 |
| Fig. 1 deg. C |
The "thermal expansion is the cause of most sea level change" myth is persistent but it is still not accurate.
So, today I am showing calculations of thermal expansion and contraction using the World Ocean Database (WOD) maximum temperatures at the temperature from which calculations can be made (see Appendix 11.1 in the WOD manual).
Those temperatures are well above the actual temperatures of the seawater in the oceans at this time.
The example Fig. 1, which shows the maximum temperature values of seawater is taken from the WOD Manual at Appendix 11.1 (N. Atlantic).
Meanwhile, the graph at Fig. 2 shows actual in situ temperatures in the N. Atlantic in recent years.
Those in situ N. Atlantic temperatures at this time are ~20 degrees C. lower than the maximum shown in Fig. 1 for that ocean area.
That Fig. 2 graph is located in the Dredd Blog post On Thermal Expansion & Thermal Contraction - 48 at Appendix Arctic/Atlantic.
I am using the maximum temperatures shown in the WOD Manual to show that thermal expansion calculated at the maximum temperatures is orders of magnitude too small to be considered a significant factor in sea level change.
 |
| Fig. 2 N. Atlantic Seawater Temperatures |
Today's appendices overwhelmingly support that fact and also falsify the hypothesis currently spread by those who only scratch the surface of the oceans.
As you can see from the Maximum-Minimum Table at Fig. 1 some of the values are repeated for several depth levels.
To alleviate that repetition I used the GISS ocean anomaly figures to distinguish temperature variation by small GISS values.
Those GISS variations I used are:
{1950,-0.18},{1951,-0.06},{1952,0.01},{1953,0.07},{1954,-0.14},
{1955,-0.14},{1956,-0.2},{1957,0.05},{1958,0.07},{1959,0.03},
{1960,-0.02},{1961,0.06},{1962,0.04},{1963,0.07},{1964,-0.2},
{1965,-0.1},{1966,-0.05},{1967,-0.02},{1968,-0.08},{1969,0.07},
{1970,0.03},{1971,-0.09},{1972,0.01},{1973,0.16},{1974,-0.09},
{1975,-0.02},{1976,-0.11},{1977,0.17},{1978,0.06},{1979,0.16},
{1980,0.27},{1981,0.33},{1982,0.13},{1983,0.31},{1984,0.16},
{1985,0.12},{1986,0.18},{1987,0.33},{1988,0.41},{1989,0.28},
{1990,0.44},{1991,0.41},{1992,0.22},{1993,0.24},{1994,0.31},
{1995,0.45},{1996,0.34},{1997,0.47},{1998,0.62},{1999,0.4},
{2000,0.4},{2001,0.54},{2002,0.63},{2003,0.61},{2004,0.54},
{2005,0.67},{2006,0.62},{2007,0.65},{2008,0.52},{2009,0.64},
{2010,0.7},{2011,0.57},{2012,0.62},{2013,0.65},{2014,0.73},
{2015,0.87},{2016,1.0},{2017,0.89},{2018,0.85},{2019,0.98},
{2020,0.985},{2021,0.99},{2022,1.0},{2023,1.5}
};
(Fig. 3 C++ struct for GISS anomalies). The conclusions show that thermal expansion and contraction reality is based upon temperature change, not just temperature alone:
Ocean Area count: 12; Years averaged: 72 (max)
Total thermal expansion/contraction: 13.91 mm
Average per ocean area: 1.16 mm
Average per year: 0.19 mm
Percent of current 3.6mm sea level rise per year: 5.37 %
For example, an ocean area with a temperature of 35 deg. C. (95 deg. F.) will have less thermal expansion or contraction change than one with a temperature of 25 deg C. (77 deg. F.) if the former stays at its same temperature while the latter's temperature increases or decreases by only 1 deg. C. (33.8 deg. F.).
Really, a really hot sea water temperature of 95 deg. C. will have no thermal expansion or contraction as long as it remains at that temperature.
Also by the same token, a seawater temperature of 25 deg. C. (77 deg. F.) which rises to 30 deg. C. (86 deg. F.) will have thermal expansion, then it will change into thermal contraction if the temperature drops back to 30 deg. C. (86 deg. F.).
Thermal expansion and contraction is based upon temperature change, not just temperature alone.
Today's appendices show the calculations on seawater when there is small temperature change (change of mostly less than 1 degree C.).
That quantity of change is the global GISStemp ocean surface change which is primarily less than 1 deg. C. (Fig. 3) which in this case has a span from the year 1950 to the year 2023.
 |
| Fig. 4 Ocean Area Locations |
The appendices are HTML tables (Arctic, Equatorial Atlantic, Equatorial Indian, Equatorial Pacific, Mediterranean, North Atlantic, North Indian, North Pacific, South Atlantic, Southern, South Indian, South Pacific).
[UPDATING APPENDICES ... errors ... what a 'coincidence?' ... world software collapse ... no, it was the 'Coastal' ocean areas; they have been removed]
Graphic depictions of ocean area locations, which are the major ones contained in the list of ocean areas used in this post, are shown at Fig. 4.
Closing Comments
The unquestionable major cause of sea level change is glacial melt (Hot, Warm, & Cold Thermal Facts: Tidewater-Glaciers - 9).
The previous post in this series is here.