Ocean temperature reconstructed over the last 700,000 years

UNIVERSITY OF BERN

Research News

IMAGE
IMAGE: AN ICE SAMPLE FROM AN ANTARCTIC ICE CORE. view more CREDIT: DANIEL BAGGENSTOS

Bern’s ice core researchers were already able to demonstrate in 2008 how the concentration of CO2 in the atmosphere has changed over the past 800,000 years. Now, using the same ice core from the Antarctic, the group led by Bernese climate researcher Hubertus Fischer shows the maximum and minimum values between which the mean ocean temperature has fluctuated over the past 700,000 years. The results of the reconstruction have just been published in the journal Climate of the Past.

The study’s key findings: Mean ocean temperatures have been very similar over the last seven ice ages, averaging about 3.3 °C colder than the pre-industrial reference period, as already suggested by syntheses of deep water temperatures from marine sediments. However, ocean temperatures in the warm periods 450,000 years ago were much colder and CO2 concentrations were lower than in our present warm period, despite similar solar radiation. The new measurements show that ocean temperature is also shaped by changes in ocean circulation. The so-called global circulation of deep waters has a significant impact on heat storage in the ocean.

“To understand how the climate system’s heat balance is changing,” says Hubertus Fischer, “we have to understand the ocean first and foremost.” For example, 93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere. This means that without the ocean’s heat uptake, the temperature increase measured on land due to human-induced climate change would be significantly greater. However, because the oceans have a huge mass compared to the atmosphere, the temperature changes measured in the ocean today are very small. Measurements on a few ice samples are sufficient

The relevance of data from the ocean for climate research is demonstrated by the international ARGO project, a mobile observation system for the world’s oceans with which for example continuous temperature measurements down to a depth of 2,000 meters have been carried out since 2000. Roughly 4,000 drifting buoys distributed over all oceans are used for this. This makes the approach of Bern’s researchers all the more astonishing in comparison: “We only need a single polar ice sample for our mean ocean temperature measurement,” explains Hubertus Fischer, “of course we are nowhere near the accuracy of ARGO, but conversely we can look far back into the past.” What is being studied is not frozen seawater, but air bubbles trapped in Antarctica’s glacier ice. Specifically: the noble gases argon, krypton, xenon and molecular nitrogen. The majority of these gases are in the atmosphere, just a small fraction is dissolved in the ocean. How well each gas is dissolved in seawater depends on the ocean temperature. Therefore, the changing ratio of these gases in the ice samples can be used to reconstruct past mean ocean temperatures.High-precision gas measurements by Bernese researchers

“The prerequisite for this method are high-precision measurements using a dynamic mass spectrometer,” emphasizes Hubertus Fischer, “which were made possible by the great efforts of several doctoral students and postdocs involved in the publication.” Processing and measurement methods developed in Bern as part of the MATRICs project funded by the European Research Council (ERC) are also crucial. Past ocean temperatures are determined to within 0.4 °C in Bern. This precision makes it possible to trace the climatic ups and downs of the past, since the difference in mean ocean temperature between the ice age and the warm phases over the past 700,000 years was about 3 °C. In addition to the laboratory in Bern, only the Scripps Institute of Oceanography in San Diego, USA, which Bern’s researchers work closely with, has so far carried out such measurements worldwide.

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From EurekAlert!

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Alexy Scherbakoff
April 14, 2021 10:21 pm

What is the connection between gas solubility in seawater and snow on glaciers? I’m not on any medication but I may need to get onto some to understand the logic.

TonyL
Reply to  Alexy Scherbakoff
April 14, 2021 10:53 pm

As the solubility of xenon in seawater increases, for example, we would expect to see a decrease in atmospheric concentration. this decrease would be seen in the atmosphere gasses trapped in the ice cores.

Going further:
Two noble gasses, Argon and Xenon, have different solubilities and those solubilities will have different temperature dependence. Therefor, we expect the Xe/Ar ratio to be temperature dependent. The Xe/Ar ratio will then track ocean temperature.
Two advantages of this method are that a ratio is measured, the absolute concentrations are unimportant which saves you from a difficult absolute calibration problem. The second advantage is that the mass spectrometer can measure ratios to a very high degree of accuracy.

Alexy Scherbakoff
Reply to  TonyL
April 15, 2021 12:39 am

Would that mean that we could take an atmospheric sample now, and ‘discover ‘ what the average ocean temperature is? Without bothering with Argo floats.

The Saint
Reply to  Alexy Scherbakoff
April 19, 2021 6:56 pm

Where are the hockey stick graphs in his analysis?

dk_
April 14, 2021 10:24 pm

“93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.”

Greenhouse gasses store heat underwater. Got it. Great assertion, with no evidence. Ocean temperatures are even harder to measure than atmospheric ones, shortening further the actual record of data for comparison.

Measurements on a few ice samples are sufficient”

Have we figured out exactly how we can precisely measure ocean temperatures from a few polar ice cap samples? What body has calibrated this measurement or validated the procedure? What bearing do sparse data from random floating buoys have on “the pre-industrial reference period.”

philincalifornia
Reply to  dk_
April 14, 2021 11:01 pm

indeed, 93% of nothing = nothing. They can’t even get that math straight.

Reply to  dk_
April 15, 2021 12:04 am

The word “humans” in that statement is not just superfluous, but wrong, even if the 93% number is correct (doubtful).
humans don’t accumulate heat from or due to GHG. Maybe it is language problem for the Swiss researcher.

beng135
Reply to  Joel O’Bryan
April 15, 2021 8:41 am

Perhaps the Swiss researcher’s research is full of holes….

Scarface
Reply to  dk_
April 15, 2021 4:49 am

What he meant to say: models overestimate the presumed effect of human-caused extra CO2 by a factor 93/7.

In related news: citizen scientist discovers that trying to warm the water in his bath tub by heating the air in his bathroom is virtually impossible.

DMacKenzie
Reply to  Scarface
April 15, 2021 6:35 am

CO2 levels in Fig. 9 of the paper are way too close to extinction of plant life on the planet.

Louis Hooffstetter
Reply to  Scarface
April 15, 2021 7:21 am

“citizen scientist discovers that trying to warm the water in his bath tub by heating the air in his bathroom is virtually impossible.”

Ding! – We have a winner!

Dear climate ‘Scientists’: Please explain the physics of how “93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.”?

Mr Julian Forbes-Laird
Reply to  Louis Hooffstetter
April 17, 2021 12:22 am

This would require a violation of the Second Law of Thermodynamics…
“In other news, climastrologists discover that global warming causes emergence of new physics.”

Janice Moore
Reply to  dk_
April 15, 2021 10:20 am

You nailed it, dk. All this is is Trenberth “Where the heck is global warming?”‘s

“missing heat.”

R. B. Hoffmann
Reply to  Janice Moore
April 15, 2021 10:52 am

It’s called “Dark Heat” and very much like Dark Matter. It is there, but cannot yet be seen or measured. All we can do is compare the ratio of gas emitted by one scientist to another and determine a highly accurate measurement.

Janice Moore
Reply to  R. B. Hoffmann
April 15, 2021 1:37 pm

Heh.

Crispin Pemberton-Pigott
Reply to  R. B. Hoffmann
April 21, 2021 12:08 pm

I love the use of the 93/7 split for where “the heat” went. It might be true, but is misdirection. Where is the quantity metric? All we have is a split.

Checking the global temperature in the 1930’s and now, there is not much, in any, to split.

April 14, 2021 10:56 pm

“To understand how the climate system’s heat balance is changing,” says Hubertus Fischer, “we have to understand the ocean first and foremost.” For example, 93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.

More lies and sophistry — 93%? +/- 92.666666%
The basis for the 93% is just fraud by people paid to invent such nonsense. Most CO2 naturally derived. And atmospheric CO2 levels follow temperature changes not lead or cause them.
Hubertus Fischer another fool from the idiot class of paid climate alarmists.

mrsell
Reply to  tom0mason
April 15, 2021 2:34 pm

“we have to understand the ocean first and foremost”

So – we don’t fully understand the oceans. Got it.

Yet, “93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean”.

So which is it? Do we understand the oceans enough to make this factual sounding argument or not?

This is like saying, “I don’t fully understand how an internal combustion engine works but I know that oils containing low zinc concentrations trigger premature pushrod failure”.

Pablo
April 14, 2021 11:20 pm

“..93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean.”

Sunlight warms the surface of the ocean not radiation from the atmosphere.

Overall global ocean temperatures are modified by the temperature of deep ocean waters and this is determined by the source of greatest saline density whether it be polar as it is today or equatorial as in the Cretaceous with its shallow warm low latitude seas and high evaporation.

https://wattsupwiththat.com/2013/10/06/we-must-get-rid-of-the-carboniferous-warm-period/

Editor
Reply to  Pablo
April 15, 2021 2:11 am

Pablo – your “Sunlight warms the surface of the ocean not radiation from the atmosphere.” is spot on. For the benefit of those unfamiliar with the physics : The visible wavelengths of sunlight warm the whole surface layer (the mixed layer). IR from greenhouse gases cannot get past the surface skin, and its energy is mostly lost via evaporation back into the atmosphere and then to space. https://wattsupwiththat.com/2017/02/18/stokes-and-the-somehow-theory-of-ocean-heat/

Louis Hooffstetter
Reply to  Mike Jonas
April 15, 2021 7:27 am

Yes, and to get a feel for just how well sunlight warms the oceans, fill your bathtub with room temperature water, shine a heat lamp on the surface, and measure how long it takes to warm the water 1 degree centigrade.

TonyL
April 14, 2021 11:29 pm

Skip past the 93% comment and the CAGW stuff. That is just dicta needed for research funding these days.

The real value of this is measuring SST across 700,000 years. This will create a record of several full glaciations and several full interglacials.
I checked and found some solubilities in seawater.

Then some solubility ratios between the noble gasses.
This looks to have the potential to be an excellent temperature proxy across a big chunk of this current Ice Age.

Equilibrium-solubility-of-xenon-krypton-and-N-2-in-seawater-of-salinity-35-psu.png
Duker
Reply to  TonyL
April 15, 2021 12:01 am

What’s the scale ? Do they have 700 measurements at every 1000 years. Is this all from Antarctica and what’s the calibration with the surrounding Southern oceans. Seems to be just another reserach project to showcase ‘innovative techniques’ , and that’s the end of it.

TonyL
Reply to  Duker
April 15, 2021 1:30 am

I surfed through the “EurekAlert” and found the link to the actual paper. The whole thing is on-line.
It is quite the read.
Here it is.
https://cp.copernicus.org/articles/17/843/2021/

I just skimmed it. The one thing that really jumps out at you is the dramatic difference between the glacial and the interglacial periods. They have really done a very detailed reconstruction. Lots of measurements, lots of data, lots of error bars.
Also, if you like mass spectrometry and especially Differential MS, the paper is a treat.

beng135
Reply to  TonyL
April 15, 2021 9:09 am

Thanks for that — I couldn’t find anything.

whiten
April 15, 2021 12:35 am

First,
comparing two different datasets, in time resolution
and completely different method, just like that, is kinda of a desperate attempt.

Second,
is completely silly to claim,
afterwards, that radiative
thermal content somehow,
because these dudes say so, it goes almost all of it in the Oceans.

Seems like this particular
dude, and his study, somehow claiming, just like that, from the top of whatever,
that the GCMs, the very climate models, kinda of doing everything wrong basically and specifically.

We really live in amazing times where and when,
anyone using and applying
some novel method of measurement and/or detection, can and owns the full right to lecture the rest, of how everything else
out there works.

Like this lady, which simply
because she owned and could play with a rock cannon in some University basement, could actually tell the world how the Earth the Solar system and the
Universe actually “work”.

Well.

cheers

Joseph Zorzin
Reply to  whiten
April 15, 2021 5:08 am

“comparing two different datasets, in time resolution”
It worked for Mickey Mann.

Robert Heath
April 15, 2021 1:14 am

I think you really do not need to know much science, and certainly not have done many really life experiments, to know this is grasping at straws at best.

Editor
April 15, 2021 1:23 am

I’m having a lot of difficulty believing that this study is robust. I would appreciate comments on the following notes:

What they call “the last seven ice ages” are actually the last seven glacial periods, not that it matters much, but it would be nice to be clear on what they are talking about.

They are using atmospheric gas concentration, not ocean: “What is being studied is not frozen seawater, but air bubbles trapped in Antarctica’s glacier ice.”.

“The majority of these gases are in the atmosphere, just a small fraction is dissolved in the ocean.”. If correct, then the ocean temperature isn’t going to make much difference to their air bubbles. But it would appear to be incorrect anyway:

comment image

“How well each gas is dissolved in seawater depends on the ocean temperature.”. But that’s not what they are measuring.

“Past ocean temperatures are determined to within 0.4 °C”. This seems extraordinarily unlikely, given that they are measuring atmospheric concentration, and (a) “just a small fraction is dissolved in the ocean [?]”, and (b) they appear not to have taken any other possible factors into account (rock weathering, GCRs, meteorites, eg).

“93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.”. Frankly, they have absolutely no way whatsoever of determining this from their ice cores. So what was the point of mentioning it. They say “However, because the oceans have a huge mass compared to the atmosphere, the temperature changes measured in the ocean today are very small. Measurements on a few ice samples are sufficient”. Well, ocean temperature has increased by something like 0.1 deg C over about 60 years. https://wattsupwiththat.com/2020/01/14/the-ocean-warms-by-a-whole-little/ I don’t see how temperatures “determined to within 0.4 °C” can possibly be relevant.

One thing I definitely agree with: “To understand how the climate system’s heat balance is changing, we have to understand the ocean first and foremost.”.

whiten
Reply to  Mike Jonas
April 15, 2021 3:58 am

Yes you are correct about glacial periods.

As far as I can tell,
the “0.4C”, could make some sense, if put like;

“The radiative heat content
of Oceans is equivalent to the Atmospheric radiative thermal content of 0.4C,
in accordance with Atmosphere – Ocean thermodynamic coupling.”

As the “93%” is dubbed as additional heat, it could make some sense if considered as a condition of anomaly, like an error tolerance of the system towards and in regard of
radiative thermal content.

Like,
93% of the amount of the “parasitic”
radiative thermal content,
which remains, despite the
Earth system shedding periodically the main radiative thermal content accumulated,
93% of what does remain,
remains in the Oceans.
Supposedly what remains is approximately 10% of what gets shed.

I agree, that to understand
better the Climate and the
Earth system heat balance,
we have to understand better the oceans and the atmosphere coupling there.

Just sharing a thought
about of how to make some sense if there is any at all there.

cheers

Editor
April 15, 2021 1:36 am

I stopped reading it when I read this nonsense:

“For example, 93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.”

Nicholas McGinley
Reply to  Paul Homewood
April 15, 2021 12:37 pm

Ditto.

RickWill
April 15, 2021 1:58 am

There is a presumption that heat can be stuffed into the oceans from the surface. I question that presumption.

My take is that any increase in deep ocean heat is the result of reduced evaporation. That flattens the ocean thermocline making the oceans less cold. Evaporation drives the meridional overturning current by drawing the cool fresh water from precipitation over the high latitudes toward the equator. The tropical convection pushes water high into the atmosphere. The water vapour level over the southern ocean is 5 to 10mm but reaches 60+ in the tropics so around 50mm gained and lost each circulation of about a month in the South Pacific; almost 2mm/day from tropics to the southern ocean with some ending up on land but still returned to the cycle.

I am yet to confirm an increase in area of the warm pools but net evaporation (evaporation minus precipitation) is negative for the warm pools. For example, the evaporation rate west of South America is much higher than to the East of Australia. So if the warm pools were expanding then the net evaporation would be reducing and the MOC would slow down. The result is that the oceans are measured to be “warmer” but are more accurately termed less cold as the average temperature of all oceans is only a few degrees centigrade. Much colder than the surface.

I doubt that ocean heat content at depth is the result of a warmer surface. It takes hundreds of years for surface temperature effects to be reflected at depth through conductive heat transfer but just decades for reduced rate of evaporation to result in deep ocean heat content to increase.

Last edited 6 months ago by RickWill
Lars P.
April 15, 2021 2:00 am

<i>”For example, 93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere”</i>

I strongly suspect they come to such conclusions due to the fact that 93% of additional heat is missing?

The truth is they do not know what is happening and the models are flawed. The models seem to be based on weather models not including sound heat transfer calculations. Not even the lapse rate is calculated from the models how can they have a proper heat transfer? The CO2 increase does not create additional W/m2 but rather reduces the lengths the radiation of that particular wavelength in the atmosphere (50m to 45m or so). How much heat is transferred with that particular wavelengths? How much is it being changed?

The oceans have a cool skin at the surface – which means the surface is colder then the water a centimeter deeper. There is no way heat is transferred against a heat gradient. “Backradiation” from CO2 cannot go deeper then a couple of microns in the oceans water. Their heat transfer does not work the way they suppose it works.
To make things worse the ARGO data has been adjusted to show warming as the collected data shows a cooling trend.

The water levels in the previous warm period (eemian) about 110 k years ago were 4-5 meters higher then now, so I really doubt the oceans were colder…

Overall these warmist sciences leave a sour taste… Is there any room left for science or have we completely blocked our pathways?

Redge
April 15, 2021 2:11 am

For example, 93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.

So only 7% of the additional heat that humans accumulate by increasing greenhouse gases has caused a 0.5-1℃ of warming.

Crikey!

At this rate when the oceans boil in 10 years time the air temperature will be a gazillion degrees C.

April 15, 2021 2:15 am

Even if you accept all the theory presented, where are the numbers for the actual concentrations of the named gasses in the atmosphere at the time of absorption? Finding, say, 12,35769% nitrogen in your bubble is very clever, but what if that just happened to be the atmospheric content at the time?
Or am I missing something? Like blind faith?

TonyL
Reply to  paranoid goy
April 15, 2021 2:47 am

They are using isotope ratios and atomic ratios. The use of ratios is a standard technique which solves sometimes difficult problems in constructing absolute calibrations.

Reply to  TonyL
April 15, 2021 4:03 am

So I opened your link to the paper. Life’s too short for so many assumptions upon assumptions upon untested theories. At best, this methodology may be compared to carbon dating, riddled with assumptions and localised samples used to ‘calibrate’ for ignored variables. Like solar/ cosmic radiation anomalies.
“To this end, we have to correct the noble gas ratios for gas transport effects in the firn column and gas loss fractionation processes of the samples after ice core retrieval using the full elemental matrix of N2, Ar, Kr, and Xe in the ice and their individual isotopic ratios.”
The Church of the Creationists use similar ‘logic’ to “prove” via isotope ratios in granite, that the earth is just a few thousand years old. Because of them isotopes not having leaked out, see?

Martin
April 15, 2021 2:28 am

I’d love to see their error bars !!

TonyL
Reply to  Martin
April 15, 2021 2:36 am

Here you go.
https://cp.copernicus.org/articles/17/843/2021/

Feast your eyes.

TonyL
Reply to  Martin
April 15, 2021 2:43 am

As a side note, look carefully at the “%” symbol. It is really the double “%%” symbol.
That is the “meg” or millionths symbol. The errors are expressed in meg throughout the paper.
1 meg == 0.0001%, or parts per million.

Martin
Reply to  TonyL
April 15, 2021 3:13 am

Thank you for the link – I read through to the conclusion where a flat rate of uncertainty is stated at plus-or-minus 0.4 degrees Centigrade on temperature a temperature difference of 3.3 degrees over the whole 700Kyr record, or 1.6 degrees for the last 450Kyr

Vuk
April 15, 2021 2:33 am

From number of graphs in the article it is clear that about 8-10 kYrs ago oceans’ temperature was higher than at present. It led to development of ancient civilisations and spread of human races across the globe.
Ergo: warmer oceans are good, and any warming is to be welcome.
On the other hand the same graphs show gradual decline in the oceans’ temperature in the last 8-10 kYrs. This is not such good news, since indicates that the most beneficial part of the interglacial is well behind us. We might have decadal or even centennial ups and downs but we are slowly slip-sliding into another ice age, not very happy scenario for more distant future generations.

R Taylor
April 15, 2021 2:40 am

The work appears to be precise and it confirms what is shown by previous ice-core isotopic analyses of hydrogen and oxygen: Several previous interglacials were warmer than the present one, and the temperature of the present one has trended downwards over the last 8000 years even as atmospheric carbon-dioxide has trended upward.

The authors “refrain from speculating” as to why more recent temperatures are significantly cooler than the “sun revolves around the earth” CO2-temperature-control delusion would require. Unfortunately, the dogma-quotient of their paper suggests that their enlightenment remains unlikely.

Redge
April 15, 2021 5:09 am

Link to Bern University press release

Email from Prof. Fischer:

The 93% of additional heat accumulated in the ocean are not from our own research but from current ocean heat content measurements”

Louis Hooffstetter
Reply to  Redge
April 15, 2021 7:45 am

Two salient points on this:

  1. We only have ~20 years of “current ocean heat content measurements”
  2. The data is in the hands of people who have ‘adjusted’ land temperatures multiple times to fit their agenda.
Nicholas McGinley
Reply to  Louis Hooffstetter
April 15, 2021 12:41 pm

They adjusted the water temperature data too, after the initial findings showed that the ocean was in fact cooling.
Do not believe it?
Here is the guy that did it ‘splainin’ why he had to:

Correcting Ocean Cooling (nasa.gov)

observa
April 15, 2021 5:16 am

Why are they disturbing the penguins and burning fossil fuels with this? Don’t they know the seance is settled?

Steve Z.
April 15, 2021 5:42 am

Geothermal question to anyone…

South Africa has several mines that are around 10,000 feet deep. The temperature of the mine walls at that depth is around 150 degrees F.

The average depth of Earth’s oceans is around 10,000 feet.

If all the water in the oceans evaporated, would the average temperature of the now completely dry sea floor also be around 150 degrees F?

If not, why not?

Thank you very much for explaining this!

Pablo
Reply to  Steve Z.
April 15, 2021 6:02 am

Not sure about that, but Earth without a sun would have a temperature of 33ºK. The exact difference between todays average surface temperature and its theoretical black body temperature.

https://www.businessinsider.com/how-long-life-could-survive-if-the-sun-went-out-2013-7?r=US&IR=T

Steve Z.
Reply to  Pablo
April 15, 2021 6:30 am

Re: 33 K

Yes, because the Earth’s current land surface is at sea level or higher, and its temperature is usually very close to the ambient air temperature.

What happens when you strip away 10,000 feet of insulation?

Is the temperature of dry exposed land 10,000 feet below sea level 150 degrees F, like the mines in South Africa?

If not, why not?

Pablo
Reply to  Steve Z.
April 15, 2021 7:13 am

33K is minus 240ºC

Nicholas McGinley
Reply to  Pablo
April 15, 2021 12:44 pm

Yes, even Pluto has a Sun.
Earth without a Sun was not the question, was it?

Pablo
Reply to  Nicholas McGinley
April 15, 2021 1:56 pm

The average temperature of the surface is the same as the average air temperature after input into the system from the sun…. the limit of cooling. The geothermal heat from the interior alone would seem to result in a surface temperature of 33ºK so there is a head start of 33ºK (equivalent to 33ºC at the same scale) to any warming that the sun can provide.

See TonyL below for the direct answer.

TonyL
Reply to  Steve Z.
April 15, 2021 8:18 am

No.
Consider a thick layer of insulation with a heat source below and some ambient temperature above, a heat sink. After we get to equilibrium, there will be a high temperature a the bottom equal to the heat source temperature. At the top, the temperature will be the same as the heat sink. Across the insulation layer, there is an even temperature gradient with the temperature decreasing in a linear fashion from bottom to top. The temperature change is directly proportional to the depth into the insulation one measures.

Now consider the Earth. The upper mantle is the heat source. The Earth’s crust is the insulating layer. Lets make up a number, say 50,000 feet thick. Now the bottom of the mine is 20% of the way through the insulation layer. 80% below you and 20% above. You see a delta T of 150 degrees. We can now infer that the upper mantle below your mine has a temperature of 750 degrees.

If you strip off 10,000 feet of crust, *after equilibrium* the surface will still be at the heat sink ambient, but you will have increased the heat flow by 20% just because the insulation is thinner.

gbaikie
Reply to  Steve Z.
April 15, 2021 9:44 am

–If all the water in the oceans evaporated, would the average temperature of the now completely dry sea floor also be around 150 degrees F?
If not, why not?–
150 F {65 C}.
When the Mediterranean sea dried up, it’s thought the dried basin floor was as high as 80 C:
https://en.wikipedia.org/wiki/Messinian_salinity_crisis
So, it might reasonable to assume this, but what is a certainty is dry ocean floor would have warmest air on Earth.
But that is like saying that currently sea level is the warmest air {as compared 1000 meter or higher}- it’s certainly true.
I would say if removed the ocean, Earth would absorb less sunlight. But the more air masses above ocean basin it would retain more heat. And of course where we living on land continents
would have less atmosphere above them and be radiating more energy directly to space and they would be much colder than they are currently, and question is how cold?
If really cold, they going radiate less energy directly into space.
To make simple, dry ocean basin might be 80 K warmer than Los Angles, but LA might have average temperature of -40 C. And that increase Earth global average surface temperature though LA could be colder than -50 C.

gbaikie
Reply to  gbaikie
April 15, 2021 10:29 am

Let’s say add atmosphere to replace the removed ocean.
Or land has the same amount atmosphere above.
Land average temperature is currently about 10 C.
I believe land is 10 C due to warmer ocean surface and also when considering
the tropical ocean being the “heat engine of the world”.
But suppose this is false, let’s say average land temperature remains at 10 C- and
the air filled ocean basin is much warmer.
Well I think water vapor has warming effect, and our land would very dry- Mars dry.
So if leave some water in basin, it could have water vapor. But even left ocean of 100 meter depth in the ocean, it’s not going to make our current land, wet. It’s as dry or drier than Mars. Or Mars has 210 ppm of water vapor in it’s atmosphere. And as guess we currently have about 4000 ppm of water vapor over land:
4000, 2000, 1000, 500. Or from 500, it’s doubling at least 3 times. And water vapor is stronger greenhouse gas than CO2. So from this effect it can lower the land average of 10 C. Some might say by 10 C or more. I will say by 5 C.
Say a 5 C average land of our current continental land. I will leave it at that.

Nicholas McGinley
Reply to  Steve Z.
April 15, 2021 1:08 pm

If one could built a glass tube that reached all the way from the ocean bottom to the surface, and was a mile wide say, what would be the temp at the surface of the ocean floor?
Under that condition, we could use the lapse rate to get a number.
If the ocean floor at that location was 10,000 feet below the surface, that would be 10 times the environmental lapse rate per 1000 feet. Which of course varies considerably with the weather.
But using the average fair weather ELR (lapse rate) of 3.56°F/1000′, the number would be 35.6° F higher than the surface. Simply from atmospheric pressure alone.
If we use the dry adiabatic rate of 5.38°F/1000′, the surface at that depth would be 53.8° F higher than the surface.
So if it was 97°F at the top of that tube, it would be something like 150° at the bottom.
If we ignore than the glass walls are close to 32° F and would be cooling the air inside of there.
The opposite happens in a deep mine in South Africa. There, the rock is hot and warms the air even more than the difference in atmospheric pressure alone does. In fact I think the air (and mine walls) is that hot because the rock is that hot.
Rock is basically incompressible, and so lapse rates have nothing to do with the temp there.
So what does matter?
The geology of the rock has a large effect, and it varies from place to place, of course.
The Temperature Of The Earth As Shown By Deep Mines (chestofbooks.com)

In general though, the geothermal gradient cause by heat flowing from the mantle through the crust is given as between 72 and 87° F/mile of depth, near the surface.
A mile is 5,280 feet.
So two miles down, on average, we should expect it to be well over 150°F hotter just from the geothermal gradient.
Closer to the surface, say around water table depth, the average annual mean temp of the air gives a very close approximation for the temperature of the ground.
IOW…in most places, away from geothermal features, the water drawn from a well is the same as the average annual air temp.
Here in Florida, that varies from north to south.
It is around 72°F near Tampa, and a few degrees warmer near Fort Myers.

Geothermal gradient – Wikipedia

Last edited 6 months ago by Nicholas McGinley
Nicholas McGinley
Reply to  Nicholas McGinley
April 15, 2021 1:12 pm

comment image

Tom in Florida
April 15, 2021 5:54 am

“A dynamic mass spectrometer”
I wonder if that thing is turbocharged?
(Probably only on the floor models)

Clyde Spencer
April 15, 2021 8:28 am

This means that without the ocean’s heat uptake, the temperature increase measured on land due to human-induced climate change would be significantly greater.

The above statement is really a non sequitur because we do have an ocean and the specific heat of water is a universal constant. Thus, things are as they are because they couldn’t be any different! If the oceans were to evaporate, we wouldn’t survive the event!

A bigger concern for the alarmists is why there should be fear about the heat accumulating in the ocean when heat moves by conduction from warm bodies to cool bodies. That heat isn’t really going to go anywhere! What happens in the ocean stays in the ocean!

Last edited 6 months ago by Clyde Spencer
ATheoK
April 15, 2021 9:36 am

When the lead author uses bovine excrement confirmation bias assumptions, e.g.;

“For example, 93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.”

How could any rational person accept any of this research’s other claims?

Bro. Steve
April 15, 2021 11:03 am

No mention of changes in atmospheric pressure over time?

https://en.wikipedia.org/wiki/Henry's_law

Greg
April 15, 2021 11:38 am

However, ocean temperatures in the warm periods 450,000 years ago were much colder and CO2 concentrations were lower than in our present warm period, despite similar solar radiation.

Of course. Henry’s law on solubility of gases.

How well each gas is dissolved in seawater depends on the ocean temperature.

And the same goes to CO2. It is NOT CO2 which is driving temperature.

Smart Rock
April 15, 2021 11:41 am

We only need a single polar ice sample for our mean ocean temperature measurement

I wonder. Specifically, I wonder how much of the ocean they are estimating the mean temperature of. Obviously, that which is in equilibrium with the atmosphere, and how much is that? Does anyone really know?

I went looking for the original because the news release writer got it wrong again: “ocean temperatures in the warm periods 450,000 years ago were much colder“. It turns out that they should have said “ocean temperatures in the warm periods BEFORE 450,000 years ago were much colder

Their figure 6 is informative. I screencapped it to show the captions:

What is notable (assuming their numbers are reliable) is that the last interglacial (the Eemian) comes in with a δT of about +1°C. The previous three interglacials also showed positive deviations relative to the Holocene.

Look at the numbers for the 320,000 kA point; they vary from -1° to +7°. Big spread! Give them credit for including such dubious numbers and not cherry picking as some climatists (who shall remain nameless) would do.

If I was writing the headline for this article, it would have read:

“EEMIAN OCEANS WERE 1°C WARMER THAN IN THE HOLOCENE. DON’T PANIC!”

Figure 6.jpg
Bruce Cobb
April 15, 2021 11:42 am

Too bad they didn’t name the journal: “Climate: Changing the Past for a Better Future”.

Gordon A. Dressler
April 15, 2021 11:46 am

From the above article’s last paragraph:
“Past ocean temperatures are determined to within 0.4 °C in Bern. This precision makes it possible . . . “

Actually, the claimed precision is obviously not based on any direct measurement of “past ocean temperatures”, but instead is based on inferring temperature from asserted-to-be “precise” measurements of one or more ocean temperature PROXIES. Now what could go wrong with that? . . . thinking about tree rings as a proxy? . . .

Also this from the second-to-last paragraph of the above article:
“How well each gas is dissolved in seawater depends on the ocean temperature.”
But gas solubility in seawater also depends on other significant variables, such as salinity, gas partial pressure above the water surface, diffusion through floating surface ice if present, diffusion/convection through subsurface concentration gradients which in turn are affected by ocean currents or lack thereof, etc.

Combine these issues the Bern researchers’ claim they can derive global mean ocean temperatures just using a few ice cores from Antarctica, when in fact nobody can accurately state how global ocean circulation patterns have varied over the last 700,000 years. Really?

Sorry, but the above article is just not scientifically credible.

Last edited 6 months ago by Gordon A. Dressler
Nicholas McGinley
April 15, 2021 12:30 pm

“For example, 93 percent of the additional heat that humans accumulate by increasing greenhouse gases is currently stored in the ocean rather than in the atmosphere.”

93% of nothing is nothing, so this is not even wrong.

Last edited 6 months ago by Nicholas McGinley
David Solan
April 15, 2021 4:19 pm

 I believe using ratios of noble gases and molecular nitrogen trapped in ice cores
is a valid scientific method to determine long-term, historic oceanic temperatures.
So, in criticizing the recent remarks of the researcher from the University of Bern
with regards to “carbon dioxide/methane greenhouse warming” in the atmosphere
magically relating to those ratios of molecules/isotopes trapped in ice cores — and
to the oceanic temperatures they indicate (assertions studiously emphasized in the
original research paper) — we must not throw out the baby with the bathwater.

  I believe in the conclusion of those researchers that a very large fraction of any
excess heat that might have entered the Earth (of course, from the Sun) in the past,
raising its overall temperature, has been sequestered in the oceans and only a very
small amount has manifested itself in the atmosphere and on the land surface of the
Earth. After all, about 70% of all sunlight falls on water in the first place when it
reaches Earth’s surface. And water has a thermal capacity of about 700 times air. And if the heat absorption mechanism operating here involves mainly the oceans and NOT the atmosphere, that would clinch the conclusion. Notice that this conclusion is entirely separate from the glib remarks of one of those Bern researchers that this extra thermal energy is coming from “increasing greenhouse gases”, which, to put it mildly, is mind-blowing, junk science (though it will earn him Liberaloid brownie points). How can a hot atmosphere efficiently conduct its heat, through infrared radiation, over a matter of a few hundred years, downwards into the oceans so that they eventually retain 93% of that heat?

  This overriding sequestration of thermal energy in the oceans is what can cause,
over time, vast amounts of floating ice (shelves or otherwise) in the vicinity of the
poles to melt, sometimes endangering the sheet ice they were protecting from meeting the same fate. And this is what can cause, over time, ocean levels to rise (through thermal expansion or net sheet ice melting overcoming snow accumulation). And it can add a lot of noise to average global (surface) temperature graphs plotted against time, as vertical ocean currents can bring up or take down vast amounts of heat from and into the depths of the ocean over 10-year time frames. In other words, global climate researchers should be thinking a lot more about the oceans than the atmosphere.

  Those Bern researchers are also maintaining that in the present interglacial the
oceans are anomalously warmer than in the past 6 ones, which is a very intriguing
insight (which I also believe is true, though controversial).

  Thus, this is very important research, unfortunately, marred by numerous,
gratuitous, politicized remarks thrown in by the research leader as an afterthought.

Brooks H Hurd
April 16, 2021 7:22 am

I would really like to see the error analysis for this project. The quantity of assumptions which are required to assume that their precise measurements of ice core gas bubbles accurately represents the concentration of gases in the air from 700 centuries before the present is truly mind numbing.

Last edited 6 months ago by Brooks H Hurd
paul courtney
April 16, 2021 12:19 pm

Looking at the ice core laid horizontally, it could be a 700,000-year handle- using a “nature-trick,” we could graft modern temp records onto it, as a blade (going up, very scary), and we’d have evidence of AGW. Simples.

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