|Fig. 1 World Ocean Database (WOD) Layers|
Today, I am following up on the essence of a previous Dredd Blog Post series concerning the "fingerprints" and "DNA" of sea level change (SLC).
The sea level fingerprint analogy is not primarily focused on the attributes of sea water itself.
So, the focus in this series is on the definitive natural attributes (dna) rather than the "fingerprints" because "fingerprints" only applies to sea levels, not primarily to sea water's definitive natural attributes.
I am binding the "DNA" concept with the TEOS/Gibbs robust concept of Conservative Temperature (CT) as it is found in the eighteen layers of the World Ocean Database (WOD) scheme of global "zones" (Fig. 1).
II. Why Conservative Temperature?
|Fig. 2 Conservative Temperature|
is in thermodynamic proportion to
Ocean Heat Content (hO)
Potential Enthalpy is an indicator of thermodynamic attributes in sea water, such as OHC (Patterns: Conservative Temperature & Potential Enthalpy, 2, 3).
OHC currently is a hot topic with both Oceanographers and Climate Scientists.
|WOD Layer 0|
|WOD Layer 1|
|WOD Layer 2|
|WOD Layer 3|
|WOD Layer 4|
|WOD Layer 5|
|WOD Layer 6|
|WOD Layer 7|
|WOD Layer 8|
|WOD Layer 9|
|WOD Layer 10|
|WOD Layer 11|
|WOD Layer 12|
|WOD Layer 13|
|WOD Layer 14|
|WOD Layer 15|
|WOD Layer 16|
In other words these graphs of CT have the DNA pattern of the heat intake and distribution of atmospheric heat entering the ocean layers of the globe (Fig. 1).
But a caveat to remember is that these graphs are offspring of the world according to measurements (The World According To Measurements, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21).
Our science in general is only as robust as our in situ measurements and our bona fide observations.
These graphs are the result of processing billions of in situ measurements, then processing them with the TEOS-10 toolbox, which is a product of one of the more robust American scientists:
Some may wonder why it [the TEOS-10 toolkit] is called the "Gibbs-SeaWater (GSW) Oceanographic Toolbox", so, let me explain.(The World According To Measurements - 12). That said, notice that the graphs go back over a century, about 119 years to be more exact, to a time when collecting temperature, salinity, and depth measurements was not as robust as it currently is.
The formulas encapsulated in the TEOS-10 software come originally from the mind of an American scientist:
"Willard Gibbs was a mathematical physicist who made enormous contributions to science: he founded modern statistical mechanics, he founded chemical thermodynamics, and he invented vector analysis."(J. Willard Gibbs). The Europeans also speak well of him:
"J. Willard Gibbs, in full Josiah Willard Gibbs, (born February 11, 1839, New Haven, Connecticut, U.S.—died April 28, 1903, New Haven), theoretical physicist and chemist who was one of the greatest scientists in the United States in the 19th century. His application of thermodynamic theory converted a large part of physical chemistry from an empirical into a deductive science."(Encyclopedia Brittanica, emphasis added). Thus, the scientific work that Gibbs did is encapsulated in the software that Dredd Blog uses to analyze ocean water thermodynamics.
The better the scientific tools the better the science.
But by and large, the practices were adequate enough to determine ocean temperature, depth, latitude, longitude, and conductivity (salinity) to a reasonable degree.
Some modern techniques (XBT anyone?) for example had some problematic episodes (I don't use XBT data).
The WOD data can be selected in a way that results in a database that is all we need in order to use the most robust thermodynamic algorithms available, which is the Thermodynamic Equation Of Seawater - 2010 (TEOS-10).
III. The Components
The raw components of the CT DNA are three simple lines composed of the CT line, the high CT path, and the low CT path (see the graphs labeled "WOD Layer 0" - "WOD Layer 16").
Those components are enhanced by a blue fill-in that glues the visual concept together so as to enhance the picture of the span and scope of the thermodynamic flux taking place (see the graphs further down in this post labeled "CT DNA Layer 0" - "CT DNA Layer 16").
This exercise is meant to facilitate the visualization of the fundamental dynamics of ocean heat content and ocean heat flux over a robust span of time in any selected location.
The "WOD Zone" is the fundamental granularity (Fig. 1).
After all, that is how in situ measurements have been stored in the World Ocean Database since before most of us were even born.
I think that the WOD storage methodology is a cool way of handling massive amounts of measurements.
IV. Robust Granularity
The WOD documentation (see introduction and user's manual) details a thirty-three depth-level configuration.
That is considerably more granularity than the five levels of the pelagic biome that can still be useful.
The WOD granularity is important because TEOS calculations can be made using "slices" of the ocean while calculating CT and other TEOS values.
It is better to calculate using in situ measurements from thirty-three depth level slices, then combine them AFTER CT has been established for each slice.
The remaining five pelagic composites made from the thirty-three WOD slices are useful for determining "where to dig" for further gold.
As regular readers know, I have done that in various and sundry ways using the WOD data in various and sundry WOD Zones; thereby I have discovered that the laws of thermodynamics are alive and well in the ocean deeps.
V. Laws of Thermodynamics
|CT DNA Layer 0|
|CT DNA Layer 1|
|CT DNA Layer 2|
|CT DNA Layer 3|
|CT DNA Layer 4|
|CT DNA Layer 5|
|CT DNA Layer 6|
|CT DNA Layer 7|
|CT DNA Layer 8|
|CT DNA Layer 9|
|CT DNA Layer 10|
|CT DNA Layer 11|
|CT DNA Layer 12|
|CT DNA Layer 13|
|CT DNA Layer 14|
|CT DNA Layer 15|
|CT DNA Layer 16|
I rambled on about that issue in a series or two (The Ghost Plumes, 2, 3, 4, 5, 6, 7; The Ghost Photons, 2, 3).
It is interesting that at the mole granularity level or at the photon granularity level, the pattern in graphs is the same as the CT DNA level (In Search Of Ocean Heat, 2, 3, 4, 5).
The simple reality is that CT can be used to get the OHC and OHF picture.
Folks, I think "we got game" in the TEOS-10 toolbox and that we owe a depth of gratitude to Gibbs and those who have deciphered his formulas into useful algorithms in the extremely useful TEOS-10 toolbox (e.g. Potential Enthalpy: A Conservative Oceanic Variable for Evaluating Heat Content and Heat Fluxes, McDougal 2003, pp. 945-46; cf. TEOS-10 gsw_CT_from_pt).
VI. Upcoming Visual
As I wrote above, the graphs today combine all in situ measurements from 33 depth levels into one mean average graph for each of 17 WOD layers (0-16, 17 is all land no water).
As a result these graphs show OHC and OHF latitude band by latitude band.
The "weakness" is that they don't show independent pictures of the differences at multiple depths.
It is as if the ocean has only one depth.
In the past I have done graphs that do show individual depths:
|0, 1, 2, 15, & 16||A-One|
|3, 4, & 5||A-Two|
|6, 7, & 8||A-Three|
|9, 10, & 11||A-Four|
|12, 13, & 14||A-Five|
However, those graphs show only the usual one graph-line per depth-level.
So, in the next post of this series will do the CT DNA version of those graphs at the five pelagic depths.
VII. Closing Comments
The exercise when one is in search of ocean heat is to find out where it comes from, how it travels through the sea water, and where it is going.
This requires a source of data (World Ocean Database Profiles the Ocean).
An article in a climate change oriented publication put it this way:
"Scientists predicted in the 1980s that a key fingerprint of anthropogenic climate change would be found in the ocean. If they were correct that increases in greenhouse gases were changing how much heat was coming into the system, then the component with the biggest heat capacity, the oceans, is where most of that heat would end up."
"We have now had almost two decades of attempts to characterize this change, but the path to confirming those predictions has been anything but smooth …" (The long story of constraining ocean heat content).
Some of the rough going has been because of instrument failure (XBT Corrections).
Some of the rough has been the result of using "Potential Temperature" instead of "Conservative Temperature" as a variable in computer models according to scientific teams:
"The quest in this work is to derive a variable that is conservative, independent of adiabatic changes in pressure, and whose conservation equation is the oceanic version of the first law of thermodynamics. That is, we seek a variable whose advection and diffusion can be interpreted as the advection and diffusion of 'heat.' In other words, we seek to answer the question, 'what is heat' in the ocean? The variable that is currently used for this purpose in ocean models is potential temperature referenced to the sea surface, θ, but it does not accurately represent the conservation of heat because of (i) the variation of specific heat with salinity and (ii) the dependence of the total differential of enthalpy on variations of salinity."
(McDougal 2003, emphasis added).
I had a conversation some time back with a software programmer who works on computer models.
I asked whether or not that team used the TEOS-10 toolbox or were going to.
The answer was "slowly" so I translated that as "not yet."
The current standard for oceanography in terms of the thermodynamics of sea water is TEOS-10:
"This site is the official source of information about the Thermodynamic Equation Of Seawater - 2010 (TEOS-10), and the way in which it should be used."
"TEOS-10 is based on a Gibbs function formulation from which all thermodynamic properties of seawater (density, enthalpy, entropy sound speed, etc.) can be derived in a thermodynamically consistent manner. TEOS-10 was adopted by the Intergovernmental Oceanographic Commission at its 25th Assembly in June 2009 to replace EOS-80 as the official description of seawater and ice properties in marine science" (Thermodynamic Equation Of Seawater - 2010).
I dare say that we are beyond the time to use that scientific standard.
It is a way to remove rough going and replace it with smoother sailing.
The next post in this series is here.