An OHC update

I thought I might briefly mention the recent paper on Quantifying underestimates of long-term upper-ocean warming, by Durack et al. (2014). The relevant result is stated in the abstract, which says

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, ….. 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.

The key figure is below which shows how this analysis influences the different estimates for the upper 700m Ocean Heat Content

Figure 5 from Durack et al. (2014)

Figure 5 from Durack et al. (2014)


One has to be careful of single study syndrome, but this is clearly relevant given the recent paper by Lewis & Curry (2014). They estimated the Equilibrium Climate Sensitivity (ECS – but really an Effective Sensitivity) using

ECS = \frac{F_{2xCO2} \Delta T}{\Delta F - \Delta Q} ,

and one of my main criticisms was that they seemed to minimise \Delta Q (the change in system heat uptake rate) by choosing a rate during the base period that seemed higher than other estimates, and a rate during the final period that was about as low as as it could reasonably be. This new paper would suggest that \Delta Q could be significantly higher than the value used by Lewis & Curry (2014), and would consequently increase their ECS estimate. I haven’t actually done the calculation, but a tweet from Gavin Schmidt suggests that this adjustment would reduce the difference between the Lewis & Curry range and the IPCC range (I’ve updated this post since, as you can see below, the preliminary calculation suggested a closer agreement than the later calculation gave).

This adjustment doesn’t influence the Transient Climate Response (TCR) since that does not depend on the change in system heat uptake rate, being determined using

TCR = \frac{F_{2xCO2} \Delta T}{\Delta F}

However, adjustments to the HadCRUT4 temperature record, as suggested by Cowtan & Way (2013) would also increase the TCR estimate.

The problem that I see with all of this is that it seems as though one can make assumptions and choose datasets that produce low estimates, and make assumptions and choose datasets that give higher estimates. Actually doing a single calculation that would convince most seems quite difficult. What might be useful would be a thorough study that consider all the reasonable assumptions and choices of datasets. One might then be able to produce a more reasonable range and best estimate, based on some combination of the results using these different possible assumptions and data choices. I will add, though, that if it is known that some dataset has an issue (for example, that HadCRUT4 has a samplying bias) then this should really be acknowledged and considered – something that, in my opinion, Lewis & Curry (2014) didn’t do particularly well.

There’s also the issue that these simple estimates cannot consider non-linearities in the feedbacks, inhomogeneities in the forcings, or slow feedbacks. Consequently, I’ve always felt that they’re quite useful as a basic check, but can’t really be regarded are more robust or reliable than other methods. That they seem to give ranges that are similar to the IPCC ranges would seem to be more a confirmation of the IPCC estimates, than a reason to argue against them.

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48 Responses to An OHC update

  1. Pingback: Scommesse – Ocasapiens - Blog - Repubblica.it

  2. Raff says:

    Anders it is much too early to be dissecting this paper. I suggesting writing a comment for GRL in about 2020 and then revisiting it in excruciating detail around about 2030. That is what an good “auditor” would do 😉

  3. Raff,
    Eventually I’ll work out how to do this 🙂

  4. Andrew Dodds says:

    Raff –

    You forget petulantly demanding every last piece of raw and processed data, computer programs used, videos of researchers using those programs with relevant newspapers for dating in the picture, original water samples, and a gratis fleet of satellites to replicate the research. With even the slightest delay in providing any of these to be commented on with lashings of insinuation of fraud.

    Note that you don’t have to do anything with the data once you get it.

    It’s interesting that a technical post like this attracts far fewer comments..

    For what it’s worth, I do wonder about even the possibility of refining sensitivity estimates further. If sensitivity itself is temperature dependent, and the system we are measuring is already out of equilibrium, and also subject to things like deforestation/afforestation that themselves will be independently affecting the climate on ECS timeframes.. (i.e. the movement of a forest/desert boundary is not just dependent on the temperature, as it would be in paleo-based estimates).

    Need more planets to experiment on.

  5. If I’d wanted to more comments I should probably have insisted that, in light of this new information, Lewis & Curry should retract their paper and do some kind of never-ending penance.

  6. BBD says:

    Andrew Dodds

    Give someone time to insert a fake controversy or similar thread hijack 🙂 That said, there was gratifyingly little nonsense on the similarly technical D-O thread.

  7. Note to ATTP: I have almost no formal training in science or engineering but the math in general is fine, so please feel free to keep the math-based posts up, and this includes any reply to my questions below that I freely admit are based on my lack of specific knowledge in this area.

    What’s the upshot of all this on the “missing heat” question? If this result is combined with the result by Tung and Chen, then would that mean that all the “missing heat” has been found?

    I ask this because there are already articles exploding all over the Internet about that NASA study concluding that there’s relatively very little heat in the oceans below 2000 meters. The deniers are already going crazy on this one.

    The Livescience article on the Tung and Chen paper said, “Tung and Chen noticed that the North Atlantic’s heat content (a measure of stored energy) shifted in 1999, about when the hiatus began. The ocean started absorbing heat at depths below 984 feet (300 m). (The South Atlantic Ocean also took up some heat.) These regions stored more heat energy than the rest of the world’s oceans combined, even the enormous Pacific Ocean, the researchers’ temperature data show.”

    Would the distribution of whatever heat in the oceans below 2000 meters matter with respect to the measurements NASA took? That is, compare the supposition that whatever heat is there is distributed very broadly and evenly with the supposition that its distribution reflects what is said in the above article on the Tung and Chen result, that whatever heat is there is distributed such that the vast majority of it is contained in one and only one area. Would it matter which is assumed? Would each assumption yield the same result?

    (I’m sure that lots of people would like to know the answers to these two sets of questions, especially with respect to knowing what to say to our denier neighbors, especially the ones already going crazy on that NASA result! And please give some citations and links as part of an answer.)

  8. verytallguy says:

    KeefeandAmanda

    you could start here

    http://www.skepticalscience.com/warming-oceans-rising-sea-level-energy-imbalance-consistent.html

    Beware of terminology. As I understand it, the NASA result is for heat *below* 2000m. This is referred to as “abyssal”. The SKS post uses “deep” to mean 700-2000m.

    I think all the NASA post is saying is that there is no evidence to suggest the abyssal ocean (200m+) is adding to the heat imbalance.

    My understanding is that measurements of “deep” ocean (700-2000m) already provide sufficient heat to reach consistency with the energy imbalance we expect; this was not the case with earlier measurements only considering 0-700m. The study referenced by ATTP in the post obviously adds further to this in the 0-700m range. (I think I’m right in saying that early versions of ARGO only went down to 700m?)

    Others with more expertise – please correct the mistakes I’ve doubtless made here!

  9. I think what VTG says is roughly right. As it is, we have a planetary energy imbalance of 0.6 – 0.7 Wm-2, so we’re accumulating energy at a rate that is consistent with what we’d expect. The surface is warming more slowly than was expected, which is certainly a surprise, but internal variability can influence trends on decadal timescales at level of a few tenths of a degree per decade. They can also influence the planetary energy imbalance at the level of a few tenths of a Wm-2. So, I don’t think that the abyssal ocean (> 2000m) not appearing to be warming is particularly significant.

  10. @KeefeAndAmanda:

    Tung and Chen is pure speculation. They believe Atlantic multidecadal ocean heat variability is internally forced (causing planetary changes of deep ocean heat uptake via Atlantic Meridional Overturning Circulation), but they don’t provide any actual evidence for that other than the results of their EOF interpretation exercise. The proposed salinity mechanism is all but new and they completely fail to rule out effects related to anthropogenic (tropospheric) and volcanic (stratospheric) aerosols. Discounting a very strong external forcing signal just doesn’t add substance to their argument. Personally, I tend to think that all they’ve discovered is a delayed response to external forcing (of course strongly superimposed by natural variability, which makes it not only hard to attribute, but a thousand times easier to misinterpret). Getting too excited about their paper(s) might lead to surprises in the not so distant future. Same applies to me (though I consider it less likely ;))

    Any link to the NASA study available? I thought it is fairly old news that only little heat goes into the ocean below 2000 meter (see Purkey and Johnson 2010 for example).

  11. KarSteN,
    It’s from this press release but I couldn’t find an associated paper.

  12. BBD says:

    There are *two* studies (which share an author btw):

    Llovel et al.

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

    And Durack et al.

    http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2389.html

    The misrepresentation of the term “deep ocean” by the denial blogosphere is blatant and silly.

  13. BBD says:

    Did anyone expect to see / claim there was significant warming of the abyssal deeps below 2000m? Er, no.

    So what the fake sceptics are frantically engaging in now is a misrepresentation-cum-strawman.

  14. Andrew Dodds says:

    My understanding is that much of the really deep water is ‘generated’ by and around Antarctica – when the sea ice forms around it and very cold, highly saline left-over water sinks to the bottom. So the temperature and hence heat content would be unaffected until sea ice stops forming around Antarctica.

    At which point things go very wrong indeed – if you transition from a temperature-driven circulation (as we have today), to a salinity-driven circulation, you can heat the entire volume of the ocean by 10+K, induce anoxic events, see sea level rise dozens of meters and even possibly have H2S outgassing, which if it happened would be even less fun than it sounds.

    It would take a few thousand years, though. And you’d have to lose the EAIS first, so it’s not the first thing you should worry about.

  15. Joshua says:

    Can someone give me a ballpark figure for what % of ocean water volume lies below 2000m?

  16. Joshua,
    I think that average depth of the oceans is about 3500m, so it is almost half.

  17. Actually, I’ve just looked it up and it may be as much as 4200m, so slightly more than half. Around half is probably good enough for government work 🙂

  18. BBD says:

    Andrew Dodds

    There is also considerable deep water formation in the high N. Atlantic. The other end of the THC.

  19. The book chapter linked to at the top of this page of Rahmstorf contains more information about the volumes of deep water formation on page 3.

  20. Paul S says:

    Abyssal warming paper is this one: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2387.html

    As people have said, it’s an inverse study, not using any measurements in the abyssal ocean. They essentially find that OHC measurements of the upper-2000m + GRACE ocean mass data can explain all the observed sea level rise (actually more than all), so abyssal warming isn’t necessary to close the sea level budget over 2005-2013.

    I think it’s going a bit far to suggest the paper is particularly definitive on the matter of recent abyssal warming though: their uncertainty range in terms of sea level contribution is -0.85 to +0.59mm/yr, which relates to uncertainties in the GRACE mass estimates, upper-2000m OHC estimates and altimeter SLR measurements.

    I’ve found the AVISO altimeter trend for 2005-2013 is 3.17mm/yr compared to the NASA trend they use which is 2.78mm/yr +/-0.32. Note that the AVISO trend is therefore above their stated SLR uncertainty range. If they had used AVISO for their SLR data they would have found an abyssal SLR contribution of +0.26mm/yr.

  21. @all: Thanks for the paper link!

    @Paul S: It’s only now that I remember having read somewhere that steric SLR component is currently only 30% (I always had 50% in mind, which might still hold over longer time intervals). Thing is, Durack et al. would be inconsistent with this paper (Llovel et al), given that their steric contribution would be larger by almost 50% (which would be >1mm/yr, if I’m not wrong). Either their method is flawed, or GRACE is more uncertain than previously thought.

  22. Mircea says:

    I thought these studies are about heat distribution in the ocean layers. The total heat absorbed remains the same (I.e. delta Q in the equations does not change).
    IMO the point of the studies is that the deep ocean lost heat.

  23. BBD says:

    Mircea

    IMO the point of the studies is that the deep ocean lost heat.

    I don’t think that claim in Llovel et al. is robust.

  24. BBD says:

    I am pretty shocked by the NASA press release, which is full of contentious if not downright wrong statements:

    The cold waters of Earth’s deep ocean have not warmed measurably since 2005, according to a new NASA study, leaving unsolved the mystery of why global warming appears to have slowed in recent years.

    [WRONG]

    In the 21st century, greenhouse gases have continued to accumulate in the atmosphere, just as they did in the 20th century, but global average surface air temperatures have stopped rising in tandem with the gases.

    [WRONG]

    The temperature of the top half of the world’s oceans — above the 1.24-mile mark — is still climbing, but not fast enough to account for the stalled air temperatures.

    [WRONG]

    Many processes on land, air and sea have been invoked to explain what is happening to the “missing” heat. One of the most prominent ideas is that the bottom half of the ocean is taking up the slack, but supporting evidence is slim.

    [WRONG]

    WTF??

    This release needs to be withdrawn, rewritten and re-released with a clearly-stated apology.

  25. ohflow says:

    Greetings people! I just wanted to point out that some person nicknamed “Jimbo” over at WUWT has made a comment as to why this study should be ignored(Ill try my luck at posting an URL):
    http://wattsupwiththat.com/2014/10/06/the-heat-went-to-the-oceans-excuse-and-trenberths-missing-heat-is-awol-deep-ocean-has-not-warmed-since-2005/#comment-1756089
    I am no “skeptic” by the blogospheres definition, but I am also curious as to why he is wrong/correct? I read both WUWT and this blog while on the train from and to work, but I feel the chance is higher at getting a coherent and non-toxic reply here.

    Pardon if my english/grammar is hard to follow, second language and use it very seldom.
    Thanks again for the blog!

  26. Ohflow, that paper deals with some surface measurements, and have nothing to do with the known heating of the bulk subsurface ocean, measured by sea level rise and other means.

    The paper is being misrepresented and you are being mislead and misinformed.

  27. Mircea,
    For the NASA study, they were simply trying to see if the abyssal ocean was warming. The answers appears to be no, but with quite large uncertainties. For the study I discuss here, they are indeed arguing that the OHC estimates are underestimated by a few tens of percent in the 0 – 700m layer.

    ohflow,
    What Jimbo is saying appears to be that they used models to estimate the distribution of energy in the southern and northern hemisphere oceans and adjusted the estimates using those model results and therefore it is wrong. That’s just too simplistic to really be right or wrong. He’s correct that they used models, but that isn’t really a reason to dismiss a study. If the sampling in the Southern Ocean is indeed poor and if the models suggest that the poorly sampled regions have being badly estimated in the past, then the result may be credible. It’s just one paper, but you wouldn’t dismiss it simply because it used models.

  28. To reply to verytallguy October 7, 2014 at 11:16 am, Then There’s Physics October 7, 2014 at 11:20 am, K.a.r.S.t.e.N October 7, 2014 at 12:00 pm, BBD October 7, 2014 at 12:46 pm, and BBD October 7, 2014 at 1:55 pm:

    Thanks so much for the replies and links. And *thank-you* BBD for that 1:55 pm comment! I brought this up in the last thread but got no reply. To reflect what I said, this NASA press release is quite inconsistent (as in BBD’s WRONG! WRONG! WRONG!) with what I though was true, which is based on what I read at real-science-based blogs like Skeptical Science, this blog by ATTP, the Real Climate site, and Open Mind.

    (Side note: Open Mind has been great – but I miss it. No new posts there since late July. I think I’m suffering withdrawal symptoms from lack of in-depth discussions of statistics! Anyone know of other such mathy but real-science-based blogs to point me to? I neglected to echo above what I shared in some prior thread, which is that I have a bachelor’s in math and, although my formal training is essentially is only in math, essentially no science [well, lots of music courses as a music major before I changed majors], I can still get a lot out of such technical posts.)

    Now you know why I said that the deniers are going crazy on this one! (To try to understand how the press release people in NASA could have gotten things so wrong: Perhaps some denier career civil servant in the press section of NASA got away with something?)

  29. [Mod: I’d prefer just a link be posted to NASA contact details in case someone wants to enquire about the press release rather than the contact details themselves posted here. The link is: http://www.nasa.gov/news/media/contacts/ ]

  30. Paul S says:

    Karsten,

    Different timespans. Durack covers 1970-2004 and Llovel covers 2005-2013. Most of the coverage issues identified by Durack don’t appear to apply to the ARGO era. There is an ARGO coverage bias identified by von Schuckmann et al. (among others) which indicates global ARGO datasets have underestimated ocean warming, possibly by as much as 50-60% over 2005-2012 assuming mass contributes about 2/3 of sea level trend over that period. I doubt the ARGO datasets used by Llovel have accounted for this.

    I’m a bit confused by the numbers in the abstract of Llovel et al. They reference ocean warming measurements suggesting a SLR contribution of 0.77mm/yr over 2005-2013, but also that ‘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.’ If they’re talking about an Earth energy imbalance surely they mean a number averaged over the whole Earth surface, not just ocean surface, but I can’t see how a 0.77mm/yr thermosteric trend can be consistent with a TOA imbalance of 0.64W/m2.

  31. Steve Bloom says:

    Given the recent paper combining GRACE and GOCE data for a much more detailed view of WAIS ice loss, I’m wondering if it might not be possible to do the same for the oceans. OTOH these combined gravity satellite studies must not be easy since AFAIK we’ve just seen the one so far and that with a considerable delay relative to when the data was generated.

    DS, if you’re reading could you perhaps comment?

  32. Paul S,

    fair enough. Valid point indeed. Difference in SH OHC contribution between CMIP5 and OBS seems to be converging indeed in Durack et al. So perhaps less correction required after 2004.

    The net warming imbalance is ocean only! It’s 0.72 W/m2 for 0-2000m (corresponding to 7.95ZJ/yr) minus the 0.08 W/m2 they attributed to abyssal change. Clearly, this isn’t for the entire globe. I can’t make any sense of their abstract statement. In fact, I can’t see how it can be interpreted as correct. So it has to be 0.45 W/m2 which would then also be consistent with their thermosteric trend.

  33. Doug Bostrom says:

    Further to BBD’s remarks about the (over-egged?) press release, it’s puzzling that actual sampling of abyssal temperatures seems to broadly indicate warming of the deep ocean. At the minimum, it appears there’s at least a small counterintuitive sign conflict between Durack and sampled temperatures when it comes to contribution to SLR.

    Samples of actual samples:
    Recent Bottom Water Warming in the Pacific Ocean
    Decadal changes of abyssal temperature in the Pacific Ocean are analyzed using high-quality, full-depth hydrographic sections, each occupied at least twice between 1984 and 2006. The deep warming found over this time period agrees with previous analyses. The analysis presented here suggests it may have occurred after 1991, at least in the North Pacific. Mean temperature changes for the three zonal and three meridional hydrographic sections analyzed here exhibit abyssal warming often significantly different from zero at 95% confidence limits for this time period. Warming rates are generally larger to the south, and smaller to the north. This pattern is consistent with changes being attenuated with distance from the source of bottom water for the Pacific Ocean, which enters the main deep basins of this ocean southeast of New Zealand. Rough estimates of the change in ocean heat content suggest that the abyssal warming may amount to a significant fraction of upper World Ocean heat gain over the past few decades.

    Recent western South Atlantic bottom water warming
    [1] Potential temperature differences are computed from hydrographic sections transiting the western basins of the South Atlantic Ocean from 60°S to the equator in 2005/2003 and 1989/1995. While warming is observed throughout much of the water column, the most statistically significant warming is about +0.04°C in the bottom 1500 dbar of the Brazil Basin, with similar (but less statistically significant) warming signals in the abyssal Argentine Basin and Scotia Sea. These abyssal waters of Antarctic origin spread northward in the South Atlantic. The observed abyssal Argentine Basin warming is of a similar magnitude to that previously reported between 1980 and 1989. The Brazil Basin abyssal warming is similar in size to and consistent in timing with previously reported changes in abyssal southern inflow and northern outflow. The temperature changes reported here, if they were to hold throughout the abyssal world ocean, would contribute substantially to global ocean heat budgets.

    Warming and Freshening in the Abyssal Southeastern Indian Ocean
    Warming and freshening of abyssal waters in the eastern Indian Ocean between 1994/95 and 2007 are quantified using data from two closely sampled high-quality occupations of a hydrographic section extending from Antarctica northward to the equator. These changes are limited to abyssal waters in the Princess Elizabeth Trough and the Australian–Antarctic Basin, with little abyssal change evident north of the Southeast Indian Ridge. As in previous studies, significant cooling and freshening is observed in the bottom potential temperature–salinity relations in these two southern basins. In addition, analysis on pressure surfaces shows abyssal warming of about 0.05°C and freshening of about 0.01 Practical Salinity Scale 1978 (PSS-78) in the Princess Elizabeth Trough, and warming of 0.1°C with freshening of about 0.005 in the abyssal Australian–Antarctic Basin. These 12-yr differences are statistically significant from zero at 95% confidence intervals over the bottom few to several hundred decibars of the water column in both deep basins. Both warming and freshening reduce the density of seawater, contributing to the vertical expansion of the water column. The changes below 3000 dbar in these basins suggest local contributions approaching 1 and 4 cm of sea level rise, respectively. Transient tracer data from the 2007 occupation qualitatively suggest that the abyssal waters in the two southern basins exhibiting changes have significant components that have been exposed to the ocean surface within the last few decades, whereas north of the Southeast Indian Ridge, where changes are not found, the component of abyssal waters that have undergone such ventilation is much reduced.

    Etc. Are all of these campaigns so unlucky as to find anomalous hotspots?

  34. Eli Rabett says:

    Now if Eli was filling in for Murray Salby or Bob Tisdale over at WUWT, he would write something like this.

    Almost all of the carbon dioxide on earth is found in the abyssal depths. If the depths were warming then much of that CO2 would come out of solution (aka the warm Coke effect), the fact that the depths are not warming means that CO2 levels are not rising and accounts for the pause in global temperature rise. Further the “observed” rise in CO2 mixing ratio is a fiction caused by volcanic emissions of Mauna Loa.

  35. MMM says:

    Llovel et al. (http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2387.html) is titled, “Deep-ocean contribution to sea level and energy budget not detectable over the past decade”, but in the text they have statements such as, “Therefore, we estimate the heat uptake by the upper 2,000 m of the global ocean to be 0.72 ± 0.1 W m−2. Our estimate is slightly larger than the recently reported estimate of 0.54 ± 0.1 W m−2 for the upper 1,500 m layer27 computed over 2005–2010 and the estimate of 0.56 W m−2 for the 0–1,800 m layer23 over 2004–2011.”

    So, yes, the study finds little abyssal warming, but, burying the lede, they find that the oceans overall have larger warming! (consistent with Durack et al.)

    I do generally like the approach of starting with sea level rise (which we can measure reasonably well) and mass changes (which GRACE gives at least some hope of figuring out) and thereby trying to differentiate steric & mass-based effects. Once you’ve done that, then using ARGO to determine the heat in the upper 2000m (also some uncertainty) allows for calculating the heat below 2000m. So the biggest uncertainties are, by my judgment, the ARGO heat estimation (which only matters for differentiating upper versus lower ocean), the GRACE data (which is key for determining overall ocean heat uptake by this method), and sea-surface altimetry (very certain compared to the others).

    Interestingly, Durack et al. states, “We note that the largest adjusted global values (Ish09 (ref. 10), Lev12 (ref. 11)) are consistent with a recent upper-OHC change estimate12;”

    Reference 12 here is the same reference as reference 23 in my first quote (Lyman & Johnson 2014): so if I combine the two statements (that the Durack adjustments match L&J2014 and that L&J2014 underestimates heat uptake), then even Durack is too small of an upward shift.

    Finally, the other thing I’d like to see is how these increased ocean heat uptake estimates fit in terms of the larger planetary energy balance: e.g., forcing from preindustrial minus increased outgoing forcing due to warmer temperatures should approximately equal system heat uptake.

    -MMM

  36. Sure, Steve. I agree with BBD that the NASA press release is fractally wrong. Natural short-term variability has been acknowledged by scientists for decades, so it’s not a mystery that surface air temperature trends over an extremely short (2005-2013) timespan are extremely variable.

    I don’t know why they claim that air temperatures have “stalled”. Even without considering Cowtan and Way 2013, that’s still not true. Pick any date for the start of this supposed “stall” (like 1998-2014) and calculate the temperature trend and its auto-correlated uncertainty for any dataset. Then calculate the trend and uncertainty for the previous timespan of the same length (like 1982-1998). If their uncertainties overlap, in what sense have air temperatures “stalled”? If they don’t overlap, please let me know which starting date and dataset you used.

    So I don’t know why they claim that ocean warming above 2000m depth “isn’t fast enough” to account for the air temperature trend. The uncertainty for HadCRUT4 air temperatures from 2005-2013 are huge: -0.087 ± 0.311 °C/decade. That just means 8 year timespans are too short to draw conclusions using air temperatures.

    Finally, the notion of abyssal (>2000m depth) ocean warming isn’t prominent. Scientists have just been saying that the oceans absorb ~90% of the heat we’re trapping, so diagnosing Earth’s energy imbalance requires studying the oceans. In contrast, global surface temperatures only absorb ~2% of the heat we’re trapping.

    Here’s co-author Josh Willis explaining that concept at JPL and demonstrating it using balloons and a lighter. It’s only 4 minutes long, and worth watching.

    At Hot Whopper I noted how ironic that WUWT is excited about Llovel et al. 2014, which concludes: “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.”

    In other words, the same people who keep insisting that warming has somehow “paused” are waving around a paper which shows statistically significant warming.

    Frank Knarf already pointed that out, but the WUWTians were too busy accusing scientists of “outright lying” to respond.

  37. @DS,
    Ahhh, no, you made me look 🙂

  38. Oh, I forgot to answer Steve’s actual question about GOCE. GOCE was designed to study extremely short-scale details, which it achieved by flying very low. That required an ion drive to counter atmospheric drag, so GOCE crashed in 2013 when it ran out of fuel. It also makes it very difficult to use GOCE data to study changes in gravity. GOCE was primarily intended to improve our understanding of the Earth’s static (non-changing) background gravity field at very small spatial scales.

    The paper Steve referred to used GOCE’s higher resolution to help GRACE resolve individual basins in West Antarctica.

    But measuring ocean mass primarily involves large spatial scales, so GOCE data isn’t as crucial there.

    One way GOCE might help is that improving resolution would allow us to apply a more accurate coastline mask to separate land from ocean. Most GRACE ocean mass datasets only use GRACE data that’s at least ~300 km away from land. That’s because land signals are ~10x larger than ocean signals, and GRACE has a large “footprint” so land signals contaminate ocean signals even hundreds of kilometers away from the coast.

    I doubt that this would have a large effect on the ocean mass measurements though, because the vast majority of the ocean is more than 300 km away from land.

  39. Paul S says:

    MMM,

    Llovel covers a different timespan (2005-2013) than Durack (1970-2004) in which coverage is generally substantially improved. I don’t think there’s a question of consistency between the two. I suspect the Lyman & Johnson 2014 estimate being referenced by Durack is for 1983-2011 (about 0.61W/m2), not the 2004-2011 one.

    Regarding comparison with other estimates I think the main difference is time rather than any structural improvements in the data. If you look at the OHC time series there is a big step up in 2013. It looks like their 2005-2011 estimate would be similar to their references. With data so far for this year 2005-2014 will probably be another leap up, to about 0.8W/m2.

  40. Steve Bloom says:

    Much thanks, DS!

  41. Infopath says:

    There’s one refreshing consequence to the NASA press release, IMO, especially since it had the predictable arm-waving effect on “skeptics:”

    Those who take the info in the article at face value, can’t at the same time claim that climate scientists (from a dot-gov site no less!) are under so much pressure that they fudge data and only publish findings that completely conform with AGW.

    That a lot of the info in the NASA article is wrong (as pointed out by BBD), can be a bit puzzling… or…

    Is NASA playing ClimateBall™? 😉

  42. Infopath: Ironically, I decided against emailing the press release authors because even if that led to a correction, it would just “confirm” pressure to conform with AGW. Self-sealing ideologies are invulnerable.

  43. Steve Bloom says:

    DS, I guess you would have some inside knowledge about this, so was it an error by a PR type or were the authors of the paper involved?

  44. Steve Bloom says:

    Crap, I had to go and look too.

    But I did find this gem, so bad it’s some kind of good:

    There are 3000 argo floats in the ocean. By comparison, there are thought to be 9000 blue wales in the ocean. That’s three times as many blue wales as there are argo floats.
    There are so few of them that if argo floats were alive they would be a protected species.
    If that’s what we have to rely on, then nobody knows anytime about ocean heat content.

  45. Actually, I don’t have much inside knowledge. But all the authors’ direct quotes in that press release seem reasonable, as well as all the statements in the Llovel et al. 2014 abstract. I think this is just another example of how insidious repetitive misinformation is, and how difficult it is to communicate complex science in ways that are compelling and draw eyeballs without also accidentally implying that previous research was somehow inadequate.

  46. My acid test for someone calculating TCR is if they do the algebra of Land+Ocean correctly. That’s why I think Lewis and Curry are low-balling it. See this derivation:
    http://contextearth.com/2014/01/25/what-missing-heat/

  47. Susan Anderson says:

    Now that’s a whale of a lot of malarkey. What exactly is a blue wale?

    But seriously, after at least 10 years of being battered with continuous garbage, the kind of stuff SkS is hated for cleanly eviscerating, how can anyone claim that the inability to ever acknowledge any kind of error, make any correction, or even admit that clean energy might, in principle, be a good thing to develop, is rational. It is intended to cause doubt and delay, purely and simply. There is no “there” there, never has been, never will be.

    Letting people move the goalposts is a mug’s game.

    Speaking of which, “consensus” is only a word. It means almost all experts have come to the same conclusions.

    The confusionists never let up.

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