some satellite input in their shortwave incidence radiation calculation, but since EVEN THE TITLE of their paper shows they used this input to develop a MODEL and did not use DIRECT MEASUREMENTS (as you said), your entire argument is deception and obfuscation.

Again, I am sure you will simply claim ignorance. . .

An observationally based energy balance for the Earth since 1950
Murphy et. al. (2009)
http://onlinelibrary.wiley.com/doi/10.1029/2009JD012105/pdf
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #31 on: November 11, 2014, 01:16:30 AM »
It's good to see that a lot of deceptive strategies are at play here, that suggests importance of the subject. Trying desperately to complicate simple things, as well as willfully making the dialog hyper–technical (so as to throw off any potential lurkers and make them feel it's boring or complicated) are but two such strategies. I'm sure we can pinpoint more in the new year summary.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #32 on: November 11, 2014, 01:17:03 AM »
Mike,

Quote
That is not relevant as ocean currents and wind etc can move heat around - the heat does not have to be stored in the same hemisphere as it originally is collected.

This is a good example of the PR strategy of distortion and denial.  We are talking about ocean heat.  Since the ocean currents stay within the same hemisphere, and the DURACK et. al. paper showed that the heat accumulation occurred within the southern hemisphere then the energy stayed in the southern hemisphere.


Rubbish


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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #33 on: November 11, 2014, 01:17:52 AM »
Quote
Scientists estimate that the trip from the North Atlantic to the deep water upwelling sites in the Pacific takes about 1,600 years.

http://scied.ucar.edu/ocean-move-thermohaline-circulation

Quote
Relying on the close correspondence between hemispheric-scale ocean heat content and steric changes, we adjust the poorly constrained Southern Hemisphere observed warming estimates so that hemispheric ratios are consistent with the broad range of modelled results. These adjustments yield large increases (2.2–7.1 × 1022 J 35 yr−1) to current global upper-ocean heat content change estimates, and have important implications for sea level, the planetary energy budget and climate sensitivity assessments.

http://www.nature.com/nclimate/journal/v4/n11/full/nclimate2389.html

Again, you appear to be arguing with disinformation.  Please speak to the fact that the paper had to adjust up the southern hemisphere heat content but not the northern hemisphere heat content.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #34 on: November 11, 2014, 01:18:24 AM »
It is not how long it takes the water to get from one end of the TCH to the other that matters - but rather the amount of heat flux that crosses the equator.

And by this argument then the additional heat in the southern hemisphere can't be Co2 either, because that is global.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #35 on: November 11, 2014, 01:18:59 AM »
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It is not how long it takes the water to get from one end of the TCH to the other that matters - but rather the amount of heat flux that crosses the equator.

If so, how much heat crosses the equator by ocean currents each year, on average?
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #36 on: November 11, 2014, 01:19:40 AM »
Quote
It is not how long it takes the water to get from one end of the TCH to the other that matters - but rather the amount of heat flux that crosses the equator.

If so, how much heat crosses the equator by ocean currents each year, on average?

I don't know.  Its your theory that not enough heat can move between the hemispheres to account for the difference, so I'm not working out the numbers for you.

When you go look them up, don't forget to include the effect of the mass movement of air involved in the monsoon flowing from roughly 20N to 20S each year, and the regular movement of water from the subtropicals to the equator where it mixes and then is discharged to the subtropics again as part of the ENSO cycle.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #37 on: November 11, 2014, 01:20:12 AM »
Quote
And by this argument then the additional heat in the southern hemisphere can't be Co2 either, because that is global.

notice how you have now diverted the discussion away from Ocean heat content and top of atmosphere energy imbalances, satellite records and the final goal, effects of Durack et. al on ECS.

this circular reasoning is characteristic of disinformation campaigns.

The increase in GLOBAL CO2 forcing is balanced by INCREASED negative forcing of first and second order (cloud) aerosol feedbacks, the vast majority of which affect the northern hemisphere, as I state previously.

and yet, you continue to disregard the issue regarding north/south energy deposition adjustments by Durack et. al.

say it with me, increased CO2 and Methane contributions to positive forcing, balanced by Increased first and second order negative aerosol forcings, primarily acting on the northern hemisphere leading much higher likelihood of HIGHER ECS values. . .
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #38 on: November 11, 2014, 01:20:41 AM »
Quote
I don't know.  Its your theory that not enough heat can move between the hemispheres to account for the difference, so I'm not working out the numbers for you.

"I am not a scientist but. . ."

I will tell you right now, the amount of heat transport from the interhemispheric mass movement of the MOC is undetectable over the annual or even decadal periods we are discussing.

It takes approximately 800 years for the water from the equator to reach the atlantic subduction zone, that's about 7 miles per year.

Quote
When you go look them up, don't forget to include the effect of the mass movement of air involved in the monsoon flowing from roughly 20N to 20S

Again, we are discussing the observed amount of ocean heat content gain in the southern oceans.  but you still deny discussing this issue, instead deflecting with even more red herrings and diversions and outright lies (i.e. MOC as a heat transport between hemispheres).

I understand your tactics and observe your disinformation.  I see now that you are indeed a disinformer intent on polluting the forum.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #39 on: November 11, 2014, 01:21:10 AM »
"how much heat crosses the equator by ocean currents each year, on average?"
See

http://oceanworld.tamu.edu/resources/ocng_textbook/chapter05/chapter05_07.htm

Say 2 Petawatt at 20N

There are some old papers by Emig and Bydyko (and many new ones also)

sidd
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #40 on: November 11, 2014, 01:21:38 AM »
"how much heat crosses the equator by ocean currents each year, on average?"
See

http://oceanworld.tamu.edu/resources/ocng_textbook/chapter05/chapter05_07.htm

Say 2 Petawatt at 20N

There are some old papers by Emig and Bydyko (and many new ones also)

sidd

Sidd,

We are talking about heat transport from the southern hemisphere to the northern hemisphere, not from the equatorial regions to the polar regions.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #41 on: November 11, 2014, 01:22:19 AM »
Quote
I don't know.  Its your theory that not enough heat can move between the hemispheres to account for the difference, so I'm not working out the numbers for you.

Michael,
You make a statement about ocean heat flux, and I have my doubts about the accuracy of that statement. So I ask you a logical question, to find out what you base your statement on. You answer you don't know. So you just suppose your statement could be true, but it could be wrong as well.

Apparently you have no interest in trying to find out if it's right or wrong. So indeed you only seem to argue one way, questioning the argument by others that Durack et al seems to imply higher ECS. It just doesn't make sense, except for trying to downplay the risks of global warming for one reason or another.

Also on the remaining carbon budget you just don't respond to the arguments and references given. You seem smart enough, but not really willing to use your intelligence reasonably. Maybe I'm wrong, but that's how it seems to me for now.

Or can you at least tell us what you think the remaining carbon budget is for having a good chance to stay below 2 or 1.5 degrees? And can you at least admit that since you don't know the magnitude of the ocean heat flux you refer to that Durack et al may imply a higher ECS?
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #42 on: November 11, 2014, 01:22:54 AM »
"how much heat crosses the equator by ocean currents each year, on average?"
See

http://oceanworld.tamu.edu/resources/ocng_textbook/chapter05/chapter05_07.htm

Say 2 Petawatt at 20N

There are some old papers by Emig and Bydyko (and many new ones also)

sidd

Sidd,

We are talking about heat transport from the southern hemisphere to the northern hemisphere, not from the equatorial regions to the polar regions.

on the page i posted, 0.5 Petawatt at equator

sidd
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #43 on: November 11, 2014, 01:23:23 AM »
more to the point it's about stocks and flows. Off the top of my head, so check my numbers, Durack(2014) estimates around 0.1 to 0.5 * 1e22 J/yr OHC underestimate in SHemis.
Half a petawatt across the equator is about 3 times the upper number

sidd
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #44 on: November 11, 2014, 01:23:56 AM »
Sidd,

there is no value on the page you posted that I can see, however it is simply a red herring distraction from the topic of discussion (ECS implications by Durack et. al).  I am sure that if you multiply the flow rate of the MOC by the specific heat capacity and the delta temperature you will come up with a very small number since the flowrate is so slow.

-------
doh, or you may find it is about 1 petawatt of northerly transport.

http://cdiac.ornl.gov/oceans/glodap/glodap_pdfs/Thermohaline.web.pdf

the durack et.al estimates are from 1970 to 2004 (34 years)  and estimate an increase in OHC for the southern hemisphere of 2.2 to 7.1 * 10^22 joules

so the amount of heat transport is significant and significantly larger than the adjustments (by 2 orders of magnitude).  In this point I was incorrect in my estimation of cross equitorial heat transport.

however, as I said before, the values of heat accumulation in Durack et. al. stand independent (or rather, regardless of) heat transport across the equator.

The issue isn't where this additional heat will end up, but rather, what caused the additional heat in the southern half of the planet (vs. the northern half).
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #45 on: November 11, 2014, 01:24:34 AM »
Sidd,

there is no value on the page you posted that I can see, however it is simply a red herring distraction from the topic of discussion (ECS implications by Durack et. al).  I am sure that if you multiply the flow rate of the MOC by the specific heat capacity and the delta temperature you will come up with a very small number since the flowrate is so slow.

So any time anyone comes up for clear evidence that you are wrong, you just label it as a distraction?

Original argument - you need to add up all the heat content components to get the total heat budget, therefore increasing one component increases the total
rebutal - heat budget is measured independently of adding the components
new argument - but the extra heat is in the SH, (I assume the point of that is that there are more aerosols in the NH so it can't be aerosols?)
rebutal - but heat mixes between the hemispheres by stuff like currents
new argument - there are no currents between NH and SH
rebutal - yes there is - the THC
new argument - but it takes 1600 years to get from north atlantic to south atlantic
rebutal - doesn't matter it is the amount of heat that crosses the equator
new argument - it doesn't transfer enough heat,
rebutal (thanks sid)- the net heat flow of all currents flowing from North to South hemisphere is more than 3 times the upper estimate of the heat increase in the southerhn hemisphere
new argument - you are throwing out red herrings.

Lastly I leave a thought - The increase in OHC for the southern hemisphere heat content is justified because a) it matches the CMIP 5 models better - in particular to achieve the balance of heat between SH and NH predicted by these models, b) it matches sea surface height better.
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #46 on: November 11, 2014, 01:25:22 AM »
I can play that game too mike

1. Durack et. al. indicates a potentially higher ECS
rebuttal no it doesn't because it doesn't indicate an increase in the earths' heat budget

2. Yes it does because the paper in Durack et. al. precisely stated an increase in the earth's heat budget in the southern oceans, as opposed to the northern ones
rebuttal no It doesn't because the earths heat budget is found by satellites, not by adding components

3. Satelites have too high of measurement uncertainty to determine TOA so heat budget estimates rely on summations of individual components, in fact all three papers you referenced said as much. However, none of this matters because the issue is that the additional heat is added to the southern ocean which indicates an issue with aerosol forcing estimates.
rebuttal: the heat added to the southern ocean cannot be CO2 because CO2 is a global effect

4.  can we please talk about impacts to ECS?  the impact to the southern ocean is (potentially) derived by a significant underestimation of aerosol forcing values which would lead to higher ECS.
rebuttal: heat in the southern oceans is not relevant because it doesn't remain there and can be moved around.

5.  The entire point of Durack et. al. is to show a 35 year increase adjustment to the total ocean heat content in the southern hemisphere.  Why do you keep bringing up statements that have no impact on the argument regarding ECS?

and now, finally,

rebuttal:  Durack et. al. added heat to the southern ocean because it fits the CMIP5 model and sea surface analysis

which leaves then:

6.  The adjustment to southern hemisphere OHC in Durack et. al. is significantly higher than the 2 sigma high error estimation of the CMIP5 Multi model mean (in fact it is higher than 3 sigma!)

and, YES! the methodology that they used relied on sea surface elevations! very good!

But, may I ask once again, why is it that this doesn't impact ECS?



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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #47 on: November 11, 2014, 01:26:20 AM »
Quote
3. Satelites have too high of measurement uncertainty to determine TOA so heat budget estimates rely on summations of individual components, in fact all three papers you referenced said as much.

No the Church paper specifically says that the heat budget total is calculated as a combination of satellite observations of radiation, temperature history and modelling.  None of the papers that I or anyone else has referenced state that the total heat budget is calculated by adding up the individual components.  As I've said several times now.


5.  The entire point of Durack et. al. is to show a 35 year increase adjustment to the total ocean heat content in the southern hemisphere.  Why do you keep bringing up statements that have no impact on the argument regarding ECS?

and now, finally,

rebuttal:  Durack et. al. added heat to the southern ocean because it fits the CMIP5 model and sea surface analysis

Well obviously if the rate of heat accumulation in the southern ocean is faster then the final temperature that the globe as a whole reaches at equilibrium must higher?  I mean why would any logic be needed to explain that??
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #48 on: November 11, 2014, 01:27:19 AM »
I try to calculate how many nuclear bombs per second is that 7.1 10y22 Joule.
Wikipedia says little boy was : 67 TJ   http://en.wikipedia.org/wiki/Little_Boy
Per year : 7.1 10y22 / 35 = 2,028571429×10²¹ Joule
Per day : /360 = 5,634920635×10¹⁸ Joule
Per hour : /24 = 2,347883598×10¹⁷ Joule
Per secondes : /3600 = 6,521898883×10¹³ Joule
Per nuclear bombe : /67.10y12 = 0,973417744 Nuclear Bombs/seconde

That's not 4 nuclear bombs per seconds used on the Neven blog, skeptical and other... is there underestimation somewhere ?

Quote
the durack et.al estimates are from 1970 to 2004 (34 years)  and estimate an increase in OHC for the southern hemisphere of 2.2 to 7.1 * 10^22 joules
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Re: Quantifying underestimates of long-term upper-ocean warming
« Reply #49 on: November 11, 2014, 01:27:50 AM »
Would that be the average over 35 years for the Southern Hemisphere?

The four bombs per second would be over the last decade or so for the whole planet, I guess.
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