ENSO Dominates NODC Ocean Heat Content Data
Guest post by Bob Tisdale, BTW here is the current SST map. – Anthony
The Royal Netherlands Meteorological Institute (KNMI) recently added the National Oceanographic Data Center (NODC) Ocean Heat Content (OHC) dataset to their Climate Explorer website, allowing users to download data based on user-defined global coordinates.
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
This OHC dataset was presented in the Levitus et al (2009) paper “Global ocean heat content(1955-2008) in light of recent instrumentation problems” [GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L07608, doi:10.1029/2008GL037155, 2009]
ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat08.pdf
There are differences in the presentation of the data. The NODC illustrates their OHC data in 10^22 Joules, but KNMI presents the data on an area-averaged basis, in units of Gigajoules (10^9 Joules) per square meter. The data is the same; the units in which the data is presented are different. Also, the NODC provides the data on a quarterly basis; that is, the data is grouped in three-month averages. KNMI presents the NODC OHC data on a monthly basis by listing the quarterly data for each of the three months. This is why the OHC data appears to be squared off in the graphs of monthly raw data. This can be seen in Figure 1.
http://i32.tinypic.com/29de5ow.png
Figure 1
Figure 1 is a comparison graph of the Global OHC anomaly data (NODC), scaled NINO3.4 SST Anomalies (HADISST), and scaled Sato Index (GISS) data. This is the same format used in the graphs of the subsets illustrated in this post. The NINO3.4 SST anomalies are used to illustrate the timing of the El Nino-Southern Oscillation (ENSO) events. The Sato Index of Mean Optical Thickness at 500nm are provided to illustrate the timing of explosive volcanic eruptions. I’ve also smoothed the data for each OHC anomaly subset with a 13-month running-average filter, Figure 2. As you will see later, some of the subsets are noisy in their raw form.
http://i32.tinypic.com/sno57l.png
Figure 2
In the following, I’ve provided links to the graphs of the raw data, for those who are interested in seeing it in that form, but I have only posted the graphs of the data smoothed with a 13-month running-average filter. It’s much easier to see the step changes when the data is in that form.
TROPICS
The Tropical Pacific OHC anomaly data is illustrated in Figure 3. A number of things to note: The tropical Pacific OHC anomalies fall during El Nino events, but then recharge during the La Nina. For the most part, when the El Nino events occur at the same time as volcanic eruptions, the recharge does not return the OHC anomalies to the value they were at before the El Nino, but if the El Nino occurs without the influence of a volcanic eruption, the La Nina recharges the Tropical Pacific OHC anomalies to the pre-El Nino level. And it does it quickly. Note also how the 1972/73 El Nino event causes an upward step in the OHC anomalies of the Tropical Pacific. The OHC anomalies then decrease gradually, being influenced by the eruptions of El Chichon in 1982 and Mount Pinatubo in 1991, until they rise suddenly in 1995. In an earlier post, I illustrated how a shift in Tropical Pacific Total Cloud Amount may have caused the 1995 rise in Tropical Pacific OHC, providing fuel for the 1997/98 El Nino. Refer to my post Did A Decrease In Total Cloud Amount Fuel The 1997/98 El Nino?
http://i25.tinypic.com/wrz71x.png
Figure 3
http://i31.tinypic.com/2s96hd1.png
Figure 3 Raw
However, the Tropical Indian Ocean OHC anomaly data reveals a sudden decline in 1995. Did a shift of warm water from the Tropical Indian Ocean to the Tropical Pacific also fuel the 1997/98 El Nino? I’ll investigate this in a future post. Note how the Tropical Indian Ocean OHC anomalies correlate with NINO3.4 SST anomalies over a large portion of the term of the data, but after 1995, the amplitude of the variations changes drastically.
http://i25.tinypic.com/atkaa8.png
Figure 4
http://i30.tinypic.com/xfnk14.png
Figure 4 Raw
In Figure 5, I’ve combined the OHC anomaly data for the Tropical Indian and Pacific Oceans. The OHC anomaly data for this subset follows the base of the NINO3.4 SST anomalies remarkably well. The OHC anomalies of the Tropical Indian and Pacific Oceans follow the rise in NINO3.4 SST anomalies after the 1972/73 and 1997/98 El Nino events. In other words, like the Tropical Pacific, there also appears to be a 25-year decay after the upward step from the 1972/73 El Nino (also influenced by the 1982 and 1991 volcanic eruptions), until the 1997/98 El Nino causes another upward step.
http://i26.tinypic.com/2j60dfp.png
Figure 5
http://i28.tinypic.com/2a3y2a.png
Figure 5 Raw
The step changes in the Tropical Atlantic OHC anomalies are obvious. The first occurred three years after the peak of 1972/73 El Nino, as the NINO3.4 SST anomalies rose from the secondary minimum of the two-year La Nina event. The same thing occurred with the next significant El Nino that was strong enough to generate a La Nina that lasted through two ENSO seasons, and that was the 1997/98 El Nino. Note also how the OHC anomalies of the Tropical Atlantic have been dropping quickly since 2005. Click on the link to the raw data (Figure 6 Raw) to see just how precipitous that drop has been in recent years.
http://i28.tinypic.com/1jnp87.png
Figure 6
http://i28.tinypic.com/2a3y2a.jpg
Figure 6 Raw
MID-TO-HIGH LATITUDES
The North Pacific OHC anomalies are like no other OHC subset. In 1967, there was a sudden drop in the North Pacific OHC anomalies. Twenty plus years later North Pacific OHC anomalies rebounded. I’ll have to investigate this dataset further in a later post, to try to isolate where the majority of that variability takes place.
http://i28.tinypic.com/f56pfm.png
Figure 7
http://i29.tinypic.com/rwp8ut.png
Figure 7 Raw
As illustrated in Figure 8, the South Pacific OHC anomalies show a sharp upward step change following the 1997/98 El Nino. Between 1971 and 1996, the OHC anomalies oscillate at or near 0 GJ/sq meter. The cause of the small rise between the 1960s and 1970 is elusive, but it’s not a significant rise compared to the upward step after the 1997/98 El Nino.
http://i26.tinypic.com/xuhkn.png
Figure 8
http://i27.tinypic.com/25s5ta1.png
Figure 8 Raw
The South Indian Ocean OHC anomaly data, Figure 9, shows a decrease from 1955 until the late 1960s. Then the 1968/69/70 El Nino caused a minor rise in OHC anomalies. This was followed by a major upward step from the 1972/73 El Nino. OHC anomalies in the South Indian Ocean remained relatively flat until the eruption of Mount Pinatubo, when the OHC anomalies dipped. The upward step change after the 1997/98 El Nino is hard to miss. The decay until 2006 almost returned the South Indian Ocean OHC anomalies to the pre-1997/98 values, but the El Nino of 2006/07 bumped it back up again.
http://i31.tinypic.com/34jamtj.png
Figure 9
http://i31.tinypic.com/2dqvpfl.png
Figure 9 Raw
The North Atlantic OHC anomaly data, Figure 10, with its gradual climb, is clearly dominated by the Atlantic Multidecadal Oscillation. The impacts of ENSO events are visible, however. In a future post, I may detrend the North Atlantic OHC anomaly data to emphasize the ENSO impacts on this dataset.
http://i25.tinypic.com/2s17wpt.png
Figure 10
http://i32.tinypic.com/swa4xf.png
Figure 10 Raw
There is a clear step change in the South Atlantic OHC anomaly data, Figure 11, following the 1972/73 El Nino. In this case, however, the response appears to be lagged an extra couple of years. The response is so long, it appears to result from the lesser El Nino of 1976/77. The South Atlantic OHC anomalies remain relatively flat until they appear to respond to the 1997/98 El Nino with an upward step that starts again many years after the peak of the El Nino. Why so long?
http://i30.tinypic.com/2n9xsv6.png
Figure 11
http://i25.tinypic.com/2qdcx7l.png
Figure 11 Raw
Could the variations in the South Atlantic OHC anomalies simply be lagged responses to the Tropical Atlantic OHC anomalies, with surface and subsurface currents transporting the waters from the tropics to the mid-to-high latitudes of the South Atlantic? Refer to Figure 12.
http://i28.tinypic.com/2uffyfr.png
Figure 12
ARCTIC AND SOUTHERN OCEANS
I’ve provided the Arctic and Southern Ocean OHC anomaly data in Figures 13 and 14, without commentary, for those who are interested in seeing what those curves look like.
http://i31.tinypic.com/23u23cz.png
Figure 13
http://i28.tinypic.com/wa0tu0.png
Figure 13 Raw
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http://i28.tinypic.com/53ve2w.png
Figure 14
http://i28.tinypic.com/2niwilg.png
Figure 14 Raw
CLOSING
It is clear that significant El Nino events can and do cause upward step changes in Ocean Heat Content. This indicates that ENSO events do more than simply release heat from the tropical Pacific into the atmosphere. Apparently, El Nino events also cause changes in atmospheric circulation in ways that impact Ocean Heat Content. If and when GCMs are able to recreate the variations in atmospheric circulation that cause these changes in Ocean Heat Content, GCMs may have value in predicting future climate variability. At present, they do not.
SOURCES
The NINO3.4 SST anomaly data is based on HADISST data available through the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
Sato Index data is available through GISS:
http://data.giss.nasa.gov/modelforce/strataer/
Specifically:
http://data.giss.nasa.gov/modelforce/strataer/tau_line.txt
Stephen Skinner: You asked, “Who determines what is anomalous and who has set the standards?”
The anomalies are the difference between the value for a given month and the average of the values for that same month from 1971 to 2000.
par5: You asked, “Do the trade winds intensify El Nino, or does it work the other way around (thermal expansion)?”
The relaxation of the trade winds allows the warm water from the Pacific Warm Pool to travel east. This fuels the El Nino. There’s more on the relationship between trade winds and El Nino events here:
http://faculty.washington.edu/kessler/occasionally-asked-questions.html#q1
coaldust: You wrote, “I’m looking and the SST anomaly graph. Seems strange to have cold (negative anomaly ) water near the equator at 120 W during a developing El Nino. There are several other small areas of negative anomaly where I expect to see warmer water.”
Here’s another graph of the only SST anomaly data included in those graphs.
http://i27.tinypic.com/2cnjh4o.png
The dataset covers the SST anomalies of the grid with the coordinates of 5S-5N, 170W-120W. El Nino conditions only exist if the SST anomalies are above 0.5 deg C. So your statement confused me.
I think ocean heat content is a far more important AGW parameter than global temperature. After all, the oceans’ heat capacity is roughly a thousand times that of the atmosphere,
How does one “reliably” measure oceanic heat content of the entire ocean volume?
I presume its done (historically) with temperature sensors of questionable accuracy measuring mostly ocean surface temperatures. I assume the coverage is “spotty” on the ocean surface and very lacking at depth. These data are subsequently “manipulated” to provide an “estimated” global ocean heat value that includes the ocean depths. These days satellites come into play.
Are the raw data and methods public? Have they been independently audited and proven to provide the information and accuracy needed to make trillion dollar policies?
Skeptical minds want to know.
kim: “Might not this be one aspect of the negative feedback of water vapor? With greater atmospheric temperature may there not be relatively less water vapor in the atmosphere, and fewer clouds, lesser albedo, and greater absorption of the sun’s energy by the oceans during episodes of El Nino?”
The ISCCP Global Total Cloud Amount data tends to agree with your thoughts:
http://www.leif.org/research/cloud-cover.png
From Leif’s comment here (#397)
http://www.climateaudit.org/?p=2983
But ICOADS ocean cloud cover data does not agree:
http://bobtisdale.blogspot.com/2008/12/ocean-cloud-cover-data.html
To All: I was in such a hurry to write this post I forgot to list the depth. It’s the 0 to 700 meter layer. Sorry.
There can’t be an AGW equation for heat content. The way we’re told climate works is that longwave causes warming. Longwave doesn’t penetrate oceans – they require a large amount of SW radiation to heat because of their high heat capacity.
Its a little known fact that water contracts (at around 4C) when it heats and expands when it cools.
nothing about water is mechanical
Good stuff Bob.
Can we see all the ocean basins charted against each other (there is a difference in the scale for one thing. Maybe one with the Nino 3.4 and one without since there will be many lines on the chart).
I asked why heat content is expressed in joules per [unit of area] and Bob Tisdale was kind enough to post the following: “The KNMI Climate Explorer calculates weighted averages of the grids (with data) that are enclosed by the coordinates selected by the user.”
Unfortunately I am now even more mystified. Does this mean there is some standard column of water presumed by this measure? And does that mean we’re looking at the energy content of a relatively thin shell of ocean?
(I will attempt to find my own answers independently now, but I am pretty sure I am not the only person puzzled by this.)
I sense that I am missing something. I have heard astute scientists say that “there is no warming in the pipeline” but the Global Ocean Heat Content in the first graph would seem to suggest otherwise. There has been a quite persistent increase in the brown line for the last forty years.
An Inquirer: You wrote, “I sense that I am missing something. I have heard astute scientists say that ‘there is no warming in the pipeline’ but the Global Ocean Heat Content in the first graph would seem to suggest otherwise. There has been a quite persistent increase in the brown line for the last forty years.”
Looking at the global dataset, there has been no increase in OHC in the past few years. Also, this post illustrated that most if not all of the rise over the past forty years is a function of a natural variable, ENSO.
Roy, you asked, “Does this mean there is some standard column of water presumed by this measure? And does that mean we’re looking at the energy content of a relatively thin shell of ocean?”
The data that KNMI downloaded from NODC presented the OHC for each 1 deg ocean grid, from 0 to 700 meters in depth. I apologize for not listing the depth in the post.
Bob Tisdale
How difficult would be for you to run Southern Hemisphere Heat Content and HADCRUT3? Also where would I find Southern Pacific SST anomalies table data . I have found a close correlation between Southern Hemisphere SST and Hadcrut3gl
Bill Illis: You asked, “Can we see all the ocean basins charted against each other (there is a difference in the scale for one thing. Maybe one with the Nino 3.4 and one without since there will be many lines on the chart).”
A future post. I’ll provide a link in a couple of days when its done. But in the mean time, I’ve already posted that from the yearly data available at the NODC website:
http://i40.tinypic.com/23rpmc7.jpg
From this post:
http://bobtisdale.blogspot.com/2009/05/levitus-et-al-2009-ocean-heat-content.html
An Inquirer: Sorry, I missed responding to the pipeline portion of your comment. Dr. Pielke’s argument is provided in this post:
http://wattsupwiththat.com/2009/03/05/pielke-sr-no-climate-heating-in-%E2%80%9Cthe-pipeline%E2%80%9D/
It reads:
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By “unrealized warming in the pipeline”, they mean heat that is being stored within the ocean, which can subsequently be released into the ocean atmosphere. It is erroneous to consider this heat as ”unrealized warming”, if the Joules of heat are actually being stored in the ocean. The heat is “realized”; it would just not be entering the atmosphere yet.
As discussed in the Physics Today paper
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55,
there has been no heating of the upper ocean since mid-2003. Moreover, there has been no heating within the troposphere (e.g. see Figure 7 of the RSS MSU data).
Thus, there is no “warming in the pipeline” using the author’s terminology, nor any heating within the atmosphere! Perhaps the heating that was observed prior to 2003 will begin again, however, it is scientifically incorrect to report that there is any heat that has not yet been realized within the climate system.
The answer to the question posted in this weblog “Is There Climate Heating In “The Pipeline”? is NO.
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GOHC seems to go its own way up, resembling Hansen´s hockey stick. Why is it so?
It seems to me like that sudden cooling in Tropical Indian Ocean heat content, with a double dip first at about 1997, and than the bigger dip in 1999-200, could be best explained by a sudden upwelling of deep cold water in the Indian ocean.
Perhaps an overturning event of some sort?
The Thermohaline circulation it usually depicted as a continuous flow or conveyor belt chain of currents as shown here in wikipedia.
http://en.wikipedia.org/wiki/Thermohaline_circulation
http://en.wikipedia.org/wiki/File:Thermohaline_Circulation_2.png
Note that the blue deep current surfaces in mid-Indian Ocean, which would bring deep cold water to the surface. What if the Indian ocean is in a marginally stable stratified condition and periodically over turns large cells of deep water?
That could explain such a sudden plunge in apparent heat content of the upper 700 meter layers.
There was interesting research done on fluid flows several decades ago, called “fluidics” which described fluid flow switches and analogs to transistors. One of those was a system where fluid flowed into the base of Y connection and remained attached to the wall of the Y and most of the flow passed out of only one branch of the Y. By injections of very small amounts of fluid near the point that the tube bifricates, that attached flow could be “flopped” to pass out the other branch where it would remain attached until the switching process was reversed. This formed a fluid flow bistable switch or fluidic flip flop circuit.
http://en.wikipedia.org/wiki/Fluidics
http://physics.ucsd.edu/~groisman/windows/field2.htm
http://books.google.com/books?id=3TzYnijxbo8C&pg=PA173&lpg=PA173&dq=fluidic+flip+flop&source=bl&ots=ZUxlulZGLJ&sig=Kp-Vy5YUo-smfRZ9kEVKBq1RGvQ&hl=en&ei=I9ujSpaWJpPgsQOvua2NDw&sa=X&oi=book_result&ct=result&resnum=7#v=onepage&q=fluidic%20flip%20flop&f=false
To speculate than, another possibility is that the Thermohaline circulation might be in a similar bi-stable flow situation in some locations and relatively small local disturbances (like from out flow from flood a swollen river delta, or salinity over turning ) could “switch” the flow to the other flow path.
As I understand it, the Indian Monsoons are driven by SST’s of the Indian Ocean. When it gets warm enough it “switches on” the drenching monsoon rains.
I would think it reasonable to guess, that during that Monsoon cycle, the evaporating pool of the Indian Ocean surface would change dramatically in both salinity and temperature as billions of tons of water are evaporated off the surface, and swept inland by the winds. Were there unusual monsoon conditions during those periods that had sharp down turns in Indian Ocean heat content?
Then after some time delay for transport inland, rain out, and return flow in the rivers, a large fraction of that fresh water comes gushing back into the Indian Ocean basin as muddy (high density ?) flood waters from the major rivers like the Ganges .
Would this muddy fresh water be dense enough to plow down under the sea water and like an outflow boundary in a thunderstorm system provide lifting to bump deep cold water up to the surface?
If so such a sudden drop in SST should abruptly shut off the monsoon or weaken the pending monsoon season.
It would take some historical research to see if there is any massive flooding event , or unusual monsoon cycle, during that time period, or other likely trigger event prior to and closely timed to those two plunges in SST in the Indian ocean.
As I have speculated in the past on this forum, the thermohaline circulation is also in a sense a delay line memory storage device. The water that surfaces in the Indian ocean sunk in the North Atlantic several hundred years ago (according to the current thermohaline circulation model). If the density/temperature/salinity profiles in the Indian ocean are subject to mass overturning occasionally due to some external trigger, it could significantly alter the 0-700 meter heat content if a large bolus of cold deep water were for some reason forced to the surface.
There is also a paper that questions if the traditional interpretation of the thermohaline circulation is entirely correct.
http://www.nature.com/nature/journal/v459/n7244/full/nature07979.html
(paid viewing document – the abstract looks interesting, perhaps our academic friends here on the forum can give an executive summary of it for the “masses”)
Larry
Bob Tisdale
Good popst as always.
I am trying to find out the temperatures of arctic waters (which will vary considerably according to specific location) both close to the surface and under the ice. I want to compare it with historic records. I really need them to be location specfic rather than covering a huge area. Any ideas where to look?
Thanks.
tonyb
Good work from Bob identifying differences in the different bodies of oceanic water and bringing volcanic events into the scenario too.
As I have been saying what matters for global air temperatures is the combined netted out behaviour of all the oceans at any given moment. Sometimes they all work together but more usually the various time lags mean that there is normally some offset from one or more oceans against the others.
Beyond that there is century scale variation in solar input to provide a general background trend such as that from the Little Ice Age to the recent Modern Maximum.
Then comes the chicken and egg problem as regards the interaction between air and water. My view is that the variations in the oceanic rates of energy release occur first from some feature within the oceans and the air then follows. It is mentioned in someone’s post here that El Nino causes changes in the air that then feed back more solar shortwave into the oceans but I’m doubtful on that.
When there is an EL Nino the air above does warm and as warmer air can hold more water in vapour form then at first there would be a reduction in low level cloudiness. However that is a very short lived effect. Very quickly the speed of the hydrological cycle increases with more medium and high level cloud which would more than offset the effect of the initial reduction in low cloud cover. El Nino reduces ocean heat content as Bob says.
In the process the air warms globally (as long as cool SSTs in other ocreans are not offsetting it), the equatorial air masses expand and the air circulation systems are pushed poleward. The faster hydrological cycle expels the surplus energy in the air to space faster.
Whenever ocean SSTs change (the overall net effect that is) the latitudinal position of all the global air circulation systems changes and the speed of the hydrological cycle changes to neutralise the oceanic effect over time.
The same system must also dispose of extra energy in the air alone from any other cause because the air temperatures must always move towards sea surface temperatures and never vice versa except locally and very temporarily.
“warming in the pipeline” refers to a global radiative imbalance which has not yet been relieved by warming because the heat capacity of the system is so large. It exists in the theory of AGW, but has not actually been measured because it is so small (Hansen says somewhat less than 1 W/m2). If the climate system is insensitive, though, then any radiative imbalances are fairly rapidly eliminated by temperature change.
Which brings up a point of confusion…a very sensitive climate system takes longer to equilibrate to a new temperature, but it’s time rate of change of temperature is actually larger than for an insensitive system. Let’s see if anyone here can figure out how that can be true.
NODC’s OHC data prior to 2005 is of questionable accuracy.
2005 onwards is the much more accurate ARGO data.
Note the upward trend in OHC stops in 2005. This could be due to a real effect or caused by an upward bias in the pre-2005 data not present in the ARGO data.
The estimates, adjustments and extrapolations in the OHC data pre-2005 make the surface temperature data look positively pristine.
A highly technical paper on the subject.
ftp://ftp.nodc.noaa.gov/pub/data.nodc/woa/PUBLICATIONS/grlheat08.pdf
How can anyone make a post in disparate geographic, time, instrument quality data AND still call it Science?
Re: gtrip (03:37:21)
I think you need to take a more careful look at the opportunism in play. These issues don’t divide along socialism-capitalism nor left-right lines. Here in BC the ‘socialists’ oppose the carbon tax that the right-wingers introduced (& now the right-wingers are introducing yet more taxes …yes, you heard that right – right-wingers). At the federal level in Canada, the right-wingers fear-monger about ‘Arctic sovereignty’ and international Arctic resource development conflict in the coming years (which won’t happen if the Arctic goes into the deep freeze). Capital-oriented forces are eager for Arctic resource speculation & development. The Green Party here in Canada tries to attract disgruntled fiscal-conservatives (partly because they have stiff competition from the New Democratic Party for the ‘socialist’ vote). What I am trying to say is: Don’t underestimate opportunism. People with an aim to dominate, whether politically or economically, are going to have a finger on the pulse of the general public and they won’t be abandoning common sense about opportunity.
–
Bob, if warm Indian water moved to the Pacific in a ‘bubble’ or burst in the 90s, I’ll be curious to see (in a future post) which path(s) you figure it might have taken. Politics & economics aside, there is something fundamental about nature to be learned here.
Apparently sanity prevailed at the recent World Meteorological Organization’s World Climate Conference in Geneva last week:
http://www.newscientist.com/article/dn17742-worlds-climate-could-cool-first-warm-later.html?full=true&print=true
Not a mea culpa, but definite progress in terms of climate rationality. Maybe some will rub off on some other UN activities.
BTW, the terminology seems to have transitioned to the threat of “climate variability and change”:
http://www.wmo.int/wcc3/documents/WCC-3_Statement_Ex_Summary_04-09-095PM.pdf
gtrip wrote:
“So chase your global temperatures as if there is one and feel good about your findings whether you be pro warming or anti warming or maybe just milktoast.”
gtrip, I have found the people that post on wattsupwiththat are not pro AGW, pro cooling, pro anti-AGW, or any thing else. Well, that is not totally true, they are pro-truth. They are brainstorming on this website to gain more knowledge about our incredibly complex climate system.
Another trait that most posters on this site posess is they understand how difficult it is to prove scientific theories about solar influence and our climate.
I am hazarding another guess, many of the people who post on this website would probably be here with or without the AGW hoax.
Our solar system is absolutely incredible, we should study it. And our conclusions should be based on sound science.