Saturday, April 27, 2024

World Ocean Database Project - 5

Fig. 1 GISS Ocean Anomalies

I. Background

The GISS anomaly technique I used to prepare today's graphs applies to the atmosphere and to the ocean as well.

Those particular anomaly values go back to 1880, and end in 2024 and were displayed in the previous post of this series (Fig. 1).

The purpose of today's use of the GISS estimates combined with actual WOD in situ measurements is to compare general temperature anomalies with actual measurements to see what happens.

I am only using the ocean anomaly data, not the land or atmospheric ones.

As it turns out this technique is quite revealing when I splice in actual measurements in various ocean depths of several oceans, seas, and gulfs as shown by graphs in today's appendices.

II. Injection of World Ocean Database
(WOD) Maximum Minimum Values


The depth level maximum and minimum values for various ocean areas are detailed in the
Fig. 2 Coastal Equatorial Atlantic
WORLD OCEAN DATABASE 2018 USER’S MANUAL at Appendix 11.1 therein, at page 68.

Those max/min values WOD used to moderate submissions to their database can be injected into the GISS data stream to expand its pattern to those WOD depth levels.

A result of that technique is shown in Fig. 2 (cf. Appendix Coastal).

That is done by adding 1) the maximum valid temperature, 2) the minimum valid temperature (negative values multiplied by -1.0 to convert them to positive values) so as to derive the complete span, 3) divide that sum by 2 to derive the median, 4) then add the GISS value for that depth and year.

This is done for each depth level and year being graphed, as shown in Fig 2 using 1800-2023 as the span of years.

III. Injection of World Ocean Database
(WOD) In Situ Values

The technique in section II above is one of a "coastal" area where in situ measurements are sparse because depths are shallow.

Fig. 3 Actual In Situ
Values Change The Picture

If we move to deeper waters there are more in situ measurements in the
WOD to work with when we use the technique of injecting in situ measurements into the GISS pattern.

The graph at Fig. 3 is of the equatorial waters of the Atlantic ocean.

The pattern from the year 1880 to about the year 1900 is essentially absent of any fluctuation because there are no in situ measurements to inject into the flow pattern.

At about the year 1900 fluctuation begins because that is when researchers began to deposit in situ measurements into the WOD database.

Fig. 4 Zone In
The shallower depths have more of a departure from the median GISS values, but that departure diminishes at about the year 1960 as the temperatures measured are closer to the median (max + min divided by 2) values (which show a general increase in temperature from then until now).

Note that extracting the in situ measurements is not an easy task because an "ocean area" is a group of WOD zones (Fig. 4).

One has to decide which zones are in which ocean.

That is done by acquiring the latitude and longitude of the zone, then seeing if those coordinates are within the coordinates of the boundaries of the subject ocean.

Then one must load those values into a cumulative total, then divide that value by the number of measurements to derive the final average value (WOD Update).

IV. Closing Comments

The appendices (Sea and Gulf, Ocean, Coastal) describe which depths the different colored lines depict, as follows:


The following line colors
indicate the depths:

Sea level to 250m (red)
251m to 1000m (green)
1001m to 4000m (brown)
4001m to 5500m (orchid)
5501 to bottom (blue)

These graphs add to the reality that the ocean depth temperatures are not what they were 50-100 years ago.

Textbooks present a picture of ocean temperatures as axiomatically growing colder as the depth increased.

We now know that the warmest waters are at some of the deep depths, which causes tidal glaciers to melt deep down much faster than they melt at their surface (In Search Of Ocean Heat, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17; Antarctica 2.0, 2, 3, 4, 5, 6 [& supplements A, B, C, D, E, F], 7, 8, 9, 10, 11, 12, 13, 14, 15).

The previous post in this series is here.


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