This comment seemed like a useful question to discuss, so I’m elevating it to post status
I see ocean heat content discussed here and elsewhere from time to time, but I have never seen a discussion of what causes it to increase. The clear implication is that it is increasing because of warmer atmospheric surface temperatures, but that makes no sense to me.
Surely the small increase in warming of the atmosphere to date could not transfer a significant amount of heat to the oceans. It seems obvious to me the only way that the oceans could accumulate much heat would be through direct heating from solar radiation. If that is occurring, wouldn’t that be direct evidence of a decrease in cloud cover, instead of evidence for AGW?
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AIR•For higher accuracy – a value of cp = 1.006 kJ/kg.K (equal to kJ/kg.oC)
The average mass of the atmosphere is about 5 quadrillion (5×1015) tonnes
SALT WATER Specific heat capacity, Cp . . . . . . . . . .
3985 J kg−1 K−1
3993 J kg−1 K−1
The total mass of the hydrosphere is about 1,400,000,000,000,000,000 metric tons (1.5×1018 short tons)
How is something (air) that has 1/4 the heat capacity and 3 orders of magnitude less mass going to heat the oceans?
Sunshine works for me.
I think that wind patterns can affect ocean temperatures.I know that air does not hold as much heat as water but it does circulate faster than ocean currents and can transfer heat/cold around over a period of time,we saw this during the recent blocking in the North Atlantic when the the normal west winds were replaced by cold winds from the North and the North sea gradually cooled.
Global ocean-warming is not an atmospheric but a plate tectonic phenomenon. From the 1830s on, worldwide deep-ocean basins from the Arctic to Atlantic and Pacific have been subject to increasing “large magmatic episodes,” that is, the opening of extreme high-temperature vents surrounding continental landmasses at their margins.
On this basis, we hypothesize that since Planet Earth is not merely an oblate spheroid but very slightly “pear-shaped,” minuscule instabilities cause Gaia to wobble geophysically, expand and contract by a factor of about half a mile (or less) on her 4,000-mile equatorial radius, ie. by ~.0125% (1.25 parts per 100,000).
Geophysical effects tied to Earth’s marginally skewed departure from sphericity are the parsimonious explanation for observed bathymetric warming over nigh 175 years. Try submitting a grant application to depict and interpret this phenomenon in detail, and see how far you get.
Roy Clark says:
May 11, 2011 at 8:30 am
I agree with Roy that extra warmth in the air from more downward infra red radiation or from warmer air above cannot significantly warm the ocean bulk due to an increased rate of evaporation and the net cooling effect of the evaporative process.
I have been saying as much in various blogs for several years now.
However Roy then goes on to say that the changes in solar irradiance are sufficient to achieve the observed changes in ocean heat content over time. I am more doubtful about that because proportionately the solar changes are very small so long periods of time would be involved yet we have seen changes in ocean heat content occur quickly.
Thus I prefer the changes in cloudiness and albedo as the primary cause over short to medium timescales with solar variations other than raw TSI being responsible for shifts in the air circulation systems.
It is nice to see these topics being taken more seriously now. I have up to now felt out in the wilderness against overconfident AGW proponents and certain solar ‘experts’ who deny any solar involvement in climate changes.
I’m not a scientist, but an experienced life guard. I work at a city pool. On a sunny 90 degree summer day the pool is about 10 degrees warmer than it is on a cloudy 90 degree summer day.
The pool temp is taken at the surface. At what depth is ocean temperature taken?
This one is pretty simple to answer and the concept can be used for a science fair project for younger grade school students. When I was a kid, we used to make what we called sun tea. All that was needed was a glass container, water, and a few tea bags (of course, a couple mint leaves from the mint patch added just the right flavor enhancement!). When put out in the sun for a couple of hours, the water would heat enough to steep the tea and by dinner time, the tea would be ready. Place that same concoction in a shady area and you were out of luck. The tea would always have a higher temperature than the ambient air temp, so obviously the sun was heating the liquid more than the air temp. The one left in the shade would not always reach ambient air temp, though it would if left out there long enough. Regardless, the change in temp always occurred MUCH faster for the one in the sun than the one in the shade. Now, there are aspects of the physics of it all with the closed glass containers and all, but it became quickly obvious to me that the sun can heat much more and much faster than the air.
What a wonderful post this is. Only WUWT has achieved a level of clarity that permits answering commonsense questions while fully respecting the scientific background.
My approach to these questions is from scientific methodology. I’ll try to be brief. There is no known physical mechanism that would explain how the atmosphere can heat the ocean.
As regards the Sun, there is a physical mechanism that can explain in general that radiation from the Sun does heat the oceans. However, no one has been able to formulate hypotheses based on this physical mechanism that enables prediction of the temperature changes in the oceans that we care about. In other words, no one has been able to rigorously formulate a set of physical hypotheses that explain the behavior that we want to explain.
Voila! At this time, there is no physical science that enables explanation or prediction of the changes in ocean temperature that we wish to explain and predict. Warmista know this fact. That’s why all they offer are model runs and various collections of “temperature data” from proxies or whatever. Among all the Warmista, there is not one physical hypothesis that could serve to explain and predict ocean temperature changes. Yet they claim to be scientists. They would do better to claim to be Al Gore.
If science is to produce a physical explanation of the ocean temperature changes that we care about then the first step is that scientists must describe the natural regularities upon which these temperature changes ride. To take an easy and familiar example, if we are to explain the temperature changes associated with La Nina then scientists must first identify and describe the physical processes occurring in the ocean, in the atmosphere, and at the boundary during the course of a La Nina event.
Unfortunately, no one has ever attempted to describe the physical processes that make up La Nina. Much to their discredit, Warmista dogmatically claim that La Nina is statistical noise rather than a physical process. Others are happy to look at the temperature numbers associated with La Nina and call that a science. Of course, temperature numbers are no less in need of explanation through use of physical hypotheses than are the phenomena.
Briffa is an excellent example of this point. After his tree rings began declining in 1960, he had no idea why they declined. Was it because of temperature? Moisture? Something else? Without a set of physical hypotheses which explain how the tree rings respond to changes in temperature, moisture, and everything else that affects them, the numbers that come from temperature readings are worthless.
Let us all learn this one important lesson. In science, physical hypotheses that are not rigorously formulated and specify no data (particular phenomena that we care about) are useless. Data that are not explained by some physical hypotheses are unorganized nonsense.
With the exception of Arrhenius’ CO2 hypotheses, today’s climate science has no physical hypotheses. Arrhenius’ hypotheses predict warming or cooling depending on the feedbacks from increased CO2. Yet no one has physical hypotheses which explain one or more feedbacks. Once the physical science of feedbacks are known, Arrhenius’ hypotheses predict nothing for Earth’s climate. Climate science will not advance out of infancy until climate scientists give up the computer models, the statistical arguments, and get into the field and develop techniques for detecting and describing the natural regularities that govern such phenomena as cloud formation, La Nina, and other wonderful things to study.
Nicola Scafetta addresses the different rates at which the atmosphere and ocean react, as well as evidence for solar driven climate change. e.g.
Empirical analysis of the solar contribution to global mean air surface temperature change
“Empirical evidence for a celestial origin of the climate oscillations and its implications”. Journal of Atmospheric and Solar-Terrestrial Physics 72, 951–970 (2010), doi:10.1016/j.jastp.2010.04.015 PDF
Solar/planetary modulation of magnetic fields when modulate cosmic rays which modulate clouds when change albedo/solar absorption is one model increasingly being studied by researchers.
Hundreds of thousands of new undersea volcanoes have recently been discovered [millions, if volcanoes under 300 meters height are counted]. For some unknown reason, the number of undersea volcanoes is far out of proportion to the number of land-based volcanoes.
Surely these undersea volcanoes must have some effect on OHC.
This is weird.. some of the comments, I mean.
Evaporation cools water surface. Ever jump into an unheated pool in the desert SW on a 95 degree afternoon?
Seems to me that heat from that pool isnt lost, it’s added to the air around it by the vapor. Yep, heat goes from lower to a higher temp molecule. But that’s just a hunch and assumes LW IR radiation.
Try heating your tea water with a hairdryer blowing on the water surface. THEN try aiming your hairdryer on the side of the pan.
The only way temp can transfer close to efficiently from air to water is at 100% RH. And it’s STILL by LW IR, I would think.
_________________________________
“Half of CO2 absorbed heat” does NOT go back to the surface. The earth is still a GLOBE, is it not?. I’m not a scientist or anything but seems to me the higher in altitude the GHG, the less LW IR makes it back to the surface and it ALL ultimately ends up in space.
But that’s just my guess.
Sea drives land.
A 2008 study – “Oceanic Influences on Recent Continental Warming”, by Compo, G.P., and P.D. Sardeshmukh, (Climate Diagnostics Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado, and Physical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration), Climate Dynamics, 2008)
[http://www.cdc.noaa.gov/people/gilbert.p.compo/CompoSardeshmukh2007a.pdf] states: “Evidence is presented that the recent worldwide land warming has occurred largely in response to a worldwide warming of the oceans rather than as a direct response to increasing greenhouse gases (GHGs) over land. Atmospheric model simulations of the last half-century with prescribed observed ocean temperature changes, but without prescribed GHG changes, account for most of the land warming. … Several recent studies suggest that the observed SST variability may be misrepresented in the coupled models used in preparing the IPCC’s Fourth Assessment Report, with substantial errors on interannual and decadal scales. There is a hint of an underestimation of simulated decadal SST variability even in the published IPCC Report.”
This document describes the El Nino / Southern Oscillation (ENSO).
Those interested in the Team’s take on this should Google ‘why the blip’ and see how the problem was smoothed away by an arbitrary adjustment when this simple truth got in the way of the narrative.
JF
It’s the Kriegesmarine effect. Betcha. But not a lot.
Of course much of varied temperatures are caused by heat transfers but from water movement. I.e., the thermometer is stationary but the water is not, being in constant circulation.
A. Patterson Moore:
Sorry I missed your OHC question over on the UAH update thread. Natural factors can be shown to be the primary cause of the rise in global ocean heat content. These include the El Nino-Southern Oscillation (ENSO), changes in sea level pressure, and multidecadal variability due to processes such as Atlantic Meridional Overturning. I illustrated these in posts over the past couple of years that Anthony cross posted here at WUWT. They include:
http://bobtisdale.wordpress.com/2009/09/05/enso-dominates-nodc-ocean-heat-content-0-700-meters-data/
AND:
http://bobtisdale.wordpress.com/2009/12/30/north-pacific-ocean-heat-content-shift-in-the-late-1980s/
AND:
http://bobtisdale.wordpress.com/2009/10/04/north-atlantic-ocean-heat-content-0-700-meters-is-governed-by-natural-variables/
Regards
Plate tectonic’s heat contribution is potentially huge. The water emanating from a ‘black smoker’ approaches 700 degrees C…and doesn’t boil due to the immense seafloor pressure. The mid-ocean ridge system is the world’s longest mountain range, at some 40,000 miles…some segments more active in spreading than others. Anomalous blisters like Iceland must be huge contributors. And what about CO2 contribution!
The sea is at about 290K on average. It has a very high emissivity so it is radiating a huge amount of long wave energy upwards. Some of this is lost directly to space and some warms the atmosphere. It is also losing a lot of energy to the atmosphere through evaporation (particularly in windy conditions). There is some cooling by conduction and subsequent convection but it is small because the air close to the surface is at roughly the same temperature.The reason it does not cool continuously is that for some part of every 24 hours (except in the arctic/antarctic circles) it gets a huge burst of short wave energy from the sun. It also gets a smaller amount of long wave radiation from the atmosphere day and night.
Sea temperature averaged over the globe and over the year is pretty constant so the losses and the gains are pretty much the same. We are roughly in energy balance. If this balance is lost the sea will either warm or cool. This can happen locally and at the surface but to heat or cool the bulk of the oceans significantly would take a very long time.
There is no doubt that the vast majority of the energy absorbed by the sea is in the form of the direct short wave insolation. However small changes in the energy balance can come from anywhere. We can change the insolation at the top of the atmosphere we can change the albedo of the clouds or of the sea surface, we can change the relative amount of UV (active sun) which may effect ozone or the depth at which absorption in the sea takes place, we can change the evaporation rates. Or we can change the amount of heat radiated from the atmosphere, which is what the “models” do. There is nothing intrinsically wrong with this latter hypothesis. Indeed as the warmists continuously point out the science supports such a possibility.
So although it is a good question the answer is not really helpful. We are still in the situation of trying to decide whether there is a change in ocean heat content and, if there is, which of the many possibilities is the cause. As I have said before trying to argue that CO2 cannot be the cause is as silly as saying that it is the only possible cause.
However the actual cause of the imbalance should leave a signature. Increased atmospheric warming (say due to CO2) should be detectable day and night and winter as well as summer. Increased insolation or reductions in cloud cover should lead to greater peak temperatures in summer. However the caotic nature of the system makes such signatures very difficult to read.
For what it is worth my personal view is that the OHC plateau in the last 9 years suggests that, during this period, we have been in energy balance. That suggests that even if CO2 can be shown to be the cause of the previous imbalance its effect has already been neuralised by the surface temperature increase we have already experienced. This puts an upper limit on any CO2 effect and places it in the “why worry” category. That is assuming you are one of those who believe this is the best of all possible worlds and any change is for the worse. I personally would welcome another degree or so of warming in the winter and at night.
Why greenhouse gases won’t heat the oceans:
http://hockeyschtick.blogspot.com/2010/08/why-greenhouse-gases-wont-heat-oceans.html
When a clean water body is viewed from directly above with the Sun behind — that ocean surface appears black. Something of this nature is seen in the image linked below. (I did not find the explanation of the color for this image.)
http://esamultimedia.esa.int/images/EarthObservation/images_of_the_week/Somaliland_MER_RR_Orbit15691_20050301_HI.jpg
Envisat’s Medium Resolution Imaging Spectrometer (MERIS) acquired this image on 1 March 2005. Posted 14 April 2006 – 12:37 PM
Earth from Space: The Gulf of Aden
http://www.unexplained-mysteries.com/forum/index.php?showtopic=66800
An absence of returning wave lengths give the appearance of black. Earth is called the “blue” planet because of its atmosphere even though maps and globes provide, falsely, the notion of a blue ocean.
Views from space show a lot of energy entering the world’s oceans.
Nobody has ever warmed his bathwater by switching on the radiator’s bathroom.
bob says:
May 11, 2011 at 7:55 am
but measured trends show a decrease in relative humidity, and increase in specific humidity
Source?
According to NOAA satellite data, both relative and specific humidity are on a downtrend:
http://www.climate4you.com/GreenhouseGasses.htm
It seems to me that it is all about water. Not only the ocean liquid component and the cloud vapor component but also humidity that is still there on a clear sunny day. The relative humidity probably at various levels of the atmosphere.
In measuring incident solar levels at different solar furnaces where I worked for several years (all of which were in the desert of New Mexico about 32 deg N), I noticed that incident levels on clear sunny days varied dramatically from day to day, week to week, and season to season. These levels were generally correlated to surface humidity levels but it would be interesting to see how balloon sonde data through higher altitudes might affect the values. Low humidity produced higher incident solar readings. Summers in the desert are very warm and and often during the monsoon periods humidity in the mornings is very high. Afternoon cloudiness with thunderstorms of course would drop incident solar input to very low to generally non existent levels. Peaks (at solar noon) for solar surface readings during the long hot humid days of summer were often only 850 watts per m^2.
On clear dry fall days solar surface readings were often as high as 1050 watts per m^2. It is interesting to hear about CO2 forcing a few watts per m^2 while water in it’s “clear” vapor form (not clouds) seems to affect short wave incident solar radiation to the tune of up to 200 watts per m^2. This may only happen in desert areas but it is a very measurable day time effect of atmospheric (and stratospheric?) water vapor.
Variation in humidity patterns over 60 to 100 years would help explain part of the long term natural climate cycles that we have started to identify during our emerging insight over the past 10 or 15 years. Perhaps driven in part by small long term variations in day time surface solar incident values?
Bernie
new paper out today relevant to the OHC discussion:
http://hockeyschtick.blogspot.com/2011/05/new-paper-explains-another-way-that.html
The specific heat of water (volumetric heat capacity) is about 3,200 x that of air, so the heat-exchange capability of air to water is miniscule.
The law of the blobs in an upside down slimy bugger lamp.
Consider a one square metre column of air over ocean water. The mass of that air will be about 10,330 kilograms. The specific heat of that mass of air will be the same as just 2.6 metres of ocean water under it. The oceans on average are much deeper than 2.6 metres. There is no way the atmosphere can heat the ocean. IR radiation in the range 3 to 100 microns does not penetrate water to more than a millimetre. Sunlight and especially UV can penetrate to 100 metres or so. Now that can heat a volume of water, not just the surface. Put a cloud in the way of the sun and that deep heat stops. James Lovelock pointed out back in the 1970s that phytoplankton will release DMS gas if they find the water too warm. This gas is an excellent cloud condensation nuclei. Those little beasties learned billions of years ago how to make a sunshade if things got too warm.
“Atmospheric CO2 absorbs radiative heat energy coming from below that would otherwise go out into space quickly. The CO2 re-emits this energy – half of which goes back down. The oceans absorb much of this. This extra energy heats the oceans and will eventually heat the atmosphere and will eventually go back out into space.”
This bolded portion seems questionable and overly simplistic to me. Assuming that the CO2 molecule re-radiates this heat equally in all directions, you get 360° of radiation. The 180° “half” do not all lead “down” to the ground. There’s a whole lot of “sideways” that you are assuming eventually makes it “down,” instead of outwards, and ultimately “up” back into space. Depending on the altitude of the subject molecule, the slice of its complete field-of-view occupied by the Earth’s surface would vary greatly. I would generously guess that this “one-half” estimate should be lowered to somewhere around “one-third.”
Heh. Since the Earth is a globe, you have some significant “round-ing bias” indeed.