Fig. 1 NOAA Thermohaline Circulation |
I. First
In today's post I want to explore a "cognitive black hole."
That cognitive black hole is the flow of heat in the oceans.
Let's explore the issue lost in the black hole by using the light of the Second Law of Thermodynamics to peer into the darkness.
II. Second
This one post is not designed to completely question or solve all the issues that may arise.
Instead, this one post is designed to question those issues that must be addressed prior to logically and reasonably moving on to another issue.
Not being one to move on, until every material issue taking place in a particular scenario is explained, I will make some comments or ask some questions that address skipped-over issues.
III. Third
The graphic at Fig. 1 is a NOAA explanation for how Thermohaline Currents
are engendered.
Concept One:
"... the heat provided by the Sun is effectively distributed throughout the top(Windows To The Universe, emphasis added). The world according to measurements requires that we do not leave out measuring 90% of that world.
few hundred meters of ocean water. However, the deeper ocean, which contains about 90% of all ocean water, does not mingle much with the surface layers ..."
Fig. 2 How deep?
"... warming (or cooling) of the deep ocean will likely occur on much longer timescales than is the case for the ocean's surface layers ... "
"Global warming will heat the deep ocean very slowly ..."
"Effects that began early during the industrial revolution in the 1800s are now being felt in the deep oceans."
Concept Two:
The second law of thermodynamics has been stated in many ways. For us,
Rudolf Clausius said it best:
Fig. 3 All the way down dood!
"Heat generally cannot flow spontaneously from a material at lower temperature to a material at higher temperature."So if you put something hot next to something cold, the hot thing won't get hotter, and the cold thing won't get colder. That's so obvious that it hardly needs a scientist to say it, we know this from our daily lives. If you put an ice-cube into your drink, the drink doesn't boil ... (Skeptical Science)
"The second law can be expressed in several ways, the simplest being that heat will naturally flow from a hotter to a colder body." - (What is the second law of thermodynamics?)
IV. Fourth
In some matters one has to "follow the money," but in this case one has to follow the
Fig. 4 Temperatures change at all depths |
That is if one wants to see if a warmer layer's "heat will naturally flow" from that hotter layer to a colder layer per the Second Law of Thermodynamics.
That would seem to be the case shown in Fig. 4.
Using the average ocean depth (3688.08 m, 12,100 ft), the 90% / 10% separation sections of the ocean's average would be 368.808m (10%) and 3319.272 (90%).
Thus, in a thermodynamic "natural flow," for every 9 degree C loss of temperature in the entire 10% warmer layer, there would be only a 1 degree C increase in the entire cooler 90% layer.
Fig. 5 |
The graph at Fig. 4 shows temperature fluctuation up and down, which is an indication that heat is either entering a layer, or leaving it, to go to another layer with a different temperature.
The thermodynamic law is that the direction of travel is from warmer ocean water to colder ocean water (warmer region -> colder region).
The graphic at Fig. 5 shows how a band of heat can move lower in the water column without violating the laws of thermodynamics.
The amount of heat (red) moving downward stays the same amount (first law of thermodynamics) as it changes the temperature of the water at the moving heat column's edges.
That is, as the temperature of the cool water (dark blue) at the bottom of the heat band (red) changes by warming, the temperature at the top of the band (red) touching the warmer surface band (cyan) drops an equal amount so that energy is conserved (the temperature changes, but the quantity of heat does not).
Since the deeper water is generally colder, then by thermodynamic law the flow is generally from shallower depths of warmer water to deeper depths of colder water.
In some cases, the average temperature of the surface will drop as an equal rise takes place in deeper cooler water to balance the equation.
Some observers have misinterpreted actual events (where surface temperature drops) as a hiatus, without having carefully measured the depths beneath the band of ocean water that dropped in temperature.
Other observers have noticed that misinterpretation:
"According to the paper, arguably, the most appropriate single variable in Earth's system that can be used to monitor global warming is ocean heat content integrated from the surface to different layers and to the bottom of the ocean."(Oceans act as a 'heat sink': No global warming ‘hiatus’). When that surface layer average temperature drops, there will have been an increase in average water temperature in the layer somewhere down below (unless the surface heat had flowed upward to cooler air above the ocean surface).
V. Fifth
The problem with the thermal expansion hypothesis is that it makes a similar mistake all too often, because in the vast majority of cases the deep cold water "heat sink" underneath is not sufficiently considered (Steric-Related Sea Level Change Estimates).
One of the papers in that link used measurements at depths from 0-750m, four of them used depths of 0-700m, and only one used 0-3000m (none of them used deep water WOD measurements >3000m, or considered the ocean as a whole).
They all also implied that the ocean surface water will stay at a fixed temperature year in and year out, rather than flowing from warmer to cooler water "naturally" (spontaneously).
They did not discuss the surface cooling at night, during rain deluges, or the flow of heat according to the laws of thermodynamics.
They assume a static bathtub model construct, and leave out the dynamics of 90% of the ocean under the water they hypothesized about.
VI. Sixth
The reality is that ocean water is in constant flux and temperatures are changing at all depths (On Thermal Expansion & Thermal Contraction, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18).
But that dynamic is all too often "below the radar."
VII. Conclusion
Graphs which clearly show these variations and changes in ocean water at all depths have been produced repeatedly on Dredd Blog (e.g. The Layered Approach To Big Water - 7).
This is another case of "I see ghosts" (The Ghost-Water Constant, 2, 3, 4, 5, 6, 7, 8).
Those ghosts are temperature ghosts this time, not relocated ocean water ghosts.
The next post in this series is here.
Great explanation, Dredd. Is the trend going to be toward a warmer ocean due to the loss of albedo in the Arctic? The thermohaline current is slowing in the Atlantic and will have some effect on both ocean and atmospheric heat distribution and possibly weather in Europe, but the cries of "mini-Ice Age" (due to the upcoming solar minimum combined with this slow-down in circulation) are a bit far-fetched, imho. What say ye?
ReplyDeleteTom
Tom,
DeleteYou wrote: "Is the trend going to be toward a warmer ocean ..."
Yes.
It has been since circa 1750.
It is just that the greatest warming is going to be in depths below where researchers are habitually looking.
That is, unless the "skim the surface" policy or tendency is changed.
With ARGO the depths can be probed automatically now (that data is stored in the WOD PFL dataset).
Remember, a change in temperature from -2C to +2C in the depths (>3000 m) is a very large warming (in terms of heat storage) even though +2C (35.6 F) is still "cold water."
The warming at those depths is more like .01 degree C over a span of time in a vast volume of water.
So, if our temperature detection equipment is not very sensitive we could miss it even tho we look for it.
And if we don't look, it will remain another form of ghost ... ghost temperature change, ghost warming ... hidden in plain sight.