|Fig. 1 El Nino Formation Area|
Have you formed an opinion about the hypothesis that "thermal expansion caused MOST sea level rise in the past century"?
These World Ocean Database (WOD) files have further convinced me that the thermal expansion hypothesis is clearly falsified.
Today's graphs and calculations concern three zones off the west coast of South America where another mystery ("El Nino") tends to form.
|Fig. 2 Average Changes in Temperature|
For example, Fig. 1 and Fig. 2 concern the WOD Zone that is, of the three we consider today, closest to the coast.
It is zone 7009 which has the Equator as its southern boundary.
Yet, as Fig. 2 indicates, the data show a slight decrease in temperature over a 39 yr. span of time.
Remember that my argument is about what caused the MOST sea level rise over the past century, which I argue was certainly not thermal expansion.
The graph at Fig. 1 shows that this WOD Zone 7009 shows no indication of a robust warming in the 6 depth levels.
The deepest level (>3000m), which generally would be colder, had no data to include during this time frame.
The zone just west of 7009 is WOD Zone 7010 (Fig. 3, Fig. 4).
Those two graphics show a net increase of 2.4 deg. C over 33 years, but interestingly, from the surface level on down to 200m the data averages show a slight net cooling (in terms of degrees of ups and downs).
This "thermal expansion caused most sea level rise" does not seem to have support in the vast amount of evidence available.
The next WOD Zone for today's post, zone 7011, is next to and just west of zone 7010.
Again, all of these three zones have the Equator as their southern boundary, with 10 deg. N. Latitude as their northern boundary.
We are in warm water country here folks (El Nino land), where the thermal expansion hypothesis should get solid backing.
Yet, it is strikingly like the other areas we have recently considered (The Extinction of Robust Sea Ports - 7, Humble Oil-Qaeda, Hard Times2 In New York Town, Zone In On Sea Level Change - 3).
So, let's review the thinking, or lack thereof, that led The Warming Commentariat astray into thermal expansion land:
With recently improved instrumental accuracy, the change in the heat content(Ocean Science, 6, 179–184, 2010, emphasis added). That is just plain wrong, and it is also a lazy approach to scientific observation IMO (they argue that they can tell what the temperature 10,000 feet below is by what the temperature is at the surface; e.g. WOD Zone 7715 shows a surface temperature below 0 deg. C, while the subsurface temperatures are above 0 deg. C; other zones show the opposite: surface temperatures above 0 deg. C with some subsurface temperatures below 0 deg. C).
of the oceans and the corresponding contribution to the change of the sea level can be determined from in situ measurements of temperature variation with depth. Nevertheless, it would be favourable if the same changes could be evaluated from just the sea surface temperatures because the past record could then be reconstructed and future scenarios explored. Using a single column model we show that the average change in the heat content of the oceans and the corresponding contribution to a global change in the sea level can be evaluated from the past sea surface temperatures.
However, the data show that the temperature at all levels can and does change in a chaotic way, not in a mathematical, uniform, and synchronized way.
Thankfully, subsequent consideration of more than just the surface (we are not talking about skiing on a lake folks) is more robust:
"On the basis of the GRACE data, we conclude that most of the change inRemember the story of the bank robber, who when asked why she robbed banks, replied : "That is where the money is."
ocean mass is caused by the melting of polar ice sheets and mountain glaciers." Nature, GeoScience
"Comparing the two over the seven year period this study looked at, the authors found that meltwater from glaciers and ice sheets contributed more to sea level rise than thermal expansion" - Carbon Brief
Like her, when we consider net thermal expansion or contraction of the ocean, we must go where most of the water is and measure it there (clue: most of it is below the surface).
Doing that at the Equator (where the warmest water would be expected, along with resulting highest thermal expansion caused sea level rise) to test the "thermal expansion is the cause of MOST sea level rise" hypotheses, we find the hypothesis wanting (see Fig. 7 & Fig. 8 below).
Well, that is it for today.
Let me know if you notice any mistakes.
The next post in this series is here, the previous post in this series is here.
|Fig. 7 Equatorial Sea Level|
|Fig. 8 In Warm El Nino Area Waters|