On Thermal Expansion & Thermal Contraction - 19

Fig. 1 Trend

First, a couple of quotes relevant to today's post:

"Concerning graphs of climate change and sea level change, the truth is in the trend line, not in the facts of the seesaw / sawtooth pattern."

"Scientists have discovered that 'the present' has always existed, but some of them are not sure about 'the past' and 'the future'." (Dredd Blog quotes page).

Next, a word about Dredd Blog graphs.

The "trend," when it comes to graphs, is the direction things are going, all things considered (Fig. 1).

"Cherry-picking" is choosing a segment of the data that is not in accord with the trend.

The historical portion of graph data is composed of in situ measurements.

The portion of a graph that is either before or after the historical portion is called "then."

All graphs are composed of then + now + then (past, present, and future), or some partial combination of those three concepts of time.

Fig. 2

I say "then" in the sense that both the past and the future are calculated by using the present to calculate what is estimated to have happened previously, because we have no in situ measurements for that period of time.

The same goes for what is calculated as "what is going to happen," because we have no in situ measurements for that period of time either.

And finally, the in situ measurements that we do have, even when taken in the present, may not be robust, may not be comprehensive.

That is, there may be gaps in the data because measurements have not yet been taken at each and every location related to the issues presented in a graph.

Fig. 3 These patterns must match

That is why there is a Dredd Blog series titled "The World According To Measurements."

I have "the past" and "the now" working on the final software modules being used to shed some light on the issue of thermal expansion and contraction.

Those modules are used to experiment with, and to explore that concept.

I consider it an important issue because it has been described as "the major cause of sea level rise in the 19th and 20th centuries."

Regular readers know that I have expended a lot of time and effort researching that hypothesis, and that I do not agree with that hypothesis (On Thermal Expansion & Thermal Contraction, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18).

Fig. 4

The melting Cryosphere is the major cause of sea level rise, and fall, in terms of adding mass to the oceans.

In addition to that, "ghost water" adds to sea level rise and fall without adding to the mass of the ocean (The Ghost-Water Constant, 2, 3, 4, 5, 6, 7, 8; The Gravity of Sea Level Change, 2, 3, 4).

Thermal expansion and contraction do not add to the mass of the ocean either, however, they do contribute steric thermal sea level changes because they increase and decrease the ocean volume intermittently.

But not in a major quantity, that is, thermal expansion and contraction are minor players in sea level changes that equate to trends.

Today's graphs include historical measurements, and projections into the past, but do not yet include future projections.

That is next on the agenda.

The new modules do not use the global ocean volume value (1.37 x 10⁹ km³) because WOD measurements are not available for every zone on the planet.

So, I use the volume value of each zone used in each layer used.

Layers are made up of up to 36 zones (if there are no measurements in a zone, or the zone is land only, i.e. no ocean water, it is excluded).

The zone volume is calculated (a zone's volume gets smaller the further away from the Equator, and the closer to the polar region it is), then added up to become that layer's volume of ocean water.

This is more accurate than using the entire ocean volume, since some zones and even one layer at Antarctica (layer 17) is not used.

The graphs at Fig. 2 and Fig. 4 offer patterns for comparison, so readers can see that the thermal expansion hypothesis does not pass muster.

Sea level rise patterns compare to atmospheric and land surface temperatures, while the thermal expansion pattern matches ocean water and salinity patterns.

The addition of the TEOS-10 library is a must for these types of situations:

The more prominent advantages of TEOS-­‐‐10 compared with EOS-­‐‐80 are:

• For the first time the influence of the spatially varying composition of seawater is systematically taken into account through the use of Absolute Salinity S_A. In the open ocean, this has a non-­‐‐trivial effect on the horizontal density gradient, and thereby on ocean velocities and “heat” transports calculated via the “thermal wind” relation.

• The new salinity variable, Absolute Salinity S_A, is measured in SI units (e.g. g kg −1 ).

• The Gibbs function approach of TEOS-­‐‐10 allows the calculation of internal energy, entropy, enthalpy, potential enthalpy and the chemical potentials of seawater as well as the freezing temperature, and the latent heats of melting and of evaporation. These quantities were not available from EOS-­‐‐80 but are essential for the accurate accounting of “heat” in the ocean and for the consistent and accurate treatment of air-­‐‐sea and ice-­‐‐sea heat fluxes in coupled climate models.

• In particular, Conservative Temperature Θ accurately represents the “heat content” per unit mass of seawater, and is to be used in place of potential temperature θ in oceanography.

• The thermodynamic quantities available from TEOS-­‐‐10 are totally consistent with each other, while this was not the case with EOS-­‐‐80.

• A single algorithm for seawater density (the 75-­‐‐term computationally-­‐‐efficient expression v SA ,Θ, p ) can now be used for ocean modelling, for observational oceanography, and for theoretical studies. By contrast, for the past 30 years we have used different algorithms for density in ocean modelling and in observational oceanography and inverse modelling.

(Getting Started with TEOS-10, PDF). Good stuff.

Anyone know the basic argument supporting the hypothesis "the major cause of sea level rise in the 19th and 20th centuries" is thermal expansion?

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