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| Photons on The Move |
I. No Temperature Change
Means No Thermal Dynamics
The appendix (singular, not plural) to today's post contains all of the in situ measurements contained in the WOD datasets for the 33 depth levels within the years 1950 thru 2023 (all averaged).
They are from all ocean areas and have been averaged by year and depth to make the demonstration of proper calculation of thermal expansion and contraction the main focus (over 55 thousand averages made from ~5.5 billion WOD records).
Hopefully, this post will make it easier for others to properly calculate thermal expansion and contraction.
II. The One Appendix
The first year in The One Appendix illustrates the point that where there is no temperature change there is no thermosteric change in the volume of the seawater at the depth level shown.
The formula used is the familiar V = V0 * (1.0 + (β * DT) ) where:
V = V0(1.0 + β ΔT)
V means new thermosteric volume
V0 means original depth-level volume
β means thermal expansion coefficient
ΔT means change in temperature (T1 - T0)
I.E. "DT - delta T" (difference in temp)
In the HTML table of the appendix, at the year '1900', depth level 'L1', those values are:
(see the updated appendix)
year 1900
V = V0(1.0 + tec * (temp - prev. temp))
V = 4367.75(1.0 + 0.000113784 * (5.82829 - 5.82829))
V = 4367.75(1.0 + 0.000113784 * (0.0))
V = 4367.75(1.0 + 0.0)
V = 4367.75
vol change = V-V0
vol change = 4367.75 - 4367.75
vol change = 0.0
The thermal expansion/contraction value is zero because there was no temperature change.
III. Things Have Changed
Thermal things change with the new year 1901 because the temperature did change:
(see the updated appendix)
year 1901
V = V0(1.0 + tec * (temp - prev. temp))
V = 4367.75(1.0 + 0.000173972 * (10.9625 - 5.82829))
V = 4367.75(1.0 + 0.000173972 * (5.13421))
V = 4367.75(1.0 + 0.000893209)
V = 4367.75(1.000893209)
V = 4371.651312658
vol change cu km = 4371.651312658 - 4367.75
vol change = 3.901312658 ÷ 361.841 (tsSlc mm per cu km)
thermal expansion mm = 3.901312658 ÷ 361.841
thermal expansion = 0.010782 mm
[NOTE: there will be a small variation in values
due to number of digits, salinity change, rounding
calculator settings, etc.]
These calculations can be redone for any year using the HTML table in The One Appendix.
IV. Closing Comments
As photons move from warmer surface areas down into cooler ones, temperature changes take place in the form of both expansion and contraction. as shown by today's HTML table in The One Appendix.
The next post in this series is here, the previous post in this series is here.