#AGU16 Earth’s Magnetic Fields Could Track Ocean Heat, NASA Study Proposes

From the “Thermometers? We don’t need no steenkin thermometers!” department and NASA comes this interesting story. Video follows.

As Earth warms, much of the extra heat is stored in the planet’s ocean – but monitoring the magnitude of that heat content is a difficult task. A surprising feature of the tides could help, however. Scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean.

As Earth warms, much of the extra heat is stored in the planet’s ocean – but monitoring the magnitude of that heat content is a difficult task.

A surprising feature of the tides could help, however. Scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean.

The method depends on several geophysical features of the ocean. Seawater is a good electrical conductor, so as the saltwater sloshes around the ocean basins it causes slight fluctuations in Earth’s magnetic field lines. The ocean flow attempts to drag the field lines along. The resulting magnetic fluctuations are relatively small, but have been detected from an increasing number of events including swell, eddies, tsunamis, and tides.

The magnetic fluctuations of the tides depend on the electrical conductivity of the water – and the electrical conductivity of the water depends on its temperature. This new method could be the first to provide global ocean heat measurements, integrated over all depths, using satellite observations.

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oeman50
December 13, 2016 9:31 am

The electrical conductivity also depends on the salinity and total dissolved solids (TDS) which can vary.

TA
Reply to  oeman50
December 13, 2016 10:01 am

There you go, complicating things.

george e. smith
Reply to  TA
December 13, 2016 11:02 am

Do you have a spare bridge or two lying around you would like to sell me ??
I have this fetish for new gimmics.
G

Aphan
Reply to  TA
December 16, 2016 8:47 am

I know right? Why don’t they just ask Trenberth? He knows exactly how much the ocean has warmed, at every depth, along with how much missing energy to add in, so surely he can easily do the math and come up with the average global temperature of the ocean. It’s all KNOWN right? 🙂

MarkW
Reply to  oeman50
December 13, 2016 10:17 am

Not just vary, but vary a lot.

stevekeohane
Reply to  oeman50
December 13, 2016 10:39 am
Christopher Paino
Reply to  oeman50
December 13, 2016 11:10 am

I am as layman as they come, and that was my very first thought.

aaron
Reply to  oeman50
December 13, 2016 1:58 pm

Do cosmic rays affect ionization and conductivity?

TonyL
December 13, 2016 9:41 am

This could be a most interesting approach. Complex, difficult, but apparently achievable. Seems like such a method would lend itself well to producing a global integrated average. That in itself would sidestep issues caused by gridding discreet data points like interpolation infilling, extrapolation, and homogenization.

MarkW
Reply to  TonyL
December 13, 2016 10:19 am

It’s only useful if you assume that the only thing changing is the temperature of the water.

TonyL
Reply to  MarkW
December 13, 2016 11:19 am

Turn the situation over. Assume constant temperature, now you are measuring ocean currents. With all the minor variations going on all the time, I would bet that an El Nino event would stick out like a beacon in the night. Year on year, constant temp is probably a safer bet anyway, but not what they want.
So how to calibrate?
Remember, you are not working in a vacuum, things like ARGO and TAO will be useful. ARGO measures current drift as well as temp. Signal events like an El Nino might prove useful as an internal reference.
Like I said, “Complex, difficult”, the easy stuff has already been done. What is left is going to be hard.
As the wise man said; If you find “hard” to be too daunting, maybe you are in the wrong line of work.”

Greg
Reply to  MarkW
December 13, 2016 1:23 pm

“Turn the situation over. Assume constant temperature, now you are measuring ocean currents. ”
No, turn the siltation over and think of ALL the other things that could affect the geomagnetic field. Lets start with what causes the geomagnetic field and it is not the ocean currents. We are usually told it is currents of molten nickel and iron in the earth’s molten core that no one has ever observed. We could also ask about movement in the ionosphere causing massive currents and hence magnetic fields.
Then of course there is interactions with solar magnetic field and the solar wind of charged particles.
In short this is slightly less credible as temperature proxy than pretending that the only thing which affects the thickness of tree rings in temperature.
Tracking is one of those ‘please talk down to me ‘ unscientific terms, like “lock-step” which gets my BS detector flashing like a beacon. Usually an alert for a spurious claim.

Reply to  Greg
December 13, 2016 1:35 pm

No, turn the siltation over and think of ALL the other things that could affect the geomagnetic field.
None of these are relevant as the signal is very sharply timed by the Moon.

Hivemind
Reply to  TonyL
December 13, 2016 1:40 pm

I think it’s too open to manipulation to achieve the narrative you want. Want to remove the Medieval Warm Period? Assume new values for the total dissolved solids in that time window & there you have it. No more MWP.

Harry S
December 13, 2016 9:42 am

Let me guess the data processing and conclusion: based on the magnetic field and adjusted data modeling of recorded ocean temperature to bring temperature readings onto one consistent datum, ocean heat has been showing a steady rise for 150 years and it’s now worse than we thought requiring immediate action.

Paul
Reply to  Harry S
December 13, 2016 9:54 am

“it’s now worse than we thought requiring immediate action.”
Nope, it’s already too late. Send money anyway.
“…and the electrical conductivity of the water depends on its temperature”
Seems the changes they’re looking at would be quite small. wiki says:
“…assuming a linear increase of conductivity versus temperature of typically 2% per degree Celsius”
And IF they are equating sea water to an electrical conductor in a magnetic field, doesn’t that mean the tides are producing energy?

Michael
Reply to  Paul
December 13, 2016 10:34 am

And solar flaring?

Aphan
Reply to  Harry S
December 13, 2016 9:57 am

No study even needed Harry! You just saved the American people billions of dollars!!! *grin*

TW
Reply to  Harry S
December 13, 2016 10:08 am

Yes, if the satellite data gives the desired result. But no, if these satellites are like the microwave sensors and give the wrong result, then the story will be, “we just need to go back to thermometers.” By the way, didn’t we just spend, how much?, setting up the ARGO system?

george e. smith
Reply to  Harry S
December 13, 2016 11:03 am

And you hold your licked finger up to see which way the wind is blowing.
g

Pop Piasa
Reply to  george e. smith
December 13, 2016 9:46 pm

Gene Simmons just uses his tongue.

rocketscientist
December 13, 2016 9:47 am

Too many other uncontrolled variables to be able to determine that temperature is the reason for any magnetic changes. Just another red herring from which to claim numerous unsubstantiated conclusions. This is merely another method of very precisely measuring marginally useful data.

Reply to  rocketscientist
December 13, 2016 9:57 am

Indeed. In order to extract temperatures to the now customary tenths of a °C you would need to be able to specify the precise speed and direction of current flow at all depths and the corresponding salinity values. You might make some estimate of those parameters but your temperature estimate could could be no better than those estimates and the error bars would almost certainly be greater than the ΔT you are claiming to measure.
It does give huge scope for post hoc *adjustments* though which will be viewed as a marvelous thing in some quarters.

george e. smith
Reply to  cephus0
December 13, 2016 11:05 am

Well one good thing: because the earth does not rotate in NASA’s global models, you don’t have to worry about tidal flows. The sea height is what it is; always.
g

Bryan A
December 13, 2016 9:52 am

I wonder if this could ba a NASA rush to publish in a vain attempt to prove their worth prior to the beginning of the Trump Administration? If it is, there would surely be additional publications of more works of faction. Unfortunately however, rushing to publish is what leads to errors that provide for future untrustworthiness of their work.

Oldseadog
December 13, 2016 9:53 am

I would hope that, at first anyway, any measurements of temperature taken this way are backed up by actual measurements taken by thermometers to calibrate the system.
Naive? Cynical? Me?

Steve Fraser
Reply to  Oldseadog
December 13, 2016 10:39 am

The new system would need calibration, and a certification test. I propose a research area of the entire North Atlantic, with in-situ, realtime measurements of the entire area on a 10 km grid by ships, placed buoys and the satelite((s), to a depth of 1000 meters or the sea floor, whichever is deeper, in 100-foot depth increments, and with coincident, corresponding measurements and analysis by TSS and Dr. Spencer’s group of,their own systems.

G. Karst
December 13, 2016 9:56 am

Just off-hand – sounds as bad as tree rings – too many critical parameters to adjust. GK

Aphan
Reply to  G. Karst
December 13, 2016 10:01 am

But the more critical parameters there are to adjust, the easier it is to get the data to say what you want it to.

Berényi Péter
December 13, 2016 10:01 am

I am sure there are lots of open parameters. And it takes time to tweak each one to show a steady rise in ocean heat content. Therefore it is imperative to have as many backups of published data as possible, because it will keep changing retrospectively without notice. A proper revision control system would, of course, solve the problem once and for all, this is why it will never be implemented.

December 13, 2016 10:01 am

The missing heat is in the oceans – was this excuse no. 70?
These and many other studies of variables are nothing but Distractions to keep the skeptic scientists busy with minutiae. It is like the shell game – where is the pea?
Just like politics – and it works.

Hivemind
Reply to  kokoda
December 13, 2016 1:43 pm

More like a game of whack-a-mole.

December 13, 2016 10:12 am

Color me very skeptical for several reasons. Seawater conductivity depends on salinity more than temp. For the bulk of the ocean below the thermocline Argo shows average temp at 2000 meters (average ocean depth is 3700, this is halfish depth) is ~2.5C, and the global variation is ~+/- 0.5C. Very little temperature signal to play with. OTH, significant salinity differences both with depth and by location given the thermohaline circulation.
Oceans slosh during a tunami, but not normally. I just checked and there is no sloshing on the Fort Lauderdale beech today.

Stephen Greene
December 13, 2016 10:18 am

Without constant sampling of the water it would be impossible to obtain worthwhile signal to noise ratio’s and significant enough temp resolution. And even then huge error bars if this is indeed possible. Which I think they better keep them this time. MY OPINION
More grant money anyone?

Irrational D
December 13, 2016 10:18 am

Oh great, another complex proxy measurement inserted into another climate model. I am confident that will work out well. (sarcasm intended) Can not wait for the articles on how the number of active electric eels (Electrophorus electricus) is interfering with the calculation of ocean temp derived from satellite measurements of magnetic field strength.

MarkW
December 13, 2016 10:18 am

Would increasing carbonic acid influence the conductivity of sea water?

December 13, 2016 10:40 am

The variation of the geomagnetic field of electric currents induced in sea water has been known and measured for more than a century [the “ocean effect”] and was even predicted by Faraday back in 1832. The conductivity depends on salinity [that does not vary globally] and temperature [that may, over time] so it might well be possible to back out the temperature influence.

commieBob
Reply to  lsvalgaard
December 13, 2016 10:59 am

… salinity [that does not vary globally] …

This map shows it varying between 30 and 40 grams per kg. It can be a lot less in estuaries.

Reply to  commieBob
December 13, 2016 11:02 am

I said ‘globally’. Averaged over the oceans the number of ions does not vary on time scales of interest.

commieBob
Reply to  commieBob
December 13, 2016 11:24 am

lsvalgaard December 13, 2016 at 11:02 am
I said ‘globally’. Averaged over the oceans the number of ions does not vary on time scales of interest.

They are trying to measure the temperature based on the flow of sea water disrupting the magnetic field. Salinity is really important as a determinant of the water’s conductivity. Here’s a link to a nice video showing salinity variation in the planet’s oceans.

Reply to  commieBob
December 13, 2016 11:35 am

Globally the salinity depends on the total number of Sodium and Chlorine ions in the entire ocean which only changes on geological time scales.

MarkW
Reply to  commieBob
December 13, 2016 12:08 pm

Nobody cares what the global number is. They are measuring changes point by point, which means they need to know what the salinity is for the point that they are measuring at the time they are measuring it.

Reply to  MarkW
December 13, 2016 12:18 pm

The measure the global temperature you will care about the global numbers.

rocketscientist
Reply to  commieBob
December 13, 2016 1:01 pm

The salinity of the Mediterranean Sea varies from one end to the other due to evaporation alone. The convective currents caused by this density differential were exploited by submarines traversing the straights of Gibraltar.

Reply to  rocketscientist
December 13, 2016 1:31 pm

Completely irrelevant for the GLOBAL solution.

Peter Morris
Reply to  lsvalgaard
December 13, 2016 11:24 am

But how do you isolate the other effects on the magnetic field to subtract them out? It varies naturally, but how do we know what’s the ocean signal versus the noise from the theorized molten dynamo?
I’m assuming we can subtract out the sun’s influence on it by using data from the solar monitoring satellites. There may be other variables as well.

Reply to  Peter Morris
December 13, 2016 11:29 am

This problem was solved a century ago. The trick is to realize that the tidal effects are short-lived [hours] and their timing is extremely well-known and predictable [the Moon’s orbit].

Reply to  lsvalgaard
December 13, 2016 12:01 pm

Thanks for your insights, Leif. While the salinity doesn’t vary globally, it does definitely vary over the globe as well as vertically in the ocean. From above:

Note that this is a long-term average, but in actuality the salinity is constantly changing at every point. This means that conductivity varies over the globe based not on temperature alone but including the salinity variation (and a small variation based on pressure). Here’s a profile of the vertical variations:

Conductivity vs pressure is at the upper right. You can see the pressure effect at depth, where temperature and salinity are unchanging but conductivity rises. Given this huge vertical variation in conductivity, and given this vertical variation will be different in every part of the ocean, and given that it will also be different during different seasons … just how large can we expect the uncertainty be on any such proxy measurement of temperature?
Next, in order to calibrate a proxy such as satellite measured magnetic fields to use it to calculate ocean temperature, you typically have to adjust various tunable parameters in your equation to match reality … but unfortunately, we don’t know the temperature of the ocean, particularly the ~ half of the ocean that is below 2 km depth. Makes tuning hard, increases the uncertainty …
Finally, it seems to me that what they are doing is akin to a CAT scan. They have measurements of disturbances in the force, to coin a phrase. They need to work backwards from that. First they need to figure the variations in magnetism at satellite height. Then for each spot in space they need to remove all of the variations that are not related to the ocean—inherent variations in the geomagnetic field, changes in heliomagnetism, and changes in the solar wind are the first that come to mind, but there are likely others.
Then they need to remove the variations caused by changes over time in salinity, not just at the surface, but all of the way from the surface to the bottom.
Then there’s the elephant in the room, something that they haven’t even begun to discuss—variations in conductivity due to LIFE. I’ve never seen numbers on that, but I would bet good money that the conductivity of the green water along the coast near my house here in California, water bursting with verdant life, is very different from the conductivity of the crystal-clear blue water just sixty miles (100 km) offshore. Variations in both the amount and type of life in the water will make corresponding variations in conductivity.
Then there is the whole question of “suspended solids”. These can also change the conductivity of seawater, at times greatly, and in unforeseen ways. For example, huge amounts of mineral dust from the Sahara are periodically deposited across a huge area of the Atlantic … how does this change the magnetism out in space?
So then, at the end, they end up with what they THINK is the magnetic variation in every spot in space due solely to the ocean … but that still isn’t the temperature. They then need to use a 3-D CAT-scan-like model of how the magnetic field surrounding the earth relates to the actual variations in conductivity in the ocean.
And at the end, once they have created a 3-D model of oceanic conductivity, they then need to tune the model parameters to match what little we know of oceanic temperatures …
Steve McIntyre has spoken before of an uncertainty that goes “from floor to ceiling”, and the results of this long and torturous voyage from satellite-measured magnetism to ocean temperature certainly fit that picture. I can’t imagine this being anything near useful in the real world.
As always, Leif, my best regards,
w.

Reply to  Willis Eschenbach
December 13, 2016 12:07 pm

Well, globally over the world ocean the total number of Sodium and Chlorine ions does not vary on time scales we are interested in. So the globally averaged conductivity should be pretty constant if it were not for variations of global temperature. All this was understood a century ago.

commieBob
Reply to  Willis Eschenbach
December 13, 2016 2:01 pm

lsvalgaard December 13, 2016 at 12:07 pm
… the globally averaged conductivity should be pretty constant if it were not for variations of global temperature.

The problem is that the satellites are not measuring one global value for magnetic field. They are measuring the field as they orbit the planet. It’s a fairly localized measurement. In that regard, the conductivity of the water matters on a fairly local scale.
The video doesn’t have a lot of words but the images clearly indicate that the changes they are looking at are regional.
I agree with numerous other posters who have pointed out that the number of confounding variables seems to make the temperature measurement project very dodgy.

Reply to  commieBob
December 13, 2016 2:11 pm

The problem is that the satellites are not measuring one global value for magnetic field.
They are measuring millions of values covering the globe in space and in time. From that, global quantities can be determined, e.g. the Magnetic Moment of the Earth and the global ocean effect.

commieBob
Reply to  Willis Eschenbach
December 13, 2016 4:23 pm

lsvalgaard December 13, 2016 at 2:11 pm
… From that, global quantities can be determined,

Consider this problem. The polarity of the magnetic field generated by the tide depends on the direction the tide is flowing. An incoming tide might boost the Earth’s magnetic field. An outgoing tide would buck it. Over the surface of the globe, the incoming tides will approximately equal the outgoing tides. The result is that their magnetic fields will cancel if you’re trying to integrate to get a global value for the planet’s magnetic field.
The use of electromagnetic principles for oceanographic studies is not new. Here’s an interesting paper from the 1980s.

Reply to  commieBob
December 13, 2016 8:42 pm

We are not trying to measure the Earth’s ‘magnetic field’, but rather the small perturbation [like one in 10,000] caused by the tides. This has been done successfully for more than a hundred years [was actually first done by Kreil in the 1840s].

commieBob
Reply to  Willis Eschenbach
December 14, 2016 4:06 am

lsvalgaard December 13, 2016 at 8:42 pm
We are not trying to measure the Earth’s ‘magnetic field’, but rather the small perturbation [like one in 10,000] caused by the tides.

Right.
The reason to use a satellite is that variations in magnetic field are quite local, otherwise we could just have a stationary instrument couldn’t we. The variation you measure will be the variation caused by the nearest tide.

Tidal currents are periodic with a net velocity of zero over the particular tidal cycle. link

That means the magnetism induced by the tidal electric current will cancel out. That means we have to calculate our temperatures locally. That, in turn, means we have to take salinity variations into account. We won’t get valid results by assuming that the errors will just average out.

Reply to  commieBob
December 15, 2016 12:26 pm

The reason to use a satellite is that variations in magnetic field are quite local
No, the lunar effect due to the conducting oceans are quite global [the oceans are large]. The locally varying perturbations on the global average are not important on the scale of oceans. All this is well-known [and has been for more than a century].
That means the magnetism induced by the tidal electric current will cancel out
Not at all. The magnetic effects are cumulative and have been measured for a long time. What will cancel out are the variations in salinity, as those do not vary time-locked to the lunar phase.
I don’t know what your problem is. The proposed technique has great promise and is eminently possible, based on well-understood physics.

commieBob
Reply to  Willis Eschenbach
December 15, 2016 2:50 pm

lsvalgaard December 15, 2016 at 12:26 pm
… I don’t know what your problem is. …

You really have to explain why the magnetic fields caused by the electric current due to the east flowing (tidal water) current do not cancel with those due to the west flowing current. The direction of the electric current in a conductor moving through a magnetic field depends on the direction of motion; ditto for the resulting magnetic field caused by the current flowing through the conductor. This is always taught in the first or second physics course. I agree, the physics is well understood.

Reply to  commieBob
December 15, 2016 2:54 pm

The induced current is basically due to the magnetic Earth rotating inside the conductive sea water bulge raised by the Moon, and the Earth rotates only one way.

commieBob
Reply to  Willis Eschenbach
December 15, 2016 7:08 pm

lsvalgaard December 15, 2016 at 2:54 pm
The induced current is basically due to the magnetic Earth rotating inside the conductive sea water bulge raised by the Moon, and the Earth rotates only one way.

It is tempting to view the bulge as a conductor rotating within the planet’s magnetic field. I see that. From that standpoint it looks like a conductor moving at around 1000 mph through the Earth’s magnetic field.
The first thing we should get out of the way is the size of the bulge. In mid-ocean it’s mostly less than a foot. link.
As this link makes clear, the thing that is responsible for the electric current is the actual velocity of the water. We can ignore the vertical velocity because, in mid-ocean, it’s less than two feet per six hours (approx.). We then have the flow toward the bulge from each side which, in mid-ocean, isn’t much.
Things get more interesting on the continental shelves and near the shore. The horizontal velocities become significant but they cancel over the tidal cycle. In any event, I can think of no point, except a waterfall, where the water velocity is within an order of magnitude of 1000 mph. 🙂
The bottom line is that the counter magnetic field generated by the tides is local. Over time and space it cancels.
Getting back to where we started, the local salinity has much more effect on electrical conductivity than the local temperature.
If you can find some references that contradict what I’ve said, I will gladly eat crow. It tastes like chicken.

Reply to  commieBob
December 15, 2016 9:05 pm

I don’t need to correct you. You need to consider that my explanation was crude and a vast oversimplification. The salient point had to do with the issue of direction. I hope you got that to your satisfaction. The issues about salinity and local topology are that they do not vary on the time scale of the tides or even decades or centuries, so fall out of the equation. The temperature may vary on those time scales and that variation may leave a signature in the magnetic field variation.

commieBob
Reply to  Willis Eschenbach
December 16, 2016 4:18 am

The issues about salinity and local topology are that they do not vary on the time scale of the tides or even decades or centuries, so fall out of the equation.

Salinity does vary and therefore does not fall out of the equation.
Here’s a link to a video that shows salinity variation.
Here’s a link to a relevant paper. It describes: “Large halocline variations in the Northern Baltic Proper and associated meso- and basin-scale processes”.

Reply to  commieBob
December 16, 2016 7:49 am

The salinity averaged over the world ocean [i.e. the total number of sodium and chlorine ions] does not vary on the time scale of the tides [12 hours] and that is the important point for using the world-wide satellite data to measure the global sea temperature.

commieBob
Reply to  Willis Eschenbach
December 16, 2016 9:46 am

lsvalgaard December 16, 2016 at 7:49 am
The salinity averaged over the world ocean [i.e. the total number of sodium and chlorine ions] does not vary …

You keep asserting that. I keep explaining why it doesn’t matter. You don’t explain why my facts or logic are wrong, you just keep repeating your mantra.

Reply to  commieBob
December 16, 2016 9:52 am

I keep telling you why your view doesn’t matter. In my considered opinion the proposed method will work and has promise. You don’t think so, and so will miss out. It is, of course, your prerogative to close your eyes to progress. Many people do, so you are in good [bad?] company.

commieBob
Reply to  Willis Eschenbach
December 17, 2016 5:49 pm

lsvalgaard December 16, 2016 at 9:52 am
… Many people do, so you are in good [bad?] company.

Pure ad hominem.

Researchers know where and when the tides are moving ocean water, and with the high-resolution data from the Swarm satellites, they can pick out the magnetic fluctuations due to these regular ocean movements. JPL

The measurements are quite localized. Local salinity matters.

Reply to  commieBob
December 17, 2016 6:40 pm

So, you don’t want to know. As I said there are many other people who don’t want to know about science too.
It is good that knowledgeable scientists and engineers do want to know and to go ahead with this promising technique.

commieBob
Reply to  Willis Eschenbach
December 18, 2016 5:29 am

It is good that knowledgeable scientists and engineers do want to know and to go ahead with this promising technique.

I am one of those. My quibble is not with Robert Tyler et al. He has been working on the magnetic effect of ocean flow for a long time. Here’s a quote from 2003:

The biggest fields were generated, unsurprisingly, in parts of the ocean where the tide is strongest. link

My quibble is with your statement that one may ignore spatial and temporal variations in salinity.

Reply to  commieBob
December 18, 2016 6:30 am

The important point is that variations in global salinity are not tied to the timing of the lunar phase and over time scales of decades will average out, allowed the effect of temperature to be determined. But, as I said, if you close your mind to that, then you’ll miss out on the promise of the method.

commieBob
Reply to  Willis Eschenbach
December 18, 2016 9:14 am

The important point is that variations in global salinity are not tied to the timing of the lunar phase and over time scales of decades will average out, …

The temperature project is led by Robert Tyler and he points out that the strongest signals are where the tides are the strongest. That occurs in estuarine waters where the salinity variation is also the greatest.
The assumption that things will average out requires that the system is linear time-invariant and that’s just not the case here. I see no indication that Tyler et al. are making the assumption. Do you have any evidence they are doing so?

Reply to  commieBob
December 18, 2016 9:40 am

It goes without saying that one should avoid shallow seas and estuarine waters [no-one in his right mind would drag the discussion down to the irrelevance of those areas]. In the open ocean the salinity integrated over all depths varies extremely little, potentially allowing the temperature variation to be determined. In fact both salinity and temperature can be inferred independently. As Sabaka et al. GRL 2016 point out:
” This suggests the possibility of monitoring temporal variations in the magnetic M2 signal continuously […]. This could be valuable in inferring the associated fluctuations in the ocean electrical conductivity, from which variations in temperature and salinity might be inferred”
That is the eminent promise of the method.

commieBob
Reply to  Willis Eschenbach
December 18, 2016 5:33 pm

lsvalgaard December 18, 2016 at 9:40 am
It goes without saying that one should avoid shallow seas and estuarine waters [no-one in his right mind would drag the discussion down to the irrelevance of those areas].

And yet, as far as I can tell, that’s exactly what Robert Tyler did.

As Sabaka et al. GRL 2016 point out: …

Tyler and Sabaka …

… provide a key proof-of-concept of the method by demonstrating that global ocean heat content can be recovered from “noise-free” ocean tidal magnetic signals generated by a computer model.

However …

When they try to do this with the “noisy” observed signals, it doesn’t yet provide the accuracy needed to monitor changes in the heat content.

The technique shows promise as long as they can get a handle on all the confounding factors, especially …

… other ocean movements, like eddies or other tidal components, …

NASA As far as I can tell the annual variation in salinity produces effects in the same order of magnitude as the temperature signal. Also, as far as I can tell, they aren’t ignoring anything, even salinity.
Interestingly, in other work, Sabaka decides LVOC (laterally variable ocean conductivity which is determined by temperature, salinity, and pressure) is too small to worry about. link

Reply to  commieBob
December 18, 2016 6:57 pm

global ocean heat content
By this they mean the open ocean that covers 80% of the seas. As I said: nobody is dumb enough to think that the shallow seas can be used for this or to object that they could be a problem. It is only when we get the low-noise satellite data that the method will work. All this is so blindly obvious [apart from being even explicitly stated] that it hardly merits further education of you.

Carla
Reply to  lsvalgaard
December 13, 2016 7:15 pm

This video may help some of us understand the subject better.
I was, wondering which satellites they were talking about.
The answer SWARM yeah….
https://www.nasa.gov/feature/goddard/2016/earth-s-magnetic-fields-could-track-ocean-heat-nasa-study-proposes
Dec. 12, 2016
Earth’s Magnetic Fields Could Track Ocean Heat, NASA Study Proposes
AGU 2016 Briefing Materials – Earth’s Magnetic Field Could Track Ocean Heat, NASA Study Proposes
As Earth warms, much of the extra heat is stored in the planet’s ocean – but monitoring the magnitude of that heat content is a difficult task.
A surprising feature of the tides could help, however. Scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean.
https://youtu.be/JaBnNdyH4k4
The ocean’s tides cause subtle fluctuations in Earth’s magnetic field that are detected by the European Space Agency’s Swarm satellites. These magnetic field fluctuations could be the key to measuring ocean heat content from space.
Credits: Conceptual Image Lab at NASA’s Goddard Space Flight Center/Matthew Radcliff, producer
Despite the significance of ocean heat to Earth’s climate, it remains a variable that has substantial uncertainty when scientists measure it globally. Current measurements are made mainly by Argo floats, but these do not provide complete coverage in time or space. If it is successful, this new method could be the first to provide global ocean heat measurements, integrated over all depths, using satellite observations.
Tyler’s method depends on several geophysical features of the ocean. Seawater is a good electrical conductor, so as saltwater sloshes around the ocean basins it causes slight fluctuations in Earth’s magnetic field lines. The ocean flow attempts to drag the field lines around, Tyler said. The resulting magnetic fluctuations are relatively small, but have been detected from an increasing number of events including swell, eddies, tsunamis and tides.
“The recent launch of the European Space Agency’s Swarm satellites, and their magnetic survey, is providing unprecedented observational data of the magnetic fluctuations,” Tyler said. “With this comes new opportunities.”
Researchers know where and when the tides are moving ocean water, and with the high-resolution data from the Swarm satellites, they can pick out the magnetic fluctuations due to these regular ocean movements.
That’s where another geophysical feature comes in. The magnetic fluctuations of the tides depend on the electrical conductivity of the water – and the electrical conductivity of the water depends on its temperature……..
My new country route, has satellites just before/after sunset. Now how cool is that. Think the brightest is ISS that I am seeing between Ripon and Berlin.

alcheson
December 13, 2016 11:34 am

Well…. Without a way to actually measure heatcontent if the ocean they will not have a way to calibrate the model… other than by using other models, which means they will be able to get whatever answer they want.

Reply to  alcheson
December 13, 2016 11:41 am

The effect can be calculated from first principles with the only unknown being the ‘heat content’ or temperature if you will. No model needs to be calibrated.

Aphan
Reply to  lsvalgaard
December 13, 2016 12:04 pm

The effect is not what they are looking for. They plan to measure the effect and use it to extrapolate the temperature. How does one measure the temperature of the entire ocean using only the magnetic pull of water on the surface and edges? Salinity of the ocean increases with depth, and temperatures change as currents pass and mix with each other.

Reply to  Aphan
December 13, 2016 12:11 pm

It is not the ‘magnetic pull at the edges’, but the Moon’s gravitational pull [on the entire ocean] that is the driving force.

Reply to  lsvalgaard
December 13, 2016 12:08 pm

Averaged over the entire ocean the only variable is the temperature.

Reply to  lsvalgaard
December 13, 2016 12:53 pm

lsvalgaard December 13, 2016 at 11:41 am Edit

The effect can be calculated from first principles with the only unknown being the ‘heat content’ or temperature if you will. No model needs to be calibrated.

I don’t believe that for a moment. As far as I can see there is no path using only “first principles” from a 2D satellite measurement of variations in magnetism to a 3-D temperature map of the ocean, particularly given the confounding variables (salinity, pressure, geomagnetic variations, solar wind variations, heliomagnetic variations).
How do you plan to do that without using any calibrated models?
w.

Reply to  Willis Eschenbach
December 13, 2016 1:04 pm

I’m not talking about a MAP, but of the GLOBAL effect.
The physics is quite simple: the conductivity depends on number of ions and the temperature. The movement of the water depends on the tidal forces of the Moon [which can be computed precisely]. The induction of current depends on the conductivity, the movements, and the magnetic field [which is known]. The magnetic effect of a current can be easily calculated and also measured. Vary the [unknown] temperature until the calculated and observed effects match and you have an estimate of the temperature.

Reply to  lsvalgaard
December 13, 2016 1:53 pm

lsvalgaard December 13, 2016 at 1:04 pm

I’m not talking about a MAP, but of the GLOBAL effect.
The physics is quite simple: the conductivity depends on number of ions and the temperature. The movement of the water depends on the tidal forces of the Moon [which can be computed precisely]. The induction of current depends on the conductivity, the movements, and the magnetic field [which is known]. The magnetic effect of a current can be easily calculated and also measured. Vary the [unknown] temperature until the calculated and observed effects match and you have an estimate of the temperature.

I understand that. Let me take it a bit at a time.

The physics is quite simple: the conductivity depends on number of ions and the temperature.

No. It depends on temperature, the salinity, and the pressure. All of these vary over space, time, or both.

The movement of the water depends on the tidal forces of the Moon [which can be computed precisely].

The movement of the ocean water, both horizontal and vertical, does indeed depend on “the tidal forces of the Moon [which can be computed precisely]”. However, while we can measure the forces exactly, the horizontal and vertical ocean movements vary wildly in both time and space, at a wide range of spatial and temporal scales, and are in principle NOT calculable from said tidal forces. For example, the satellite measurements of sea levels have revealed many surprises which are not calculable from lunar first principles.

The induction of current depends on the conductivity, the movements, and the magnetic field [which is known].

Yes, but the conductivity and the movements are NOT known. In general, we don’t know either the speed, salinity, or the temperature of the ocean currents at point X in the 3-D ocean.

The magnetic effect of a current can be easily calculated and also measured.

Indeed … but you are effectively doing an MRI of the globe. We know the magnetic variations out on the outside of the body in question, either a person or the global ocean. From that we are trying to reconstruct what is actually happening inside of the body, either the person or the ocean. I deny categorically that you can do that without a computer model, any more than you can do an MRI without a computer model.

Vary the [unknown] temperature until the calculated and observed effects match and you have an estimate of the temperature.

First, we don’t have the observations on the deep half of the ocean needed to do this matching. Argo floats only sample the top 2km at max, and most of them only 1 km down. Below that we don’t know much.
Next, temperature is not the only unknown—salinity and current velocity are not known either. So this procedure has more unknowns than we have equations …
My thanks as always for your thoughts,
w

Reply to  Willis Eschenbach
December 13, 2016 2:05 pm

I deny categorically that you can do that without a computer model, any more than you can do an MRI without a computer model.
Gauss showed how to do this [separate internal and external contributions] back in the 1830s…
And without a computer 🙂
What I said was that the conversion from magnetic effect to electric current to conductivity is not based on empirical calibration, but on fundamental physics. The mechanics of actually doing the determination of the global temperature is definitely a challenge, but should be doable, so the thing has promise.
Not too long ago, it was thought that we could not determine the magnetic field in interplanetary space centuries ago. Today we can. Don’t underestimate what is possible if the physics is correct.

aaron
Reply to  lsvalgaard
December 13, 2016 2:10 pm

If we are just looking for a global average, I don’t see it likely being useful. Couldn’t hurt to see what we see.
Maybe if we have consistent and calibrated data collection, we’ll see some interesting patterns over the millennia.

Reply to  aaron
December 13, 2016 2:13 pm

If we are just looking for a global average, I don’t see it likely being useful
Yet people are obsessing about the global temperature trend or SST trend, etc.
Because you cannot see something does not mean that others cannot either.

Reply to  lsvalgaard
December 13, 2016 2:59 pm

Willis:
I don’t think we need the detailed knowledge of flows, salinity, etc at every 3D point in order to determine the average values over the globe. The average will vary but little varies over time, as the topology and other local effects don’t vary on the time scales of interest. In short, I think that the technique has merit, even though it may take us some effort [and time] to put it into practice. I also think that no empirical calibration [“curve fitting”] is needed as the physics is known.

Reply to  lsvalgaard
December 13, 2016 4:02 pm

Lief, The concept is sound, develop it.
[before you lecture him, how about learning to spell his name first? -Anthony]

Reply to  Sparks
December 13, 2016 9:46 pm

In Dutch [which is often spoken at my home] ‘Lief’ means ‘dear’…

Reply to  lsvalgaard
December 14, 2016 12:50 pm

When have I ever Lectured my Lief 😉 apologies for the typo Leif.

Reply to  lsvalgaard
December 13, 2016 5:41 pm

lsvalgaard December 13, 2016 at 2:59 pm

Willis:
I don’t think we need the detailed knowledge of flows, salinity, etc at every 3D point in order to determine the average values over the globe. The average will vary but little varies over time, as the topology and other local effects don’t vary on the time scales of interest. In short, I think that the technique has merit, even though it may take us some effort [and time] to put it into practice. I also think that no empirical calibration [“curve fitting”] is needed as the physics is known.

I don’t understand this. All parts of the ocean have different velocity, different salinity, different pressure, and different temperature. I don’t think we can even determine the average values of all of those close enough to do what you think you can do.
Time will tell whether it is doable at all … my question about floor to ceiling uncertainties remains.
Thanks as always for your detailed and interesting answers,
w.

Reply to  Willis Eschenbach
December 13, 2016 8:51 pm

Reasonable attempts have been made a long time ago by determining the coefficients of an expansion in spherical harmonics, e.g. Malin and Chapman in the 1970s. The point is that the average conditions [ocean topology, currents, tides, salinity, etc] are relatively stable, while temperatures might vary. Assume a steady global warming, that would increase conductivity steadily and so would the ocean effect, which may be measurable. Thus giving us an independent check on things. In my opinion, this is a viable method. It needs to be done, of course.

tty
Reply to  lsvalgaard
December 24, 2016 1:25 am

“The point is that the average conditions [ocean topology, currents, tides, salinity, etc] are relatively stable, while temperatures might vary.”
Actually all these vary significantly, and on timescales comparable to the lunar cycle. Ever hear of ENSO? Monsoons? Agulhas spillover? Large-scale eddying? Wind-induced upwelling? Hurricanes?

rocketscientist
Reply to  alcheson
December 13, 2016 1:45 pm

When you only have one data point the curve can go any direction you like. When you have no data points the curve is merely a doodle.

H. D. Hoese
December 13, 2016 11:55 am

You do have to adjust a conductivity meter for temperature, but it is mostly salinity. I suggest that they try a test case in the Gulf of Mexico, screwy tides, mostly wind driven currents, messed up by the Loop Current which throws eddies, Mississippi floods, etc., etc., etc.

Reply to  H. D. Hoese
December 13, 2016 12:01 pm

I think the approach is best suited for a GLOBAL solution. With the goal of determining the GLOBAL ocean temperature. With satellites we can measure the GLOBAL magnetic effect [also from the GLOBAL network of geomagnetic observatories – albeit with less accuracy].

RH
Reply to  H. D. Hoese
December 15, 2016 12:36 pm

I suggest they try a test case in a fish tank.

Smart Rock
December 13, 2016 11:58 am

They are seriously proposing this at a conference of geophysicists?
How will they separate the noise from the oceanic crust? Which everyone who has even the slightest contact with earth science (used to be called geology) is intimately familiar with. Here’s a shot of the magnetic field in the north Atlantic as an example.
http://geomag.org/models/WDMAM/NW_atlantic.jpg

Reply to  Smart Rock
December 13, 2016 12:02 pm

Because the tidal effects vary on a very precise time schedule, while the crustal field does not.
Scientists are not morons.

Bob Boder
Reply to  lsvalgaard
December 13, 2016 12:13 pm

I know a few that are.

Reply to  Bob Boder
December 13, 2016 12:17 pm

Pretty severe charge. Name them.

catweazle666
Reply to  lsvalgaard
December 13, 2016 12:14 pm

“Scientists are not morons.”
Hmmmm…

Reply to  lsvalgaard
December 13, 2016 1:57 pm

Because the tidal effects vary on a very precise time schedule, while the crustal field does not.
Scientists are not morons.

Yes Dr Svalgaard some people who call themselves scientists really are, unfortunately.

lsvalgaard December 13, 2016 at 12:17 pm
Pretty severe charge. Name them.

Well I can name some. Dennis M. Bushnell, Chief Scientist at NASA Langley Research Center, for a start.
https://en.wikipedia.org/wiki/Energy_Catalyzer

Other reactions to the device have been mixed. In 2011 Dennis M. Bushnell, Chief Scientist at NASA Langley Research Center, described LENR as a “promising” technology and praised the work of Rossi and Focardi

And some more

Giuseppe Levi
Bologna University, Bologna, Italy
Evelyn Foschi
Bologna, Italy
Bo Höistad, Roland Pettersson and Lars Tegnér
Uppsala University, Uppsala, Sweden
Hanno Essén
Royal Institute of Technology, Stockholm, Sweden

And don’t forget Tim Flannery, the man who, by his own admission, wasn’t bright enough to get into an undergraduate science degree course so did a degree in English Literature. Who also(see ‘two men in a tinny’) believes in Gaia(there is no such thing), and that “our intelligence was put here for a purpose”(bollocks).
Tim Flannery also caused the deaths of children through the economic destruction caused by the wasted expenditure, of circa ten billion dollars, on the white elephant desalination plants in Australia.

Reply to  acementhead
December 13, 2016 2:08 pm

Being wrong is not being moronic…
Being wrong is every good scientist’s prerogative.
E.g. Einstein on Quantum Mechanics.

Reply to  lsvalgaard
December 14, 2016 1:01 pm

lsvalgaard December 13, 2016 at 2:08 pm
Being wrong is not being moronic…
Being wrong is every good scientist’s prerogative.
E.g. Einstein on Quantum Mechanics.

Well I disagree. You are effectively saying that the statement “No scientist can be shown to be a moron.” is unfalsifiable. Not very scientific. If a scientist is wrong over and over again, on simple things, then he is ipso facto a moron.
It’s OK to be wrong about CO2 freezing out of the atmosphere at -56 C. That doesn’t show moronity, just a lack of due care. Flannery does much worse over and over.

rd50
December 13, 2016 12:12 pm

This is simply advertising from NASA.
Look at the end of the video:
“The planet is changing. We’re on it”
And look at the top “Share”. Indeed send the ad to all your friends.

RH
Reply to  rd50
December 15, 2016 12:52 pm

Yep, what rd50 said. It probably won’t save their jobs, unless they happen to have skills transferable to space exploration. 1/20/2017 can’t get here quick enough.

tomo
December 13, 2016 12:33 pm

Leader of OCO-2 Science Team – pre-launch lecture

rd50
Reply to  tomo
December 13, 2016 2:31 pm

tomo. Thanks for the link
No question about it.
A great lecture by David Crisp.
He is a scientist.
We should be proud to have him at NASA.
Measurements, not predictions.
His interaction with the audience on comments/questions was just superb.
Also, in his lecture he is very good at anticipating important questions, for which we have no specific answer yet. This is very good and honest. Don’t wait for the audience to ask these questions, anticipate them and honestly answer.

Thomas Homer
December 13, 2016 1:07 pm

From the article:
“The resulting magnetic fluctuations are relatively small”
NASA’s ability to measure “relatively small” magnetic fluctuations of ocean water may be a worthy pursuit, but why isn’t NASA measuring the heat trapped by the Mars’ 95% CO2 atmosphere? Is Mars’ heat hiding as well? Is it un-measurable or just insignificant?

Reply to  Thomas Homer
December 13, 2016 1:33 pm

NASA’s ability to measure “relatively small” magnetic fluctuations of ocean
The effect has been measured a century ago. Not difficult as the signal is VERY sharply timed by the Moon.

rd50
Reply to  lsvalgaard
December 13, 2016 2:57 pm

OK.
Give me some help.
Give me a link to find this measurement.
Thank you

jmorpuss
December 13, 2016 1:08 pm

“What’s the connection between electricity and heat?
NASA Machined Copper CGR-84 Thruster #GRC-C07-VPS (Vacuum Plasma Spray).
Photo: Copper conducts heat and electricity equally well. Photo courtesy of NASA Glenn Research Center (NASA-GRC).
Have you noticed that when we talk about conduction in science we can be referring to two things? Sometimes we mean heat and sometimes we mean electricity. A metal like iron or gold conducts both heat and electricity really well; a material like a plastic doesn’t conduct either of them very well at all. There is a connection between the way a metal conducts heat and the way it conducts electricity. If you’ve read our main article on electricity, you’ll know electric current is carried through metals by tiny charged particles inside atoms called electrons. When electrons “march” through a material, they haul electricity with them a bit like ants carrying leaves. If electrons are free to carry electrical energy through a metal, they’re also free to carry heat energy—and that’s why metals that conduct electricity well are also good conductors of heat. (Things aren’t quite so simple for nonmetals, however, because heat travels through them in other, more complex ways. But for the purposes of understanding thermocouples, metals are all we need to consider.)”
http://www.explainthatstuff.com/howthermocoupleswork.html

jmorpuss
December 13, 2016 1:27 pm

EMF stands for Electromotive force or electromagnetic field. If you have a electric field it will induce a magnetic field , if you have a magnetic field it will induce a electric field.
” So far we’ve dealt with electricity and magnetism as separate topics. From now on we’ll investigate the inter-connection between the two, starting with the concept of induced EMF. This involves generating a voltage by changing the magnetic field that passes through a coil of wire.”
http://physics.bu.edu/~duffy/PY106/InducedEMF.html

December 13, 2016 2:15 pm

Earths conductive oceans are being tracked by every means possible, what is also being tracked is the interpretation.

Ryan
December 13, 2016 6:39 pm

Has anyone tried to correlate the earths meandering magnetic poles in approximation to the earths axis with the earths climate changes? I have not seen any study on this yet. Since magnetism affects water like combing your hair to put static on a comb and putting close to a stream of water coming out of a faucet and it pulls the water toward the comb. On and earth scale does the electromagnetic poles affect weather patterns?

December 13, 2016 6:53 pm

If Lief says it could work, I’ll go with that. But I have a problem with the statement, “As Earth warms, much of the extra heat is stored in the planet’s ocean…” If the extra heat is from the Sun’s rays penetrating the oceans, i.e. with no impediment from clouds, etc., OK. But from LWIR, NO.

jmorpuss
December 13, 2016 9:24 pm

Could it be what their actually measuring is evaporation. Because the oceans conduct electricity does it split the week bond between hydrogen and oxygen, like in this video.https://www.youtube.com/watch?v=wwGx7qqQe-Y

Reply to  jmorpuss
December 13, 2016 11:38 pm

No, they are measuring the magnetic field caused by the electric current induced in the conducting sea water by the tidal force of the Moon moving the water across the Earth’s magnetic field.

jmorpuss
Reply to  lsvalgaard
December 14, 2016 3:45 pm

Lief , There are other things that move sea water around besides the moon .
“Most people grow up thinking that the tides are caused by the moon, and indeed that gravitational ‘pull’ of the moon is a major factor, as is the gravitational effect of the sun but there is another major factor, which is less often mentioned, and that is the force created by the rotation of the earth itself.”
http://www.astronomyknowhow.com/moon-tides.htm
“Although it is often asserted that the moon “controls” the tides, this is really an oversimplification of the tidal system. In fact there are many factors which determine the tides, including the moon, the sun, the rotation of the earth, the geomorphology of the ocean basin, and the location of the particular spot where you’re measuring the tide along that basin. All of these factors interact in a complex way to determine the specifics of the tide’s characteristics at each location on Earth. ”
http://scienceline.ucsb.edu/getkey.php?key=353
“Besides the natural daily variation in tide due to the gravitational effects of the moon, sun and other planets, there’s one more lesser known but major contributing factor to the current sea level.”
http://www.swellnet.com/news/swellnet-analysis/2016/04/19/inverse-barometer-effect

Reply to  jmorpuss
December 15, 2016 8:12 am

None of this matters [and besides, the pressure is also influenced by the Moon] as they are not tied to the very precise timing of the lunar phase. By locking the effect to the precise lunar phase you isolate that part which is directly run by the Moon.

Macha
December 14, 2016 1:33 am

Sounds like looking at an elephant through a microscope to me…..

Johann Wundersamer
December 16, 2016 4:44 am

From the “Thermometers? We don’t need no steenkin thermometers!”
Well, all began with stinking Thermometers.

December 16, 2016 10:06 am

Electricity through resistance causes heat. Which came first, the heat or the electric current ? And how much ? It’s a water world of about 70%. And is it voltage or current ? I know there are going to tell me it’s so small it doesn’t have any effect. Sure, you’re going to measure an electrical impulse over thousands of miles thats so small it doesn’t have any effect. Saltwater does conduct, but not like copper. And of nothing in the earth’s magnetic field is connected to anything in space…. I’ve been told that the ” total amount of energy wouldn’t melt a snowflake ” . Of course, nobody sticks a fork in a microwave oven when it’s running, or runs a ground out of it or a magnetic waveguide. Nothing to shape the extent or size of a radio field.

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