Oceans: Abstract Values vs. Measured Values - 3

Fig. 1

This series is about one question: "So, how does one go about finding the Golden World Ocean Database (WOD) measurements the same way that scientist Bruce C. Douglas did with PSMSL tide gauge station records?"

Bruce C. Douglas (hereinafter 'Douglas') carefully and professionally boiled it down to what Dredd Blog has called "the Golden 23 tide gauge stations" (Golden 23 Zones Meet TEOS-10).

Douglas had to do that, pick the golden 23, from over a thousand tide gauge stations spread all around the globe.


As the link to the WOD page shows, there are 648 individual WOD Zones in 18 ten degree latitude bands around the globe.

Fig. 2

So, it would seem, at first blush, that the current problem is easier because 648 is less than over a thousand.

What makes the current problem more difficult is that Douglas only had to deal with one depth, which is zero because sea level at tide gauge stations is measured at the surface.

To solve the WOD measurement selection problem that is now confronting us, we have to also consider measurements of temperature and salinity at 33 different depths in each of those hundreds of WOD Zones.

Fig. 3ARGO float distribution

That is just one issue in this multi-issue problem.

Another issue, besides the "what latitude and longitude locations make a balanced measurement dataset," is the "at what depths should the measurements be taken" issue.

That is a particularly difficult problem because even the ARGO automated measuring drones (Fig. 3) only go down to about 2,000 meters, which is over a thousand meters short of the median ocean depth of about 3,682.2 meters.

The ARGO data is in the WOD PFL dataset which I use consistently, along with the CTD dataset.

Fig. 4a

Fig. 4b

Fig. 4c

Fig. 4d

As was discussed in the first two posts of this series, I am in the process of developing a software module to carry the largest portion of the burden of solving the problem initially.

Version 1.4 of that module generated the graphs shown in today's post.

The first problem was to have a gauge with which we could compare to measurements in the WOD.

That initial tool was described in the first post of this series (Oceans: Abstract Values vs. Measured Values).

That tool uses all measurements in the WOD (all 18 layers of zones) as well as using six specified layers I am calling "the Golden Six Layers" for comparisons.

The comparisons involve comparing the results of using those eighteen layers with the results of using only the six layers, and then comparing those two results with the results generated by the abstract mathematical projection (Oceans: Abstract Values vs. Measured Values - 2).

The abstract version is a mathematical abstraction based on the WOD maximum minimum values for each of the 30 ocean basins around the world (for both salinity and temperature).

This backdrop will expose datasets of measurements as being too concentrated in terms of latitude & longitude, as well as too concentrated at habitual depth levels.


I am using the software module (version 1.4) in an effort to choose the best layers.

So far, as I said in previous posts, six are being used.

Check out the graphs for an idea of how it is progressing.

Dr. Mitrovica reveals some previously unused science to clear the air of some common oceanography ignorance (video below).

The previous post in this series is here.

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