A paper published August 20th in Geophysical Research Letters finds from newly deployed observation systems that the Southern Oceans show an annual net heat loss of -10 Wm-2.
Key Points
- Southern Ocean air-sea fluxes are under-observed, leading to large uncertainty
- The first year-long air-sea flux observations quantify an annual cycle
- Shows seasonal cycle, small annual net ocean heat loss and extreme events
Due to a previous “paucity of reference observations”, this paper is the first to study annual heat flux between the atmosphere and the Southern Oceans, a “key component of the global climate system: insulating the Antarctic polar region from the subtropics, transferring climate signals throughout the world’s oceans and forming the southern component of the global overturning circulation.”
That finding contradicts claims that the oceans are gaining ‘missing heat’ due to an increase in greenhouse gases. For example, The figure below from Bob Tisdale compares the ARGO-era Ocean Heat Content observations to the model projection, which is an extension of the linear trend determined by Hansen et al (2005), for the period of 1993 to 2003. Over that period, the modeled OHC rose at 0.6 watt-years per year. With the recent seasonal declines in Global Ocean Heat Content anomalies, the model projection is rising at a rate that’s more than 10 times higher than the observations since 2003. 10 times higher. Yet the southern ocean has just been demonstrated to be losing heat.
Here is the paper:
First air-sea flux mooring measurements in the Southern Ocean
GEOPHYSICAL RESEARCH LETTERS, VOL. 39, L16606, 8 PP., 2012
doi:10.1029/2012GL052290 E. W. Schulz, S. A. Josey, and R. Verein
The Southern Ocean is a key component of the global climate system: insulating the Antarctic polar region from the subtropics, transferring climate signals throughout the world’s oceans and forming the southern component of the global overturning circulation. However, the air-sea fluxes that drive these processes are severely under-observed due to the harsh and remote location. This paucity of reference observations has resulted in large uncertainties in ship-based, numerical weather prediction, satellite and derived flux products. Here, we report observations from the Southern Ocean Flux Station (SOFS); the first successful air-sea flux mooring deployment in this ocean. The mooring was deployed at 47°S, 142°E for March 2010 to March 2011 and returned measurements of near surface meteorological variables and radiative components of the heat exchange. These observations enable the first accurate quantification of the annual cycle of net air-sea heat exchange and wind stress from a Southern Ocean location. They reveal a high degree of variability in the net heat flux with extreme turbulent heat loss events, reaching −470 Wm−2 in the daily mean, associated with cold air flowing from higher southern latitudes. The observed annual mean net air-sea heat flux is a small net ocean heat loss of −10 Wm−2, with seasonal extrema of 139 Wm−2 in January and −79 Wm−2 in July. The novel observations made with the SOFS mooring provide a key point of reference for addressing the high level of uncertainty that currently exists in Southern Ocean air-sea flux datasets.
Here are two additional figures from the paper: wind speed
Surface variables and heat flux:
h/t to The Hockey Schtick
We all know that the heat accumulates in the Hadley Heat Hidey Hole which was discovered by Al Gore while snorkeling off the coast of Cabo San Lucas. After an earthquake in that region earlier this year, hot water was reportedly seen bubbling out of the area. Each winter the climate scientists from around the globe converge on Cabo to study the heat and maybe after decades of study we will learn the cause of the phenomenon.
To which the AGW people will say, see it proves that AGW exists since CO2 a trace gas modulates water vapor…and therefore temperature. Remember, these people already claim via circular reasoning to discount the lack of warming in the SH due to the dominance of ocean area versus land mass.
I notice the steep drop in specific humidity in chart #2.
Why not just point out the fundamental truth here? Warming is not global if 50% of the globe is not warming. If the SH being ocean dominated doesn’t show any signal of warming due to CO2, then CO2 is not a driver of climate change, water vapor is. The heat sink of the atmosphere is water vapor not CO2.
“The mooring was deployed at 47°S, 142°E for March 2010 to March 2011 ”
Am I understanding this correctly? A single location for one year? If so, this says something about the weather over that period of time, not climate.
The missing heat may have been found. The hunt for Trenberth’s brain continues.
Here is a pic of the SOFS mooring being deployed November 2011 from the RV Southern Surveyor
[ http://csirofrvblog.com/author/csirosarahschofield/#jp-carousel-1254 ]
From April 2010
http://www.npr.org/templates/story/story.php?storyId=126312539
Note the NPR objective interviewer invokes climategate emails to let Trenberth off the hook by because his email was “misinterpreted”, and cherry picks only one email. Also note NPR refers to those who disagree with the “consensus” as “climate skeptics”, obviously there are no real scientists outside of the “consensus” and it is only bloggers that deny “science”, so they couldn’t find one single scientist to offer counter points, such as maybe clouds are not well understood and could account for virtually all warming and cooling changes.
And this was the interview that started it all, the ubiquitous “missing heat”.
http://www.npr.org/templates/story/story.php?storyId=88520025
When the first ARGO data were reported, they showed a cooling trend, until the data was adjusted and corrected. Are they still being adjusted as diligently as the surface station data? Are they not warming, despite the adjustments?
I’m sorry, but it’s difficult to trust the data managed by any of these agencies, whose biggest funding dries up when climate change is no longer alarming.
crosspatch says:
August 21, 2012 at 8:49 am
I understood that local observers on a nearby boat saw some pastyfish like thing near where Big Al was snorkelling, they said the bubbles appeared to errupt from the creature’s posterior, & as they bubbled to the surface in abundance, the sound of the words “the Earth has a fever” were heard! So, now we know from which end Al Gore addresses his fan base & the rest of the public at large! Sarc off 🙂
At the risk of spoiling a good joke, surely Trenberth’s missing heat requires a positive heat flux?
Alan the Brit says:
August 21, 2012 at 9:51 am
Those bubbles were caused when Al popped a chakra.
2017 — Thousands of IPCC researchers are shocked to discover the entire global warming signal is caused by the hot air generated at IPCC conferences, and demand funding be tripled in order to investigate this phenomenon.
Ah, ocean heat content. Another of my favourite topics along with cloudiness data, jetstream behaviour and solar variability.
So the southern oceans are losing energy are they ?
Not recharging as they ‘should’.during La Nina events ?
Quelle surprise with higher global albedo resulting from more clouds and meridional / equatorward jets.
All those surges of cold air from the south pole to Australia, South America and South Africa creating more clouds and cutting off insolation.
Meanwhile the Arctic has pretty much lost its ‘hat’ and is pumping the remaining warmth in the north Atlantic out to space at a high rate.
In due course the bleed of energy to space from the Arctic is going to meet the reduced warmth from the southern oceans.
Not many warm seasons left, methinks.
“with extreme turbulent heat loss events, reaching −470 Wm−2 in the daily mean, associated with cold air flowing from higher southern latitudes. ”
Didn’t Marcel Leroux propose just such events sucking energy out from the oceans when his mobile polar highs moved equatorward into the mid latitudes ?
This paper suggests that such events can make the difference between net energy gain and net energy loss.
And such events happen more often and for longer when solar activity is low.
davidmhoffer
You are aware that a good proportion of the historic SST readings from Hadley are taken from a single reading in a year in a grid? These are then extrapolated to adjoiing grids some of which may have no readings at all. Argo seems to be carryng on the tradition.
tonyb
One station/location shows an annual heat loss of -10 W/m², and not the “the Southern Oceans show an annual net heat loss of -10 W/m²”.
I’m reading a book on another topic, Economics (2011), and the authors were reading a book on another topic, Anthropology (1937) and I was so struck by the somethings-never-changeness of their quote. that I’m quoting it: (Just substitute ‘Azande’ with ‘climate experts’)
“In his 1937 account of how the Azande soothsayers dealt with significant events they had failed to predict, Evans-Pritchard might as well have been writing about contemporary commentators of the Crash of 2008 (just substitute ‘ Azande’ with ‘economic experts’):”
“Azande see as well as we that the failure of their oracle to prophesy truly calls for explanation, but so entangled are they in mystical notions that they must make use of them to account for the failure. The contradiction between experience and one mystical notion is explained by reference to other mystical notions.”
(Evans-Pritchard in his Witchcraft, Oracles and Magic among the Azande,1937 , p. 339)
Funny how Warmistas become sticklers for data completeness and geographical coverage at high lats and long term observations when a previous playground for AGW fantasies is probed sharply.
Chilly indeed!
We’ve had temperatures drop below freezing every month this year here in the Copper River Basin.
The Wrangell mountains have not seen snow levels so low in June, July & August since 2002.
Its a tad chilly down south. http://www.wunderground.com/global/AA.html
Wait till next February! The Indian dipole, Antarctic stream, NAO, PDO and AO may provide a great belly laugh for those of us with an open mind, quite soon.
So, we can now rid the planet of the word “Inter-Glacial”, since there can no longer be another glaciation advance? Do tell…
“A paper published August 20th in Geophysical Research Letters finds from newly deployed observation systems that the Southern Oceans show an annual net heat loss of -10 Wm-2.”
No. Wrong.
The paper says there is an average heat loss FROM THE OCEAN TO THE AIR of -10 W/m^2 (for one particular part of the ocean as someone else pointed out recently). In other words, the oceans tend to warm the air in this location (not a big surprise). During the summer (Jan) the air warms the water. In the winter, the water warms the air.
This does not say anything specifically about the net heat loss/gain for the oceans. The ocean could have some OTHER source of heat to balance the air-ocean loss. indeed, the oceans carry considerable energy from the equator toward the poles via the thermohaline circulation.
To claim a net heat loss for the oceans, you would need to compare the air-ocean loss with other gains. If the thermohaline circulation was bringing in 11 W/m^2, then there would be a net GAIN in the ocean even while there was a net loss to the atmosphere.
“That finding contradicts claims that the oceans are gaining ‘missing heat’ due to an increase in greenhouse gases. ”
No. You are comparing apples to oranges. To make this claim, you would want to compare the ocean-air balance now with the values 10 or 100 years ago.
No, no, the missing heat has come over for a holiday around the UK. There was a programme on the august, authoritative BBC (/sarc) only this afternoon about the terrifying effects of a half degree or so temperature rise over the last few decades on the infinitely fragile ecosystems around our coasts. (“Costing the Earth”, part 2, on the iplayer now for those with strong stomachs.) And the BBC wouldn’t lie, would they? (/sarc)
The significance of these measurements at a single location is that heat fluxes over short timescales are orders of magnitude greater than the claimed heat gain from GHG increases.
Any GHG warming is no more than a rounding error.
tonyb says: “You are aware that a good proportion of the historic SST readings from Hadley are taken from a single reading in a year in a grid? These are then extrapolated to adjoiing grids some of which may have no readings at all.”
Please provide a link to the HADSST paper that confirms this.
My last comment seems to have disappeared, so let’s try again. (If is re-appears, then you might get this idea twice …)
No. That is NOT what they found. The found that the net transfer of heat from the ocean to the air is 10 W/m^2. This is the exchange between these two systems, NOT the net transfer to/from the ocean itself.
As an analogy, suppose a doctor pays his lawyer each month for legal services, and the lawyer pays the doctor each month for medical services. At the end of the year, they find that the doctor has paid a net average of $10 per month to the lawyer. This by itself does not tell us whether either of these people individually is getting richer or poorer, because either or both of them could have other income.
For the oceans, one major “other income” is the thermohaline cycle. Considerable energy is deposited into the oceans in some areas (often near the equator), transported around the world, and then released (often near the poles). Depending on the size of this transfer to the specific location of this station, the ocean there could be gaining energy, losing energy, or staying the same.
In truth, the 10 W/m^2 value found here is a SMALL value — rather closer to equilibrium than is found in many areas. Check figure 11.4 at http://paoc.mit.edu/labweb/images/net_heat_flux.htm and you will see that values for this air-sea heat flux can be +/- 100 W/m^2 or more. All this paper is doing is experimentally confirming one point on this map (south of Australia) for one year.
No. That is NOT a logical conclusion. There is no contradiction. Using the analogy above, “gaining heat due to an increase in GHGs” would be akin to “the lawyer starting to pay more to the doctor”. To contradict the “gaining heat due to an increase in GHGs” idea, they would want to collect data (presumably for several years), and look at the trends in the downward heat flux. (And even then we would only have data showing warming, but it would be tough to work backwards simply from that data to assign a CAUSE to the change.)
The original paper is about transfers between ocean and air, about the net effect of global ocean and air currents south of Australia. It is NOT about GHG; not about heat content in the oceans in any specific area. The original paper focuses on the SAME phenomenon that keeps Europe warm (the Gulf Stream) or keeps the west coast of South America cool (the Humboldt Current). If, as Anthony supposes, this finding “contradicts claims that the oceans are gaining ‘missing heat’ due to an increase in greenhouse gases”, then the mere existence of the Gulf Stream ALSO contradicts that claim and in a much more dramatic way.
davidmhoffer said (August 21, 2012 at 9:14 am)
“…Am I understanding this correctly? A single location for one year? If so, this says something about the weather over that period of time, not climate…”
Just as a single tree (remember Yamal?) was the basis for global proxies, right?
Besides, if a single site wasn’t enough, we can always follow the example of Hansen et.al., and simply use this as the center of a 1200km radius circle. The resulting extrapolated area should carry a lot more weight.
Seriously, I’m looking forward to this group taking all available data from the ARGO buoys and running it through their process. Perhaps the owners of the buoys can adapt them to get the type of data they need.
@tjfolkerts
When the oceans release heat, it is not simply an exchange from one system to another because air’s heat capacity is very small. The heat is LOST to space. It doesn’t magically find it’s way back to the ocean.
DR says: August 21, 2012 at 7:51 pm
“When the oceans release heat, it is not simply an exchange from one system to another because air’s heat capacity is very small. The heat is LOST to space. It doesn’t magically find it’s way back to the ocean.”
Heat and energy seem to follow a few basic rules of thermodynamics. There is no thermodynamic rule that says “heat only goes from objects with high heat capacity to objects with low heat capacity”. There is no rule that says “energy that leaves water must go to space”. Now THAT would indeed be magical!
Yes, some energy from the oceans goes straight to space. As does some energy from the land and some energy from the atmosphere. And when energy leaves beyond the atmosphere (as thermal IR or reflected sunlight), it is gone forever. But energy can move from land to atmosphere or from atmosphere to ocean or from ocean to land. It can be transferred by radiation or convection or conduction up and down and sideways. Only magic could overturn thermodynamics and stop energy from moving from the atmosphere to the land and to the oceans.
If you think Jim Hansen’s creations reflect reality more than Jim Henson’s, you might be a green-neck.
“For the oceans, one major “other income” is the thermohaline cycle. Considerable energy is deposited into the oceans in some areas (often near the equator), transported around the world, and then released (often near the poles).”
That process involves sunlight that has penetrated the ocean surface. Nothing to do with air / sea energy transfers.
Energy lost by ocean to air is lost to space.as DR says.
Interesting that the release near the poles is accepted. I’ve had quite some trouble getting AGW theorists to accept that recent arctic ice losses are due to melt from below as a result of decades of warmer oceans caused by a period of active sun.
“During the summer (Jan) the air warms the water. In the winter, the water warms the air.”
Air never warms water due to the huge difference in thermal capacities. Warm air over cooler water becomes colder for virtually zero effect on the water.
In summer (Jan) sunlight warms the water by penetrating the surface.
There is essentially no such thing as air-sea flux. It is all sea-air flux because IR radiation from the air cannot penetrate water, but IR radiation from the sea can penetrate the atmosphere. In engineering terms this amounts to a check valve that allows energy flow in only one direction.
Sure, there is some lunch money conduction going on and whitecap latent heat vaporization (which might turn out to be a real player in the “screaming sixties”).
Everyone likes to think of circumpolar vortices as what river runners know as eddy fences; places wher countervailing flow produces a barrier.The circum-antarctic vortex, which is congruent in the atmosphere and the ocean, is far more than a barrier. The ocean vortex is a thermohaline pump that sucks bottom water from the Atlantic Ocean and injects it into the Pacific and Indian Oceans.
@Bob Tisdale:
Don’t have a “paper”, but it is obvious “by inspection”. GIStemp uses the SST map from Hadley, so I’ll speak to GIStemp… There are 16,000 “grid / boxes” (it was 8,000 then it got doubled) but only 1280 ish thermometers active in GHCN (on land in 2010 IIRC). BY DEFINITION most of those grid / boxes must be empty and devoid of ANY instrument.
http://www.argo.ucsd.edu/
says Argo is up to a bit shy of 3600 buoys now, so it’s getting better. Still, with less than 5000 total of buoys and land, and 16,000 boxes to fill, some have got to be empty and most can have a very low or single instrument.
It is simply unavoidable.
Even with the old 8,000 ‘grid / box’ layout, it was “mostly empty”.
That’s why codes like HadCRUT and GISTemp do the ‘homogenizing’ and ‘infilling’ that they do. If they didn’t, you would see that it’s mostly empty space with no data…
(For those thinking of protesting that GHCN has 6000+ stations: That is ALL stations used at ANY time, including historical ones that are no longer in use. The present measured set is vastly smaller. It was 1280 last time I looked. But then codes like GIStemp throw out some of them, so the working set is even smaller. New stations with less than 20 years data, for example, get ignored.)
@ALL:
BTW, Stephen Wilde has it right, IMHO. Read his stuff. (That we came to very similar ideas from entirely different directions has nothing to do with my opinion 😉 Solar change drives UV levels that drive stratospheric changes that drive the jet streams that changes everything… It’s the atmospheric thickness that’s the key bit we didn’t know about until this sleepy sun cycle hit and we got to see UV fall off a cliff while the air column shortened. Then the jet stream and PDO / AMO / AO / … all swapped …
Watch the Polar Vortex as it dumps incredibly cold air on each pole in the coming years. It’s all about the heat going down the drain in those vortex torrents… Also watch the Southern Current whack into Drake Passage and send an icy shiver up S. America into the central Pacific, then over 18 years it spreads to Alaska and the Arctic Ocean ( we’re already a few years into this process).
CO2 increases heat loss in the air above the stratosphere (where IR leaves) and does nothing lower down (where water dominates heat flow with evaporation / convection / precipitation). The Warmers radiative model is just broken.
Stupid question. Does Argo measure the data required to give a wider picture than this publication (as implied by henrythethird)? My understanding is, it doesn’t.
E.M.Smith said:
“It’s the atmospheric thickness that’s the key bit we didn’t know about until this sleepy sun cycle hit and we got to see UV fall off a cliff while the air column shortened.”
Thanks EMS.
It is slightly more complex than that but you have the right idea.
The issue isn’t so much the atmospheric thickness on its own but rather the gradient of tropopause height between equator and poles.
Change that gradient and the climate zones are able to slide latitudinally with one side effect being a change in the degree of zonality of the jets.
The key to cloudiness changes is the length of the lines of air mass mixing around the globe. Meridional jets add thousands of miles to that length with significant changes in cloud amounts globally.
That is the amplification factor for small UV variations.
Fortunately the system response to a change in the amount of energy entering the oceans is strongly negative with the change in input to the oceans being matched by a change in output to space.
More energy into the oceans when the jets are poleward and zonal also involves a faster energy throughput from surface to space so there is little or no effect on system energy content.
Less energy into the oceans when the jets are equatorward and meridional also involves a slower throughput from surface to space so in the short term there is little or no effect on system energy content.
In each case we just observe regional climate changes as the climate zones and jets reconfigure to match energy in with energy out for the system as a whole.
However, energy denied to the system is energy lost forever and so if the equatorward meridional setup were to last for long enough there would be serious system energy loss. Fortunately the sun doesnt seem to stay in the required state for that long.
Ice ages seem to be attributable to Milankovitch cycles rather than solar UV variability.
So what we have here is an internal system characteristic which gives a significant (from our puny perspective) energy budget response to tiny solar variations by way of the spectral (or particle) mix but the system itself also supplies the necessary damping to maintain system stability long term.
DR on August 21, 2012 at 7:51 pm
@tjfolkerts
When the oceans release heat, it is not simply an exchange from one system to another because air’s heat capacity is very small.
——–
You need to quantify this better.
Sure the heat capacity of air is a whole lot less than that of water.
BUT
Air moves a lot quicker than water. AND the ability of a fluid to transfer heat depends on both speed and heat capacity.
Funny I thought there were some people claiming to be engineers around here. Maybe they nodded off.
gymnosperm on August 21, 2012 at 10:42 pm
There is essentially no such thing as air-sea flux. It is all sea-air flux because IR radiation from the air cannot penetrate water, but IR radiation from the sea can penetrate the atmosphere. In engineering terms this amounts to a check valve that allows energy flow in only one direction.
———
I wouldn’t count on the low penetration depth of IR radiation into the water surface preventing transfer of the energy into the water. The 70
Stephen Wilde says: August 21, 2012 at 9:48 pm
“Air never warms water due to the huge difference in thermal capacities.
NEVER? REALLY? If this were true, you could set a bucket of cold water out in a warm room, and the bucket of water would stay cold!
“Warm air over cooler water becomes colder for virtually zero effect on the water.”
Now we get to the crux. The effect will, in some circumstances, seem like “virtually zero”, but the effect is very real and very important. If you are doing an energy balance, the effect of air on water MUST be included — whether the air is cooling the water or the water is cooling the air.
“If this were true, you could set a bucket of cold water out in a warm room, and the bucket of water would stay cold!”
Energy conducts from the bucket to the water.
Or light energy in the room penetrates the surface
If it were suspended without a container in mid air in a dark room it would indeed stay cold.
Evaporation being a net cooling process there is no energy left over to enter the water. Evaporation is constant for water exposed to air whatever the temperature. If the water is frozen the process is called sublimation.
I find that many have not been taught about the physics of evaporation and condensation in recent decades.
Stephen Wilde says: “If it [some water] were suspended without a container in mid air in a dark room it would indeed stay cold. ”
Evaporation adds an interesting twist, but doesn’t negate conduction. Conduction will always occur from a warmer object (the air in this case) to a colder object (the water in this case) that are in contact. The question then becomes “how do evaporation and conduction compare?”. (For simplicity, we can imagine some sort of insulated thermos container to minimize thermal transfer thru the conatiner, so only the water/air interface matters).
If the humidity is low and the water is cold, then evaporation will remove energy from the water (trying to cool it). Conduction will add energy to the water (trying to warm it). The net effect depends on the actual temperatures and humidity.
On the other hand, if humidity is high, there will be instead condensational warming! If you put out a cold glass of water on a humid summer day, water condenses on the glass. This will WARM the water. (And the same thing is happening at the actual water surface, so the “glass” is not needed to create this warming). In this case, conduction will warm the water AND condensation will warm the water, so it will heat up EVEN FASTER than simply by conduction! .
If humidity is just right, there would be neither evaporation nor condensation, and only the conduction would occur, inevitably warming the water. (If the room is sealed, so the evaporating water cannot escape, then fairly soon the evaporation/condensation process will equilibrate. At this point, conduction between air/water will necessarily bring the water and air to the same temperature.) (IR between walls and water will also be a major player, but this is a separate issue.)
tj,
The subject at issue is an ocean under an open sky with varying wind and humidity and averaged globally evaporation is constantly happening at a high rate.
Furthermore (look it up) the phase change of a water molecule to vapour uses up 5 times as much energy as is required to initiate the process.
That phase change mops up any conducted energy too.
The atmosphere cannot pass energy back to the oceans under the prevailing conditions. You may not like that but it is so.
gymnosperm on August 21, 2012 at 10:42 pm “There is essentially no such thing as air-sea flux.”
You are misunderstanding the way these terms seem to traditionally be used. The “air-sea flux” includes ANY sort of energy crossing the boundary between the oceans and the atmosphere. So even IR from the oceans that passes right on thru the atmosphere would be counted, since it crosses the ocean/atmosphere boundary. http://paoc.mit.edu/labweb/images/net_heat_flux.htm
By looking at the various graphs, we can see
* there is almost no “sensible heat” transferred (ie almost no conduction). There is some heat transferred OUT OF land near the equator, and heat transferred INTO land and water near the poles.
* there is latent heat transfer OUT OF the oceans, strongest near the equator.
* there is net longwave transfer out of the oceans (ie there is more IR leaving the oceans than there is entering the oceans). Interestingly, this is stronger near 30N/30S than near the equator.
The net result is rather complicated. Basically, the net sea-air heat flux is UPWARD where there are warm ocean currents heading pole-ward (eg the Gulf Stream; the tip of South Africa) and the net sea-air heat flux is DOWNWARD where cool currents head toward the equator (eg the Humboldt Current)
“and the net sea-air heat flux is DOWNWARD where cool currents head toward the equator (eg the Humboldt Current)”
Incorrect.
Where cool water flows beneath warmer air it will cool the air but since evaporation is continually occurring the energy from the air that would (without evaporation) have been taken up by the water is lost in the phase change from water to vapour because the phase change absorbs 5 times as much energy as is required to induce it at standard atmospheric pressure.
http://en.wikipedia.org/wiki/Enthalpy_of_vaporization
“the molecules in liquid water are held together by relatively strong hydrogen bonds, and its enthalpy of vaporization, 40.65 kJ/mol, is more than five times the energy required to heat the same quantity of water from 0 °C to 100 °C (cp = 75.3 J K−1 mol−1)”
Not a lot of AGW proponents seem to know that.
TIM: “and the net sea-air heat flux is DOWNWARD where cool currents head toward the equator (eg the Humboldt Current)”
STEPHEN: “Incorrect.”
The data is here http://paoc.mit.edu/labweb/images/net_heat_flux.htm. You can theorize all you want, but that doesn’t change the facts.
You seem to think that the “net sea-air heat flux” must always be from the ocean to the atmosphere, but, based on the standard definition of the term (ie ALL energy passing the boundary between the ocean and the atmosphere), the “net sea-air heat flux” over the globe must average very close to zero — positive in some areas and negative in some areas.
I will grant you, this is certainly not the only way to define “net sea-air heat flux”. For instance, this definition includes solar energy and thermal IR.
But since we are discussing a specific paper using a specific definition and I was using that definition, you really are not free to re-define terms in the middle of the discussion.
“Not a lot of AGW proponents seem to know that.”
I would say that not a lot of people in general know about latent heat. But I would be willing to bet that pretty much all “climate scientists” (with a BS degree or higher) know about the thermal properties of water.
Bob Tisdale
This was from a private email correspondance with a senior scientist following my article
http://judithcurry.com/2011/06/27/unknown-and-uncertain-sea-surface-temperatures/
tonyb
Stephen says: “The subject at issue is an ocean under an open sky with varying wind and humidity and averaged globally evaporation is constantly happening at a high rate.”
There are several issues here.
1) The most direct issue is that the top post misinterprets the paper and draws incorrect conclusions about “net sea-air heat flux”, “missing heat”, and “increase in greenhouse gases”. An accurate understanding of the paper would have eliminated most of the need for discussion.
2) The least important issue is the “containerless water in a dark room” scenario that you invented, and then you misstated that such water could not gain energy from the air in the room. I was addressing that theoretical scenario.
3) The actual ocean is indeed more complex than the scenario we were discussing. I agree that, overall, latent heat flow (evaporation) is far larger than sensible heat flow (conduction). For most of the ocean, the conduction is from the ocean to the atmosphere, but there are specific area near each pole where conduction does, indeed seem to be INTO the ocean. It even appears that in some of these areas (particularly in the Arctic ocean), the conduction into the ocean exceeds the evaporation out of the ocean (which you insist doesn’t happen — “That phase change mops up any conducted energy too”).
“The atmosphere cannot pass energy back to the oceans under the prevailing conditions. You may not like that but it is so.
It appears you are wrong on several counts, as descried above and shown in the linked graphs http://paoc.mit.edu/labweb/images/net_heat_flux.ht.
*The atmosphere CAN AND DOES energy via thermal radiation into the ocean (although the NET radiation seems to always be upward).
* The atmosphere CAN AND DOES (rarely but definitely) pass energy via conduction into the ocean.
* The atmosphere CAN AND DOES (even more rarely) pass MORE energy into the ocean by conduction than the ocean passes into the the air via evaporation.
@Stephen Wilde:
Can’t put a half dozen postings into a single comment, so I “abridged”. Perhaps it was “Abridged too far”? 😉
BTW, On the “does so / does not” on which way heat moves between air and water, my 2 Cents:
It depends on the relative motions.
If the air is moving, everything gets cooler. Existence proofs: A ‘swamp cooler’ or any summer day near the California coast. We get warm air that rises, then a wind starts over the ocean and it evaporates / condenses into fog. Net effect is a cooling fog blanket gets pulled over San Francisco. The ocean does not get warmer. It stays quite cold for a couple of hundred more miles as it flows down to a mixing point with more tropical water headed up from San Diego. Any time you have modestly less than saturated air moving over water, things cool. Heck, dip in the water on a warm day in Florida and step out into a shady spot; you cool. Had an interesting experience once in the Florida / Mississippi Gulf coast. Bottom about 3 feet down was quite warm (solar heated). Surface was cooler (wind). Me, 1/2 out of the water but wet, even cooler from evaporation. It was a very striking demonstration. The solar heated mud was quite warm, the air / water interface cool, the air medium warm. Water in between the mud and surface of in between temperature.
if the air is not moving, and humidity is near 100%, you can get heat flow into the water, but not very much at all. Try a Louisiana Swamp on a 95 – 95 day. ( 95 F and 95 % Humidity). Aint nothing cooling off and it’s all the same temperature… Only deep water can be cooler. Warmth flows into the water during the day, and out at night. But again, not much.
So IMHO “for all practical purposes” it’s going to be an ‘air cools water’ world but with some “nearly null” edge case conditions in shaded bayous…
For the ocean, I’ve never seen a case of zero wind. VERY low, yes, but not zero. Typically it’s a dozen knots+ with waves. So you will get lots of evaporation. In the tropics, it’s tons of water evaporating ( hundreds of inches of rain / year). In the temperate zone less. At the poles you would expect “not much” but the air is so dry it does cause evaporation. Until the water freezes and blocks it. So again, cooling. (Think ‘arctic snow’ … comes from evaporated water). So I can’t think of a single part of the ocean where there are no evaporative conditions. Perhaps when in mid downpour? 😉 Simple fact is that gigatons of water evaporate from the oceans and fall as precipitation, sucking heat up into the sky as hurricanes, typhoons, squalls, thunderstorms, etc. etc. So while there might be some theoretical parcel of air of trivial size that warms a dot of water, the ‘net-net’ is massive surface cooling via evaporation. Evidence? Global precipitation…
http://earthobservatory.nasa.gov/GlobalMaps/
Here you can see precipitation.
http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=TRMM_3B43M
Some areas with very cold water off shore don’t get much rain, but mostly the oceans are rain makers. That ALL comes from evaporation, so cooling. (Even where it isn’t raining, it can still be evaporating for rain making elsewhere.
http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MYDAL2_M_SKY_WV
shows water vapor. Pretty much all over the globe over the oceans. Only goes low over frozen areas and deserts. Water vapor from the ocean via evaporation taking heat with it.
http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MODAL2_M_CLD_FR
Pretty much the whole thing with clouds (on average) made from water evaporated from the oceans (taking heat with them).
So on the global scale, I’m not seeing anywhere for ‘hot air to warm water’… but I’m seeing a whole lot of ‘evaporation transports heat’ (mostly from the places the sun shines the most, the equator / temperate zones to the poles where it gets dumped to space).
Compare this movie of the “net radiation”
http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=CERES_NETFLUX_M
to this one of the sea surface temperature:
http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MYD28M
Looks a whole lot like sunshine warms the ocean that rapidly dumps the heat to the air via evaportaion / rain (as seen in the precipitation movie above) which moves the heat to the top of the thunderheads / cyclones and on to the stratosphere for dumping.
So while I might quibble a bit about “absolutely no heat from air to water under all circumstances” I think it’s pretty clear that any such process is substantially nil in comparison to the rest of the processes. They are clearly “solar heated water evaporates and takes heat to space for dumping, returning as precipitation” and not much else. The moves show that as the various processes move in unison on a gross scale.
“So while I might quibble a bit about “absolutely no heat from air to water under all circumstances” I think it’s pretty clear that any such process is substantially nil in comparison to the rest of the processes”
Agreed.
Tim is trying to salvage his position by emphasising the theoretical likelihood of a process that isn’t much different to zero.
@Stephen Wilde: Yes….in the good old days every child knew that when it rains raindrops lose its heat.
Tim Folkerts says:
August 22, 2012 at 3:11 pm
TIM: “and the net sea-air heat flux is DOWNWARD where cool currents head toward the equator (eg the Humboldt Current)”
STEPHEN: “Incorrect.”
The data is here http://paoc.mit.edu/labweb/images/net_heat_flux.htm. You can theorize all you want, but that doesn’t change the facts.
————————————————-
Have you looked at the data you post?
Positive into the oceans, negative outside – see 11.4 below at solar and longwave in your post.
If you go to longwave it is only outside, no “in”
The reason is simple: the surface of the oceans forms a temperature gradient that is well know, where the surface is cooler then the few centimeters below. In such case there is no heat transfer from upper level to lower level through conduction or convection.
See cool skin simulation:
researcher.nsc.gov.tw/public/tsuang/Data/722815193371.pdf
“It is well known that temperatures at the sea surface are typically a few-tenths degrees Celsius cooler than the temperatures some tens of centimeters below [Saunders, 1967; Paulson and Simpson, 1981; Wu, 1985; Fairall et al., 1996; Wick et al., 1996; Donlon et al., 2002].
There is no observed inversion of the skin gradient, so the only part of the ocean that could be warmed by longwave is the surface.
The temperature of the surface can be and is well observed.
The depth can be warmed only by shortwave. Solar penetration:
http://lasp.colorado.edu/sorce/images/instruments/sim/fig01.gif
Lars says: “Positive into the oceans, negative outside”
The graph says: ” (positive is out of the ocean, negative in to the ocean)”
Your statement is exactly opposite what the link says. I don’t think I am the one who needs to look at the data again.
“If you go to longwave it is only outside, no “in” “
I think you are misinterpretting something here.
1) The flux is not “inside” or “outside” by “inward” and “outward”.
2) There is both a positive outward longwave flux (ie the ~ blackbody radiation from the ocean surface upward) and inward negative flux (the highly non-blackbody radiation from the GHGs and clouds down to the surface). If you meant the NET longwave flux was always OUTWARD, then I agree.
(Much of the rest of what you say I agree with, like the existence of a cool skin layer of the ocean and only shortwave EM energy being able to penetrate beyond a thin layer at the top.)
DR says: @ August 21, 2012 at 7:51 pm
“When the oceans release heat, it is not simply an exchange from one system to another because air’s heat capacity is very small. The heat is LOST to space. It doesn’t magically find it’s way back to the ocean.”
__________________________
Tim Folkerts says:
August 21, 2012 at 9:04 pm
Heat and energy seem to follow a few basic rules of thermodynamics. There is no thermodynamic rule that says “heat only goes from objects with high heat capacity to objects with low heat capacity”. There is no rule that says “energy that leaves water must go to space”. Now THAT would indeed be magical!
_________________________________
There may no be a rule in thermodynamics but there is the fact that the ocean gets its heat from the sun and not the air. That is based on the absorption spectra.
Graph of the energy of incoming vs outgoing energy by wavelength: link
The wavelength from 10 to 20um (where the majority of the energy from the earth is radiated) passes through the atmosphere esp. if the amount of H2O vapor is small. Graph
Therefore the air does toss energy to space.
However the ocean absorbs its energy from the HIGH END of the solar spectrum and not the air.
graph
The wavelenghts vs depth graph
The longer the wavelength the less energy BTW so IR has very low energy at each specific wavelength emitted by the earth’s surface/air. chart and explanation
The air itself might “warm” the ocean but it is by a very negligible amount. It’s the Sun what done it gov.
Stephen says: “Tim is trying to salvage his position by emphasising the theoretical likelihood of a process that isn’t much different to zero.”
No, I am trying to prevent the propagation of a few specific errors. For instance, when you categorically say I am “incorrect” when in fact I am correct (based on standard definitions of “net air-sea heat flux”). OR when you conclude ”
In truth, we are not that far apart in our positions. I suspect we agree that (for an annual average over the earth)
* Sunlight is the biggest form of energy flux into the oceans
* Evaporation is the biggest form of energy flux out of the oceans
* Conduction is a much smaller form of energy flux out of the oceans (maybe 1/5 or 1/8 as much as evaporation).
* Thermal IR (composed of a large upward flux and a smaller downward flux) is a net energy flux out of the oceans.
From what I recall from other previous discussions, our main disagreement deals with the effect of increased GHGs. I think that more GHGs will produce mroe downward IR, which will increase the evaporation rate by increasing the surface temperature of the ocean slightly. I believe you feel the evaporation rate will go up with on increase in surface temperature (but I could be wrong).
Gail,
I agree with many of the facts and graphs you presented. Let me make a couple quick points.
“The wavelength from 10 to 20um (where the majority of the energy from the earth is radiated) passes through the atmosphere esp. if the amount of H2O vapor is small.”
1) even if the “majority” passes through, there is still some IR that gets absorbed. The air in turn can radiate IR in various directions including downward.
2) Clouds are nearly perfect blackbodies. Thermal IR energy from the surface gets blocked almost 100% by the clouds. The clouds in turn radiate very efficiently back to the surface.
All together, the downward IR flux from GHGs and clouds is certainly less than the upward energy, but the downward energy is a large fraction of the upward thermal IR from the surface. The air returns some of the energy back to the surface — no magic needed.
“Therefore the air does toss energy to space.”
Yes, but it also “tosses: energy back to the surface.
“However the ocean absorbs its energy from the HIGH END of the solar spectrum and not the air.”
I’m not sure what your point is. The SURFACE of the ocean absorbs energy from IR from GHGs & clouds. The DEEPER layers of the ocean absorb energy from the “HIGH END of the solar spectrum” The entire spectrum eventually gets absorbed by the ocean. The entire spectrum contributes to the heating of the ocean.
“The air itself might “warm” the ocean but it is by a very negligible amount.”
I guess that depends on your definition of “negligible”. Everything else being equal, the atmosphere (including water vapor & clouds) returns enough energy to warm the earth several degrees (33 C by some estimates) — I would hardly call that “negligible”.
Tim Folkerts says:
August 23, 2012 at 9:20 am
Lars says: “Positive into the oceans, negative outside”
The graph says: ” (positive is out of the ocean, negative in to the ocean)”
….. If you meant the NET longwave flux was always OUTWARD, then I agree.
(Much of the rest of what you say I agree with, like the existence of a cool skin layer of the ocean and only shortwave EM energy being able to penetrate beyond a thin layer at the top.)
——————————————————————————–
Tim yes, I expressed myself badly wrong in the line, however good that you got the meaning.
We both agree that heat transfer cannot happen from the surface of the ocean to the deeper layers as long as there is a cool skin, which means that any warming coming from greenhouse stops at the skin layer.
If the skin layer is getting warmer in average only then we can start talking about possible influence of the GHG everything else staying the same.
I would say that this could make an interesting lab experiment, however have not seen such.
The conclusion from what we say above is that it is wrong to try to make any direct connection between greenhouse gas energy and ocean heat content in terms of energy transfer.
The exchange between atmosphere and ocean happens only at the skin layer.
If there are any changes in the skin layer temperature, then, only then, eventually the ocean may retain more heat from the sun.
The global sea surface temperature are known and measured:
http://bobtisdale.wordpress.com/2012/08/06/july-2012-sea-surface-temperature-sst-anomaly-update/
The variations show very little warming which may be attributed to other factors like less clouds or small increase in solar radiation (if we compute ACRIM composite and not PMOS) and would point to a very small climate sensitivity to CO2.
This keeping in mind that all the heat from CO2 and all GHG are blocked at the skin layer, and not going down in the ocean.
Lars.
Thanks for your contribution.
I have previously tried to tell them over at a warmist site that only if the temperature gradient through the cool skin layer declines could there be any effect on the ocean bulk from downward IR.
There has been no evidence produced to that effect.
Since that cooler skin layer is caused by evaporation plus radiation removing energy faster than it can be brought up from below it follows that more evaporation would intensify that cool layer and not dissipate it.
Thus the extra downward IR from more CO2 (if any) cannot warm the ocean bulk.
[snip – embedded advertising link in an otherwise relevant comment ]
[snip – embedded advertising link in an otherwise relevant comment ]
“Thus the extra downward IR from more CO2 (if any) cannot warm the ocean bulk.”
You seem to be saying that extra 10 W/m^2 of extra IR will lead ONLY to increased evaporation, but not to ANY warming of the surface of the ocean. Am I right?
By that logic, you would say that a decrease of -10 W/m^2 should not lead to cooling, but only to decreased evaporation. Am I right?
But what if we decrease the downward IR by -80 W/m^2. Your logic would say there is STILL no cooling, but evaporation would have to stop (since there is only ~ 80 W/m^2 of evaporation from the oceans). So we would have water at the SAME temperature as now, with NO evaporation!
No, what would happen instead if we cut the incoming IR by 80 W/m^2 is that evaporation would decrease somewhat (perhaps by 60 W/m^2) and the outgoing IR would also decrease (say by 20 W/m^2) so that the total change would equal the change in the incoming IR. But to decrease the outgoing IR, the surface temperature would have to drop.
So I agree that MUCH of the increased IR would simply go into speeding up the water cycle, but SOME of it must go into warming the surface of the oceans.
Evaporation cannot stop under an open sky with air movement because that movement keeps humidity below 100%.
There is a basic minimum rate of evaporation which is independent of downward IR.That is set by solar input plus pressure at the surface.
ALL downward IR onto a water surface adds to evaporation provided humidity is less than 100% and ALL is used up by the phase change.Taking the Earth as a whole humidity is on average always way below 100%.
If any area gets closer to 100% then windiness increases and more vapour is whisked upward or laterally.
Here is an example as to how the numbers work:
i) The basic rate of evaporation removes, say, 10 units of energy from the water every minute.
ii) Meanwhile, at some precise moment, 5 units of IR hit the surface.
iii) 1 unit has enough time to provoke extra evaporation but then, instantly, because the enthalpy of vapourisation is 5 to 1, the phase change soaks up the rest of the 5 units of downward IR with no effect on the basic rate of 10 units of energy removed from the water per minute.
iv) There doesn’t even need to be a surface temperature change because all of those 5 units go straight to latent heat which does not register on thermometers.
vi) The gradient of temperature within the cooler ocean skin changes not at all and the bulk ocean temperature is unchanged.
Tim Folkerts:”So I agree that MUCH of the increased IR would simply go into speeding up the water cycle, but SOME of it must go into warming the surface of the oceans.”
I have a hard time understanding the logic here. If the surface of the ocean is cooler than both the sub-surface water and the air above it, doesn’t this imply that there can be no net transfer of heat into the surface water. Is your point simply that the surface cools less when the air above it is warmer?
Cheers, 🙂
“ALL downward IR onto a water surface adds to evaporation … There doesn’t even need to be a surface temperature change …
But you still miss the logic fallacy of your argument. If ANY increase in IR ONLY increases evaporation with no surface temperature increase, then ANY decrease in IR ONLY decreases evaporation, with no decrease in temperature. But downward IR is WAY more (~ 300 W/m^2) than evaporation (~ 100 W/m^2). So if IR decreases by 100 W/m^2, then, by your logic, we would stop evaporation without any other change in surface temperature!
Shawnhet asks: “I have a hard time understanding the logic here. If the surface of the ocean is cooler than both the sub-surface water and the air above it, doesn’t this imply that there can be no net transfer of heat into the surface water. Is your point simply that the surface cools less when the air above it is warmer?”
A good question! The answer requires understanding the total balance of heat. Let’s think about the surface skin layer and the subsurface bulk oceans as two different systems.
1) There IS a transfer of energy into the subsurface from sunlight.
2) There is no transfer out of the subsurface by evaporation or thermal IR (both are blocked by the skin layer).
3) The method of cooling the subsurface to maintain an approximate equilibrium must then be by conduction thru the skin layer.
4) To conduct thermal energy thru the skin layer, the top of the skin layer must be cooler than the bottom of the skin layer (as is indeed observed) (the top of the skin layer is cooled by conduction to the air, thermal IR and evaporation)..
5) Conduction depends on the temperature gradient. If the top of the skin layer is heated (say by an electric heater or IR light), then the gradient decreases, and the conduction upward thru the skin layer decrease.
6) If the downward sunlight stays the same, but the upward conduction decreases, then there must be a NET transfer into the oceans.
Of course, this all assumes that thermal IR actually can warm (or cool) the surface. If Stephen Wilde is correct that evaporation rates can be increased without changing the wind, surface pressure, humidity or surface temperature, then (5) would be wrong and the argument would fall apart.
“But downward IR is WAY more (~ 300 W/m^2) than evaporation (~ 100 W/m^2). So if IR decreases by 100 W/m^2, then, by your logic, we would stop evaporation without any other change in surface temperature!”
I don’t accept the standard AGW view of downward IR. I think it is just the temperature of the air molecules just above the surface.The warmer they are the more evaporation there will be and at standard atmospheric pressure plus current levels of insolation the temperature of the air molecules above the surface is equivalent to what would be produced if there were a radiator in the sky giving off 300 W/m2
At standard atmospheric pressure and current levels of insolation that air temperature at the surface happens to produce a background rate of evaporation with the energy value of 100 W/m2.
Assuming those suspiciously round numbers are accurate.
So if the molecules near the surface do become a bit warmer, say rising to the equivalent energy value of a radiator in the sky producing 305 W/m2 then 1 of the extra units will provoke more evaporation and the other 4 will be instantly mopped up too.
The background evaporative flow from the water to the air will still be at 100 W/m2 so the warmer air has failed to warm the ocean bulk at all.
This is where we get into the contentious issue of atmospheric pressure but that is for another day.
I could never reach agreement on this issue with someone who thinks there actually is a radiator floating about somewhere in the sky.
“If Stephen Wilde is correct that evaporation rates can be increased without changing the wind, surface pressure, humidity or surface temperature”
Not what I said. Changes in windspeed, surface pressure and humidity do change (indeed the entire global air circulation changes albeit imperceptibly from human emissions) so as to facilitate a fast enough evaporative response to either prevent a surface temperature increase altogether or eliminate it over time averaged around the planet.
We have to be careful about the term surface temperature because I concede that it will change locally or regionally when the air circulation reconfigures in order to maintain balance between solar energy in and longwave out. I prefer to say that the system energy content remains much the same over time.
“This is where we get into the contentious issue of atmospheric pressure but that is for another day.”
It may help if I make a brief comment.
Atmospheric pressure at the ocean surface sets the energy value of the enthalpy of vapourisation. At 1 standard atmosphere the ratio is 5 to 1.
That gives us the energy cost of a given amount of evaporation so unless one changes atmospheric pressure that energy cost per unit of evaporation stays the same.
The fact is that at 1 standard atmosphere at current levels of insolation and the current landmass distribution the energy cost of a given amount of evaporation from the oceans requires an air temperature above the surface equivalent to a radiator in the sky producing 300 W/m2 to produce 100 W/m2 of evaporation.
You can increase or decrease the temperature of the air or of the oceans by whatever means you like but if the water surface remains exposed to the open sky then the energy cost of a given amount of evaporation stays the same if atmospheric pressure remainds at 1 standard atmosphere.
If the air is warmer than the water then the warmer air causes more evaporation but because the air is warmer the evaporative process takes the extra energy from the warmer air until it comes down to the water temperature.
If the air is colder than the water then less evaporation occurs but when it does occur the evaporative process takes the extra energy it needs from the water until it comes down to the air temperature.
So the evaporative process, taking the energy it needs from whichever medium air or water is best able to supply it, imposes an automatic negative system response to warming or cooling of either air or water.
Anything that warms the air causes a faster loss of energy from the air to reduce the warming of the air.
Anything that cools the air causes a faster loss of energy from the water to the air to reduce the cooling of the air.
Anything that warms the oceans causes a faster loss of energy to the air to reduce the warming of the oceans.
Anything that cools the oceans causes a slower loss of energy from oceans to air to reduce the cooling of the oceans.
In practice these changes translate into global air circulation changes until solar energy once more matches longwave energy out.
That is how climate variations occur and the atmospheric response involves changes in the vertical temperature profile of the atmosphere and the latitudinal positioning of the jets and climate zones.
One of the phenomena that the system never produces is warmer air producing more evaporation but the evaporative process taking the extra energy it needs from the water before the air has come down to the temperature of the water.
AGW theory relies on the happening of that impossibility because unless CO2 warms the oceans first it cannot warm the air.
In fact it just warms the air and the sea / air interaction then causes an air circulation response that ejects the additional energy to space sooner thus cancelling the warming effect of the CO2.
Slight correction:
Anything that warms the air above the water temperature causes a faster loss of energy from the air to reduce the warming of the air.
Anything that cools the air below the water temperature causes a faster loss of energy from the water to the air to reduce the cooling of the air.
Anything that warms the oceans above the air temperature causes a faster loss of energy to the air to reduce the warming of the oceans.
Anything that cools the oceans below the air temperature causes a slower loss of energy from oceans to air to reduce the cooling of the oceans.
Another correction (doing this too late at night):
“One of the phenomena that the system never produces is warmer air producing more evaporation but the evaporative process taking the extra energy it needs from the water before the air has come down to the temperature of the water.”
should be:
“One of the phenomena that the system never produces is warmer air producing more evaporation but the evaporative process taking insufficient energy for its needs so that there is a surplus left over to warm the water.”
“I don’t accept the standard AGW view of downward IR. I think …
I could never reach agreement on this issue with someone who thinks there actually is a radiator floating about somewhere in the sky.”
Then there is no point in continuing this discussion. You “don’t accept” standard physics, replacing it with your own musings. It is easy to measure downward IR radiating. It is easy to match this downward IR to GHGs and clouds. But you simply choose not to accept this. Instead you hypothesize some vague ‘equivalent of a 300 W/m^2 radiator that is not a radiator’. You actually seem to have a good understanding of much of the science and make some good arguments. But then you seem to choose not to accept specific parts that conflict with your desired conclusion.
If you are comfortable creating your own science — cool — just don’t expect to convince others.
Tim Folkerts:”6) If the downward sunlight stays the same, but the upward conduction decreases, then there must be a NET transfer into the oceans.”
I am not sure that this follows necessarily, unless you ignore the effects of evaporation. Evaporative cooling will recreate a gradient and reduce or eliminate the transfer into the ocean. By my calculations, raising the temp of 1 kg of water at the surface by 1C will require ~4.2 KJ but by Clausius and Clapeyron increasing the temp of the water by that amount will increase evaporation by 6% which will require .06 kg of water to be evaporated which will take ~135KJ. IOW, ~3% of the total flux would go into the ocean, and 97% would go to driving the water cycle faster.
Now, this is overly simplistic I am sure as warming the very top of the ocean will most likely have effects on subsurface (of the ocean) temps. But doesn’t this highlight the fact that you need to include some ideas about how the temperature of the ocean as a whole will behave when exposed to a warmer atmosphere.
Cheers, 🙂
I’ll try one more time to try and explain my point; It is not easy because as far as I know this is a new way of lookng at the issues but I think a more accurate way.
At current atmospheric pressure and level of insolation the system requires certain consequences to enable thermal energy in to match thermal energy out, namely:
i) An average flow of energy from the oceans at the rate of 100 W/m2 PLUS
ii) A temperature of the air at the surface equivalent to the air temperature that would be achieved if there were a radiator in the sky producing 300 W/m2 (the cause is not an actual radiator but the combined effect of pressure and insolation on the temperature of the air molecues at the srface) PLUS
iii) An air circulation configured as it is today so as to ensure that the sea / air energy exchange is just right to support the energy in from the sun / energy out to space balance for the system a a whole.
All three are required to be in balance to achieve the current global system energy content (not temperature because that varies regionally and locally a great deal and does so in 3 dimensions from the bottom of the oceans to the top of the atmosphere)..
The first two are dictated by surface pressure and solar input acting together on the different physical properties of air and water. It is those different physical properties which cause the different thermal responses in air and water to the same pressure and insolation.
The third is controlled by humidity, windiness and slight surface pressure variations around the globe which give rise to adjustments in the rate of evaporation from the oceans. Those slight pressure variatons result in climate zones and jet streams which then serve as the means by which humidity and windiness can vary so as to induce changes in the rate of evaporation.
The slight surface pressure variations are caused in the first instance by the fact that water vapour is lighter than air and so produces convection without any necessary change in temperature.
So, if anything seeks to alter the net rate of energy flow from ocean to air without a change in average global surface pressure or insolation then that will disrupt the system balance such that the energy in from the sun will no longer be matched by energy out to space.
The consequence will be a change in circulation involving humidity and windiness and shifts of the surface pressure distribution in the form of climate zones and jetstreams.If energy out exceeds energy in for any reason the atmosphere shrinks and vice versa. The expansion or shrinkage affects the circulation patterns.
That change in circulation restores the energy in energy out balance and in the process eliminates the thermal effect of whatever force was trying to alter the rate of energy flow from oceans to air.As explained before, the changes in the rate of evaporation will extract the extra energy needed from whiche medium is warmer than it needs to be to support the energy in / energy out balance for the system as a whole.
If the water gets a little too warm so that the upward energy flow exceeds 100 W/m2 then the faster evaporation takes the excess from the water and flings it upward to space faster leaving the energy content of the bulk ocean uchanged.
If the air gets a little too warm so that the energy in the surface air molecules exceeds that 300 W/m2 then the faster evaporation takes the excess from the air and flings it up to space faster without any change in the energy content of the bulk ocean.
Thus is the air circulation as a whole the global thermostat (not just the tropics as per Willis Eschenbach).
Nothing other than changes in surface pressure or insolation will alter the system energy content though there will be changes in surface temperatures whilst the adjustments to the speed of energy flows through the system change in response to nfluences other than changes in pressure or insolation.
The point for AGW theory being that, yes, more human emissions of CO2 would have an effect but the natural effects (from other causes such as global cloudiness and albedo changes caused by top down solar variations and variations in the rate at which the oceans release energy to the air caused by internal ocean cycling) are hugely greater..
In face of those natural forcings our changes in CO2 count for nothing at all in terms of changes in atmospheric circulation.
And in the end the changes of air circulation always succeed in maintaining system stabilty by matching the sea / air energy exchange to support overall system balance where energy in equals energy out.
Otherwise we could not have had liquid oceans for 4 billion years despite huge asteroid impacts and widespread volcanic outbreaks.
Tim Folkerts says:
August 24, 2012 at 12:07 pm
“ALL downward IR onto a water surface adds to evaporation … There doesn’t even need to be a surface temperature change …
But you still miss the logic fallacy of your argument. If ANY increase in IR ONLY increases evaporation with no surface temperature increase, then ANY decrease in IR ONLY decreases evaporation, with no decrease in temperature. But downward IR is WAY more (~ 300 W/m^2) than evaporation (~ 100 W/m^2). So if IR decreases by 100 W/m^2, then, by your logic, we would stop evaporation without any other change in surface temperature!
——————————————
Tim, I have a couple of thoughts experiments for you, can you give me your understanding on these 2 examples?
1) Considering the case downwards IR would not exist (on the moon for instance), we place a rock under the sun at 0°C temperature, wrapped in a surviving foil not to lose heat, would the rock get warmer or not?
To make the case more difficult we place a filter and there is only about 100 W/m2 sun radiation hitting the rock, will it warm up or cool down?
http://en.wikipedia.org/wiki/Space_blanket
2) Considering the case it is night and there is no sun radiation we place the rock still at 0°C on the ground – this time on the earth with average air temperature at the ground at 0°C – wrapped in the same surviving foil, would it get warmed up by the 300W/m2 from the -X°C air above?
Lars proposes a couple thought experiments …
I don’t think your thought experiments are well-posed enough to really give an answer yet.
* Is there any thermal conduction to/from the surrounding air/ground? (Conduction will be important in most real-life situations.)
* is there any IR from the ground? (A rock above the ground would also get “up-radiation” from the ground below/beside unless we block that as well).
* what are the properties of the space blanket? If you have and idealized space blanket that PERFECTLY reflects all photons, then neither external sunlight nor external IR sources would make any difference — only conduction and the initial temperature of the rock would matter. If it only reflects “very well” then it will matter how well it reflects sunlight and how well it reflect thermal IR.
I think the “space blanket” is an unnecessary complication. I think you could pose your scenarios more easily with some other mechanism to focus on the specific issues you want to address.
tjfolkerts says:
August 25, 2012 at 11:57 am
Lars proposes a couple thought experiments …
Tim… Why would you try to avoid the question and focus on small details?
The question to be answered is simple:
Can 300 W/m2 radiation from colder atmosphere be compared with 100 W/m2 radiation from the sun? Are these same kind? Yes or No?
If there is any difference and what is the difference?
I do not propose the exercise to disprove “back radiation” or to say that it has zero influence, but to put it in its right place. 300 Watt from colder object A towards a warmer object B does not increase the temperature of that object B at all. It is no net heat transfer as you seem to consider it.
To my understanding through averaging back radiation and taking it away from the heat transfer process where it occurs we tend to forget what it is. Your sentence : But downward IR is WAY more (~ 300 W/m^2) than evaporation (~ 100 W/m^2)
is in this view very wrong
I don’t think your thought experiments are well-posed enough to really give an answer yet.
* Is there any thermal conduction to/from the surrounding air/ground? (Conduction will be important in most real-life situations.)
No. better consider the surrounding air/ground at 0°C as the rock and as isolated as possible from these
* is there any IR from the ground? (A rock above the ground would also get “up-radiation” from the ground below/beside unless we block that as well).
see above
In my view the exercise is simple, one can take his own rock, measure its temperature and put it in the garden in the night. observing its temperature. One can also point the instrument to the sky and measure downwelling IR. Isolate the rock as much as possible from other temperature exchange, we want to focus now on this source and its influence.
Don’t make the matter more complex, consider the ground at 0°C everywhere or at “rock temperature”.
Make your own assumptions if you don’t like the space blanket.
Then take a different heat source with a very high temperature. A radiator could be also ok – important is to meet the Watts/m2 you measure from downwelling radiation. See what happens. Keep the rock isolated from other heat exchange as much as possible.
* what are the properties of the space blanket? If you have and idealized space blanket that PERFECTLY reflects all photons, then neither external sunlight nor external IR sources would make any difference — only conduction and the initial temperature of the rock would matter. If it only reflects “very well” then it will matter how well it reflects sunlight and how well it reflect thermal IR.
I think the “space blanket” is an unnecessary complication. I think you could pose your scenarios more easily with some other mechanism to focus on the specific issues you want to address.
the space blanket is to isolate on the silver side, so yes silver side on the rock to let it lose as few heat as possible. I understand a space blanket lets lose about 3% and isolates 97% from the silver side.
The idea is to keep the rock isolated as much as possible from heat exchange with any other object in the environment except the energy sources we want to understand:
-1) IR radiation from a colder object
-2) shortwave radiation – or if you prefer IR radiadiation from a warmer object with significant temperature difference, but keep same Watts/m2 or even less
Lars asks :”Tim… Why would you try to avoid the question and focus on small details?
The question to be answered is simple.”
Because all those “small details” will affect the answer to your thought experiment! You are asking about radiation balance, but then you include the space blanket, one of whose main purposes is to block the selfsame radiation!
I’ll work with the principle here:
So in broad strokes …
1A) If we consider “typical surface conditions” with sunshine but no “back-radiation” the sun would provide ~ 160 W/m^2 (averaged over 24 hours). The rock (assumed to have emissivity =1) would have an effective surface temperature of 231 K = (-42 C) (averaged over 24 hours). (Actually, because of the T^4 power-temperature relationship, the average would be lower, but we will ignore those details too). Of course, it would be warmer during the day and cooler at night.
1B) If we consider “blackbody surface conditions” (no sunshine absorbed/reflected by the air; no sunshine reflected by the rock) with sunshine but no “backradiation” the sun would provide ~ 340 W/m^2 (averaged over 24 hours). The rock would have a surface temperature 278 K. (around +5)
1C) By adjusting the albedo and/or absorption by the air, the temperature could be anywhere from -42C to +5C
1D) By decreasing the emissivity, the temperature of the rock would go up from the above numbers.
2A) If we consider “Typical back-radiation” of 333 W/m^2, the rock would have a temperature of about 277 K (~ 4 C) if back-radiation was the only heat source.
2B) On a cloudless night, the back-radiation would be less. Using the calculations from MODTRAN for a cloudless night with “Standard US Atmosphere” the back-radiation would be ~ 259 W/m^2 or 260 K = -13 C
2C) on a cloudy night, the back-radiation would be enhanced. Again using “Standard US Atmosphere” and adding low stratus clouds, the back-radiation would be ~ 362 W/m^2 or 283 K = +10 C.
Obviously by playing with atmospheric condition, we can get a wide variety of answers for the temperature of the rock. None of these numbers is hard to find; none of the calculations are difficult. I would encourage you to do them yourself.