January to March 2011 NODC Ocean Heat Content (0-700Meters) Update and Comments

INTRODUCTION

The National Oceanographic Data Center’s (NODC) Ocean Heat Content (OHC) anomaly data for the depths of 0-700 meters are available through the KNMI Climate Explorer Monthly observations webpage. The NODC OHC dataset is based on the Levitus et al (2009) paper “Global ocean heat content (1955-2008) in light of recent instrumentation problems”. Refer to Manuscript. It was revised in 2010 as noted in the October 18, 2010 post Update And Changes To NODC Ocean Heat Content Data. As described in the NODC’s explanation of ocean heat content (OHC) data changes, the changes result from “data additions and data quality control,” from a switch in base climatology, and from revised Expendable Bathythermograph (XBT) bias calculations.

The OHC anomaly data is provided from the NODC on a quarterly basis. There it is available globally and for the ocean basins in terms of 10^22 Joules. The KNMI Climate Explorer presents the quarterly data on a monthly basis. That is, the value for a quarter is provided for each of the three months that make up the quarter, which is why the data in the following graphs appear to have quarterly steps. Furnishing it in a monthly format allows one to compare the OHC data to other datasets that are available on a monthly basis. The data is also provided on a Gigajoules per square meter (GJ/m^2) basis through the KNMI Climate Explorer, which allows for direct comparisons of ocean basins, for example, without having to account for surface area.

This update includes the data through the quarter of January to March 2011. The Global and Tropical Pacific OHC anomalies both rose during the first quarter of 2011, as one would expect in response to a La Niña event. This relationship with ENSO is very apparent when OHC data is compared to SST data. Refer to Sea Surface Temperature Versus Ocean Heat Content Anomalies.

GLOBAL

The Global OHC data through March 2011 is shown in Figure 1. Even with the slight rise this quarter, it continues to be remarkably flat since 2003, especially when one considers the magnitude of the rise that took place during the 1980s and 1990s.

Figure 1

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TROPICAL PACIFIC

Figure 2 illustrates the Tropical Pacific OHC anomalies (24S-24N, 120E-90W). The major variations in tropical Pacific OHC are related to the El Niño-Southern Oscillation (ENSO). Tropical Pacific OHC drops during El Niño events and rises during La Niña events. As discussed in the update for October to December 2010, the Tropical Pacific had not as of then rebounded as one would have expected during the 2010/11 La Niña event. It finally responded during the last quarter.

Figure 2

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For more information on the effects of ENSO on global Ocean Heat Content, refer to ENSO Dominates NODC Ocean Heat Content (0-700 Meters) Data and to the animations in ARGO-Era NODC Ocean Heat Content Data (0-700 Meters) Through December 2010.

BASIN TREND COMPARISONS

Figure 3 and 4 compare OHC anomaly trends for the ocean basins, with the Atlantic and Pacific Ocean also divided by hemisphere. Figure 3 covers the full term of the dataset, 1955 to present, and Figure 4 shows the ARGO-era data, starting in 2003. The basin with the greatest short-term ARGO-era trend is the Indian Ocean, but it has a long-term trend that isn’t exceptional. (The green Indian Ocean trend line is hidden by the dark blue Arctic Ocean trend line.) The basin with the greatest rise since 1955 is the North Atlantic, but it also has the largest drop during the ARGO-era. Much of the long-term rise and the short-term flattening in Global OHC are caused by the North Atlantic. If the additional long-term rise and the recent short-term decline in the North Atlantic OHC are functions of additional multidecadal variability similar to the Atlantic Multidecadal Oscillation, how long will the recent flattening of the Global OHC persist? A couple of decades?

Figure 3

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Figure 4

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Further discussions of the North Atlantic OHC anomaly data refer to North Atlantic Ocean Heat Content (0-700 Meters) Is Governed By Natural Variables. And if you’re looking into natural impacts on OHC, also consider North Pacific Ocean Heat Content Shift In The Late 1980s.

ARGO-ERA MODEL-DATA COMPARISON

Many of you will recall the discussions generated by the simple short-term comparison graph of the GISS climate model projection for global OHC versus the actual data, which is comparatively flat. The graph is solely intended to show that since 2003 global ocean heat content (OHC) anomalies have not risen as fast as a GISS climate model projection. Tamino, after seeing the short-term model-data comparison graph in a few posts, wrote the unjustified Favorite Denier Tricks, or How to Hide the Incline. I responded with On Tamino’s Post “Favorite Denier Tricks Or How To Hide The Incline”. And Lucia Liljegren joined the discussion with her post Ocean Heat Content Kerfuffle. Much of Tamino’s post had to do with my zeroing the model-mean trend and OHC data in 2003.

While preparing the post GISS OHC Model Trends: One Question Answered, Another Uncovered, I reread the paper that presented the GISS Ocean Heat Content model: Hansen et al (2005), “Earth’s energy imbalance: Confirmation and implications”. (PDF) Hansen et al (2005) provided a model-data comparison graph to show how well the model matched the OHC data. Figure 5 is Figure 2 from that paper. As shown, they limited the years to 1993 to 2003 even though the NODC OHC data starts in 1955. Hansen et al (2005) chose 1993 as the start year for three reasons. First, they didn’t want to show how poorly the models hindcasted the early version of the NODC OHC data in the 1970s and 1980s. The models could not recreate the hump that existed in the early version of the OHC data. Second, at that time, the OHC sampling was best over the period of 1993 to 2003. Third, there were no large volcanic eruptions to perturb the data. But what struck me was how Hansen et al (2005) presented the data in their time-series graph. They appear to have zeroed the model ensemble mean and the observations at 1993.5. The very obvious reason they zeroed the data then was so to show how well OHC models matched the data from 1993 to 2003.

Figure 5

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My ARGO-era model-data comparison graph is also zeroed at the start year, 2003, but I’ve done that to show how poorly the models now match the data. Hansen et al (2005) zeroed at 1993 to show how well the models recreated the rise in OHC from 1993 to 2003 and I’ve zeroed the data in 2003 to show how poorly the models match the data after that. I’m not sure why that’s so difficult to accept for some people. The reality is, the flattening of the Global OHC anomaly data was not anticipated by those who created the models. This of course raises many questions, one of which is, if the models did not predict the flattening of the OHC data in recent years, much of which is based on the drop in North Atlantic OHC, did the models hindcast the rise properly from 1955 to 2003?

Figure 6 compares the ARGO-era Ocean Heat Content observations to the model projection, which is an extension of the linear trend determined by Hansen et al (2005), for the period of 1993 to 2003. Over that period, the modeled OHC rose at 0.6 watt-years per year. I’ve converted the watt-years to Gigajoules using the conversion factor readily available through Google: 1 watt years = 31,556,926 joules. The model projection has risen at a rate that’s 7 times higher than the observations since 2003.

Figure 6

I asked the question in Figure 6, If The Observations Continue To Diverge From The Model Projection, How Many Years Are Required Until The Model Can Be Said To Have Failed? It’s really a moot point. Hansen et al (2005) shows that the model mean has little-to-no basis in reality. They describe their Figure 3 (provided here as Figure 7 in modified form) as, “Figure 3 compares the latitude-depth profile of the observed ocean heat content change with the five climate model runs and the mean of the five runs. There is a large variability among the model runs, revealing the chaotic ‘ocean weather’ fluctuations that occur on such a time scale. This variability is even more apparent in maps of change in ocean heat content (fig. S2). Yet the model runs contain essential features of observations, with deep penetration of heat anomalies at middle to high latitudes and shallower anomalies in the tropics.” I’ve deleted the illustrations of the individual model runs in Figure 7 for an easier visual comparison of the observations and the model mean graphics. I see no similarities between the two. None.

Figure 7

COMPARISON OF OHC ANOMALY DATA BY HEMISPHERES

I don’t recall presenting the OHC anomalies for the Northern and Southern Hemisphere on the same graph in earlier posts, so here they are in Figure 8. As always, the Southern Hemisphere data has to be taken with more than a grain of salt. There were very few observations in the Southern Hemisphere prior to the ARGO era, especially south of the tropics. But what I found interesting was the major divergence after the 1997/98 El Niño. The Northern Hemisphere data rises significantly, but there is a minor dip and rebound in the Southern Hemisphere data at that time.

Figure 8

So I subtracted the Southern Hemisphere OHC anomaly data from the Northern Hemisphere. Refer to Figure 9. The timing of the large variations appear to coincide with El Niño-Southern Oscillation (ENSO) events. I checked and found that they did, but the results were surprising.

Figure 9

Figure 10 is a gif animation that compares inverted and scaled (-0.1) NINO3.4 SST anomalies (a commonly used proxy for the timing and magnitude of ENSO events) and the difference between Northern and Southern Hemisphere OHC anomalies. The animation presents the inverted NINO3.4 SST anomalies shifted up and down. I’ve done this to align them with the corresponding changes in the hemispheric difference for the significant 1972/73, 1982/83, and 1997/98 El Niño events. The hemispheric difference leads the NINO3.4 SST anomalies during those ENSO events.

Figure 10

I have not carried the investigation any farther. Hopefully soon.

THE HEMISPHERES AND THE OCEAN BASINS

(11) Northern Hemisphere

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(12) Southern Hemisphere

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(13) North Atlantic (0 to 75N, 78W to 10E)

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(14) South Atlantic (0 to 60S, 70W to 20E)

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(15) North Pacific (0 to 65N, 100 to 270E, where 270E=90W)

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(16) South Pacific (0 to 60S, 120E to 290E, where 290E=70W)

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(17) Indian (60S-30N, 20E-120E)

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(18) Arctic Ocean (65 to 90N)

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(19) Southern Ocean (60 to 90S)

SOURCE

All data used in this post is available through the KNMI Climate Explorer:

http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

About Bob Tisdale

Research interest: the long-term aftereffects of El Niño and La Nina events on global sea surface temperature and ocean heat content. Author of the ebook Who Turned on the Heat? and regular contributor at WattsUpWithThat.
This entry was posted in OHC Update. Bookmark the permalink.

14 Responses to January to March 2011 NODC Ocean Heat Content (0-700Meters) Update and Comments

  1. lgl says:

    …as one would expect in response to an El Niño event http://virakkraft.com/Radiative-imbalance-ENSO.png

  2. Dennis Hlinka says:

    Hi Bob,

    Looking at the plot of the Indian Ocean heat content (Fig 17), I find the pattern remarkably consistent with the plot of Indian Ocean SSTs going back to 1860: http://www.pnas.org/content/105/32/11081/F2.large.jpg (Fig 2 from this 2007 report: http://www.pnas.org/content/105/32/11081.full).

    The dramatic recent increase of heat content in the Indian Ocean also appears to be consistent with model forecasts of increased precipitation over the ocean as a likely response to anthropogenic warming of temperatures in that region: http://www.pnas.org/content/105/32/11081/F3.large.jpg (Fig 3 from that same report).

    My question to you is: Are the noted increases in heat content and the timeline plot of SSTs in the Indian Ocean providing a “more reliable” example of a hockey stick formation relating to a recent rapid increase in temperatures over a key area of the globe and quite likely possibly due to anthropogenic influences? If not, why not?

    Also it appears that the Southern Hemisphere (SH) is playing catch up with the Northern Hemisphere (NH), as temperatures and heat content have tended to stall out in the NH. So even though the global heat content has flattened out since 2003 as you noted, what happens if this global heat content actually begins to increase again and tops the 2003 peak? How will that potential exceedance be played in regards to those forecasting that the next mini ice age is coming?

    Just curious.

  3. Bob Tisdale says:

    Dennis Hlinka: First, I have to ask: What happened? Why the sudden interest in my blog? Did your mouthing off here about D’Aleo and Bastardi get you banned from their blog?

    You asked, “Are the noted increases in heat content and the timeline plot of SSTs in the Indian Ocean providing a “more reliable” example of a hockey stick formation relating to a recent rapid increase in temperatures over a key area of the globe and quite likely possibly due to anthropogenic influences? If not, why not?”

    No. The Indian Ocean has only been sampled fully since 2004/05 for OHC. And as you are very much aware, I find little evidence of an anthropogenic global warming signal in SST or OHC.

    You wrote, “Also it appears that the Southern Hemisphere (SH) is playing catch up with the Northern Hemisphere (NH), as temperatures and heat content have tended to stall out in the NH. So even though the global heat content has flattened out since 2003 as you noted, what happens if this global heat content actually begins to increase again and tops the 2003 peak? How will that potential exceedance be played in regards to those forecasting that the next mini ice age is coming?”

    I personally don’t care about other people’s forecasts about an upcoming mini ice age. I find them as credible as a GCM forecast of catastrophic global warming. I would recomment go to another blog where people make forecasts of a mini ice age and ask them directly.

  4. Pingback: Anonymous

  5. HR says:

    Hello Bob,

    This is a little bit OT but I thought you may be interested in this for future posts on OHC. I went back to Hansen 2011 to see what he had written about OHC.
    http://www.columbia.edu/~jeh1/mailings/2011/20110415_EnergyImbalancePaper.pdf

    Much of the text discusses von Schuckmann 2011 for the recent trends. I went looking for vS2011 to find that it is a paper still under review and discussion, you can find it here.
    http://www.ocean-sci-discuss.net/8/999/2011/osd-8-999-2011-discussion.html

    The abstract reads ( and Hansen used this figure)
    “A global ocean heat content change (OHC) trend of 0.55±0.1Wm−2 is estimated over the time period 2005–2010.”

    At first glance this seems to be wrong although the change in units is confusing me. The NODC data seems to be flat. It’s also complicated by the fact that vS does not show the data in graphical form. Can you please run your eye over this and let me know if you think some is going wrong here. The paper is still open for discussion so I guess it offers you the opportunity to get involved at the review stage of the paper.

    Thanks

  6. HR says:

    Ok Bob, I reread your article and noticed it contains the necessary info. The 0.55±0.1Wm−2 in 2005-2010 looks as though it would represent a near continuation of the 1993-2003 (0.6Wm-2) rate which seems far from what NODC is showing. It’d be interesting to see how vS derives their rate.

  7. Bob Tisdale says:

    HR: Thanks for the links. The von Schuckmann (2011) estimate of 0.55 watts/m^2 you mentioned for OHC is based on depths of 10 to 1500 meters, while Levitus et al/NODC is based on 0 to 700 meters. At the bottom of page 29, Hansen et al (2011) also list von Schuckmann heat gain of 0.45 watts/m^2 for depths of 0 to 700 meters.

  8. Dennis Hlinka says:

    Hi Bob,

    Things seem to gotten pretty slow here on your site, so I thought I would reply to your earlier response to me.

    No I can’t say if I have been banned from their site since I have not yet tried to get back on it recently. I was able to complete what I wanted to say about them and I am basically done. That is until they start spreading more scientifically erroneous reports or analyses either directly or through their public misinformation distribution network.

    I have simply come back here to your publicly accessible blog site, after having to take some time to do more important things with my life, to simply ask some further questions, since you present yourself here as an authority on this particular subject of OHC and SSTs. All I want to do is pick your brain about it and why you are so confident in non-anthropogenic forces are involved, if that is OK with you.

    If I may, would you be kindly willing to take some thought time to hopefully respond to these following questions?

    Based on this chart you posted from your May 22 posting:

    I can see that the OHC and HADSST data correlates very well after the 2004/2005, as you suggest is the time when OHC was more fully sampled. This suggests to me that the SST data is much more reliable prior to 2004 than OHC (even though the general long term trends of both are about the same in that chart of yours).

    My question to you is, due to this apparently very highly correlated data after 2004, would you expect (or not expect) OHC data, if it existed and was fully sampled, to at least be comparable in relative pattern and magnitude with the “more reliable” HADSST data starting from 1955 up to 2004?

    Let’s go back even further. How about with the SST data that goes back to 1860 from the chart that I linked to earlier: http://www.pnas.org/content/105/32/11081/F2.large.jpg? If you actually would consider that a fairly good representation between the two OHC and SST data sets could possibly exist, could the Indian Ocean SST data going back to 1860 present a fairly reasonable representation of OHC content (again if it was fully sampled) going back to that time? How about an even longer period if a reliable proxy paleoclimate SST data set exists for that region?

    Again since I have to anticipate your answers above, if there could possibly be a fairly reasonable representation of pattern and magnitude between OHC and SST in the Indian Ocean for a much longer period of time, then if the tropical SSTs in the Indian Ocean may presently be the highest than they have been in the last 120,000 years (http://www.pnas.org/content/103/39/14288.full.pdf+html), then couldn’t it be possible that this also could indicate that OHC in the Indian Ocean could also be at their highest levels they has ever been in 120,000 years? Again assuming your answer to my question is at least possible, what natural force/cycle data would you have or know of that would adequately account for this apparently recent rapid OHC increase to levels not seen for 120,000 years if not recently anthropogenically produced? What is different now compared to 120,000 years ago?

    I think this is an important climate change question for you to seriously consider since you so confidently believe otherwise based on what I consider a relatively short-term data set and not really addressing the longer term record that is more directly applicable for any climate change analysis considerations.

    If I look further at a long-term chart of CO2 concentrations for the past 600,000+ years: http://www.realclimate.org/epica.jpg
    and I see the recent much higher peak of CO2 concentrations compared to the last peak around 120,000 years with a serious CO2 concentration minimum in the years in between, and the temperature proxy graphs for various global regions, including the Indian Ocean showing fairly similar patterns, the long-term data is saying something different from your position that totally discounts anthropogenic forces? What natural forces do you know of or can point to that covers this extended 120,000 year time period with a similar pattern that tells you otherwise? If you can’t answer that question or provide any reasonable scientifically valid data to support your position that can explain how the most recently observed global temperature and OHC changes and apparent peaks above previous long-term peaks are all due to complete natural causes/cycles, then I personally do not think that you have fully considered a large enough data base in order to support your particular position enough.

    Let’s keep the facts scientifically based!

  9. Bob Tisdale says:

    Dennis Hlinka: I provided you with an answer to this question on the earlier thread, did I not? Why are you reasking it here where it does not belong?

  10. Pingback: >Links To NODC Ocean Heat Content Posts | Bob Tisdale – Climate Observations

  11. Pingback: April to June 2011 NODC Ocean Heat Content Anomalies (0-700Meters) Update and Comments | Bob Tisdale – Climate Observations

  12. Pingback: Tisdale on Ocean Heat Content Anomalies | Watts Up With That?

  13. Pingback: July to September 2011 NODC Ocean Heat Content Anomalies (0-700Meters) Update and Comments | Bob Tisdale – Climate Observations

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