On Thermal Expansion & Thermal Contraction - 30

Fig. 1

Since it is nearing the end of this year, 2017, and also nearing the beginning of 2018, let's finalize the understanding of the Dredd Blog efforts to find a balanced usage of WOD in situ measurements with which to calculate thermal expansion and contraction values.

Fig. 2

In recent posts in a recent series I pointed  out that "golden" locations have been discovered and used in sea level measurement scenarios (PSMSL) and surface atmospheric measurement scenarios (GISTEMP) but not for WOD datasets.

What was missing was the "golden" for World Ocean Database measurements (WOD).

During that exercise I discovered that the Dredd Blog seven level depth system did not sync well with the WOD Thirty-Three Level depth system (Oceans: Abstract Values vs. Measured Values, 2, 3, 4, 5, 6, 7).

Fig. 3a

Fig. 3b Zones Used @ Pairs

The problem wasn't and isn't in situ measurements per se, rather it was and is that converting the 33 depth level values into 7 depth level values, or vice versa, was a clumsy exercise.

So, I changed (databases and software) to the thirty-three depth level system (the graphs at Fig. 1 and Fig. 2 show the quantity of measurements in the CTD & PFL WOD datasets at each of the 18 WOD Layers (0-17) and at each of the 33 depths (0-5500).

Another issue was that during the year I switched to using the TEOS-10 toolkit for thermal expansion calculations, which required specialized measurement usage.

The reason for this requirement is that TEOS calculations require a pair of measurements, that is, one member of the pair must be in situ T (temperature), and the other member of the pair must be in situ SP (salinity).

Fig. 4 Zones Used @ Singles

By "pair" I mean that both of those measurements are taken at the same time and same depth.

That pair requirement decreases the number of measurements that can be used to calculate the TEOS values, because the datasets have varying numbers of single measurements.

When the TEOS-10 toolkit is used those software functions generally require salinity, temperature, and depth values from the same time and depth in order to render a valid result (especially those associated with calculating thermal expansion and contraction).

Fig. 5

The difference in quantity of measurements and WOD Zones that can be used (when doing thermosteric calculations vs. calculating only temperature alone, salinity alone) can be seen by perusing Fig. 3a, Fig. 3b, and Fig. 4.

What causes that can be grasped by looking at the measurement totals in the graphic at Fig. 5.

All of those in situ measurement numbers that end in an odd number are not composed completely of pairs.

Many are single measurements of either salinity or temperature, but not both, at a given depth, thus those measurement singularities cannot be used when calculating thermosteric sea level or ocean volume changes values with the TEOS-10 toolkit.

For that matter generally, any other TEOS values which require paired in situ measurements can't be calculated with a single temperature measurement or a single salinity measurement.

As it turns out, the Zones that contain pair-measurements (Fig. 3b) end up being the "Golden 271" Zones for purposes of thermosteric calculations, while the larger numbered list of Zones (Fig. 5) can and must be used for other purposes.

NOTE: the "measurements" mentioned and counted are from the "secondary datasets" which are mean averages of the 0.9 billion in situ measurements in the primary datasets (e.g. the 59,218 "measurements" @ Layer 9 in Fig. 5 are 59,218 mean averages of data in the primary datasets ... as are all other "measurements" mentioned in this post).

In conclusion, I hope that eventually the establishment scientific community begins to look into the roots of the beginning of the misconceptions about thermal expansion hypotheses that allege but do not prove that thermal expansion is the major factor in sea level change.

The next post in this series is here, the previous post in this series is here.