|Fig. 1a Annual steric volume|
I. Thermal Expansion Formula
Volume is "The amount of 3-dimensional space an object occupies" (Math is fun).
Scientists calculate that the ocean contains some 1.37 x 109 km3 of water (1,370,000,000 cu km).
If we have some sufficient source of recorded measurements of temperature and salinity, we can use that data, along with the formula V1 = V0(1 + β ΔT) to calculate thermal expansion and contraction of the entire ocean (i.e. volume change).
II. World Ocean Database
We do have that "sufficient source of recorded measurements of temperature and salinity" known as The World Ocean Database (WOD).
|Fig. 1b Annual steric volume change|
That source also has other data associated with the temperature and salinity, such as the depth, zone location, and date of the measurements.
Today's graphs were made from WOD data which I downloaded from that location (I use only the CTD and PFL datasets in the WOD).
The quantity of those measurements totals to about 0.97 billion (~970,000,000), but a small amount of under 5% are excluded due to error flags.
|Fig. 1c Temperature/Salinity coefficient table|
At it turned out, converting the format was by far the most difficult task out of the many software tasks I had to accomplish in this project.
III. Pumping The WOD Data Through The Formula
Next, in order to generate the CSV files with which to produce the steric, thermal expansion/contraction graphs shown at Fig. 1a and Fig. 1b, the software accesses the relevant SQL Server's tables, in sequential order (year to year), averages them, and finally prints out columns of data.
The purpose for that is to generate a mean average for each year for which there is data.
The range capacity of the software module is 1800 - 2100, or 300 years.
The software module records the mean temperature and salinity of the water, at all depths, and combines the hundreds of millions of measurements into annual averages for temperature and salinity.
V1 = V0(1 + β ΔT)
The ocean volume value 1.37 x 109 km3 is represented by V0; the mean average temperature and change in temperature from one year to the next is represented by ΔT; which is nothing more than subtracting one year's temperature value from another (ΔT = T0 - T1); and the symbol β represents the salinity/temperature coefficient (see Fig. 1c).
And finally, the resulting volume for each year is represented by V1.
The resulting volume change for the entire ocean over the 50 year span of time was an increase of about 12,210 km3 (about 244 km3 per yr).
That is the very small mean-average steric, thermal-expansion volume that was generated using the CTD/PFL WOD measurements.
IV. Sea Level Rise During The Fifty Years
Another "sufficient source of recorded measurements" comes from the Permanent Service for Mean Sea Level (PSMSL).
|Fig. 3a Temperature & Salinity|
This is tide gauge station data taken at the surface on coastlines around the world.
It is in a much easier format to load into the SQL system, requiring little to no conversion, compared to the WOD data.
It covers a much longer time frame too.
However, since today's graphs are generated from combined WOD and PSMSL data, only data for the past half century are used.
That is because, in that time frame, there is a match year by year for both WOD and PSMSL data.
That combo is required to determine, primarily, whether or not thermal expansion is shown to be a major player in sea level change.
|Fig. 3b Temperature & Salinity|
Mean sea level is deceptive unless one also considers that it is a median, meaning there are much higher and much lower values that go into a mean average.
For example, the highest sea level rise in that mean was 1216.25mm or 3.99032 ft., and the lowest sea level fall was 1096.33mm, or 3.59688 ft. (Permanent Service For Mean Sea Level).
|Fig. 4a Temperature changes|
Together, that is a 1216.25 + 1096.33 = 2312.58 mm (7.5872 ft) variation between high and low regional tide gauge station recorded sea levels (ibid).
Comparing steric, thermal expansion calculations with tide gauge station sea level records indicates that we have been wrong to say that "thermal expansion has been the main cause of sea level rise in the 19th and 20th centuries" (compare Fig. 1a, Fig. 1b with Fig. 2a, Fig. 2b, and see Fig. 1 here).
That assertion is generally made without using available data for depths below 3000m (Steric-Related Sea Level Change Estimates).
|Fig. 4b Temperature|
That, even though the waters at the deeper levels below 3,000m are more sensitive to temperature changes:
"Water ... at greater depth ... expands [and contracts] more for a given heat input ..."(IPCC, see also Fig. 3, Fig. 4 here).
V. Change In Temperature-Salinity Patterns
The combined values of temperature & salinity per annum, mathematically forged into a mean average, have a pattern that looks far more similar to the thermal expansion and contraction patterns than the sea level change patterns do (compare Fig. 1a & Fig. 1b with Fig. 3a & Fig. 3b).
|Fig. 5a Salinity|
That is, those patterns look more like one another than they look like the sea level change patterns in Fig. 2a & Fig. 2b.
Even separately, the non-combined, individual temperature and individual salinity patterns are more akin to the steric, thermal volume change patterns than they are to the sea level change patterns (compare Fig. 1a & Fig. 1b with Fig. 4a, Fig. 4b and Fig. 5a, Fig. 5b).
|Fig. 5b Salinity changes|
VI. Faith And Trust
Our knowledge is more sound the more it is based on actual measurements, which are a type of observation.
Seeing sea level rise or fall with our eyes is an observation, but the measurements by equipment that are extensions of our senses are essential to a solid foundation of knowledge.
We don't often reflect upon the reality that our "knowledge" is either faith based or trust based, which fundamentally constitutes nothing more than the essence of "belief".(The Pillars of Knowledge: Faith and Trust?). It would seem that measurements are a substantial type of knowledge.
Since the secular and non-secular worlds are supposed to be utterly different from one another, for the secular realm such as science, let's call that belief "trust", and for the non-secular realm such as religion, let's call that belief "faith".
Whatever words we use, the essence of "belief" boils down to a dependence on other people, a belief in what other people write or say they know, as the real basis for what we call "our knowledge".
There is a substantial amount of discourse and debate, in some circles, about the impact that this reality should or should not have on us ...
The measurements are available to us, so Dredd Blog adds a bit of verification to the equation, which makes knowledge more robust.
We can hope that the ignorance of denial, now pulling off an ignorance coup, does not snuff out the world according to measurements.
If it does, then the rape of the minds of people using "alternate facts" is just around the bend.
That will eventually produce another increase in the form of mental illness called social dementia (Etiology of Social Dementia, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16).
The previous post in this series is here.