Tuesday, October 17, 2017

On Thermal Expansion & Thermal Contraction - 26

Fig. 1a First graph of this series
Fig. 1b Thermal Expansion
Today, let's look at thermal expansion and contraction at each depth level.

But first, let's remember that all "water contracts (decreases in volume) when heated."

What ??!!??

That is just as true as the most oft quoted statement concerning the thermosteric dynamics of water, which is: "water expands (increases in volume) when heated."

The ghost dynamic in these statements is that whether thermal expansion or thermal contraction takes place in any case depends on the in situ temperature of the water at the time when the hotness or coldness is applied to that water.

Regular readers know that this series started by pointing out that thermal expansion is not the only "thermal" in town (never forget thermal contraction).

The graphs at Fig. 1a and Fig. 1b  show both of the thermal dynamic players in the game.
Fig. 2

The gist of what is portrayed in those graphs is that there is both thermal expansion and thermal contraction (when water is heated or when water is cooled it expands (increases in volume) or it contracts (decreases in volume) depending on the in situ temperature when that warming or cooling takes place.

Fig. 3
Note that those graphs were done before I discovered TEOS-10, a toolkit developed by scientific organizations (Thermodynamic Equation of SeaWater 2010).
Fig. 4

TEOS-10 is a toolkit that makes calculating and graphing thermosteric volume change (thermal expansion & contraction) more accurate, meaningful, and certainly more professional in terms of coherency and consistency.
Fig. 5

The other graphs in today's post (Fig. 2 thru Fig. 9) show actual (not hypothetical) thermal expansion and contraction at various depths using TEOS-10 values (e.g. SA, CT, and P) that are calculated and computed from in situ practical salinity, temperature, and depth measurements stored in the World Ocean Database.
Fig. 6

Fig. 7
In other words, the salinity, temperature, and depth measurements involved are real measurements taken by real scientists at work in "the field."
Fig. 8

I think that the real graphs of the real situation at the various depths of the real oceans of the world support and validate the hypothetical assertions made by Dredd Blog over the years and also in Fig. 1a and Fig. 1b.

Who in their right mind is going to deny the existence of both thermal expansion and thermal contraction in terms of thermodynamic reality?

After all, any and all measurements in the CTD and PFL datasets of the World Ocean Database (about a billion) were used to produce graphs at Fig. 2 thru Fig. 9.

Now that we have been brave enough to admit the existence of thermal contraction, we can consider the Second Law of Thermodynamics.

I mean that we can do so at least in the sense of the movement of heat in the oceans (which has one and only one direction) which is from warm to cold (NASA, Univ. of Winnipeg).

The big take home from this is that heat in the ocean is always on the move spontaneously when the lawful conditions arise.

That movement is shown in the graphs as upward and downward lines of expansion and contraction while the flow of time moves horizontally.

I want us to also remember that this flow can reverse direction under certain lawful conditions.

Fig. 9
For example, when the water below is colder than the water above, the heat will spontaneously tend to move downward, but when that water above later becomes cooler than the water below, the warmth will move upwards rather than downwards.

By downward and upward, I am in reference to to the depth level.

We see that happening in these graphs too.

So my fellow citizen scientists, let's all remember that "the ice of Greenland and Antarctica is seriously melting."

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

The ice is seriously melting ... (Dr. Eric Rignot) ...


  1. Have you seen this, Dredd?

    Oceans Can Rise in Sudden Bursts

    Fossilized corals off Texas show that in the past, sea level rose several meters in just decades, probably due to collapsing glaciers


    [keep up the good work!]

    1. Tom,

      No, I had not seen that article.

      (I had written about "meltwater pulse 1C" here a couple of years back).

      Anyway, great link. Thanks.

      I think it is a very relevant topic, and we are ripe for such an event IMO.