Guest Post by Willis Eschenbach
I’ve been investigating one of my favorite datasets in the last few days, the CERES satellite-based top-of-atmosphere (TOA) radiation dataset. In particular, I’ve taken month-by-month global and hemispheric averages of the data. The dataset consists of observations of three variables—downwelling solar radiation, upwelling longwave (infrared) radiation, and upwelling shortwave radiation (reflected sunlight). From these I derive a further dataset. This is the top-of-atmosphere (TOA) imbalance. It is calculated as downwelling solar minus upwelling (reflected) solar minus upwelling longwave. That gives a fascinating look at the overall radiation picture.
I got to thinking about this because of a curious claim in a recent paper published in Nature Climate Change entitled Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods (paywalled). I did love the whole concept of “model-based evidence”, but that wasn’t what caught my eye. It was this statement (emphasis mine):
There have been decades, such as 2000–2009, when the observed globally averaged surface-temperature time series shows little increase or even a slightly negative trend (a hiatus period). However, the observed energy imbalance at the top-of-atmosphere for this recent decade indicates that a net energy flux into the climate system of about 1 W m−2 (refs 2, 3) should be producing warming somewhere in the system (refs 4, 5). Here we analyse twenty-first-century climate-model simulations that maintain a consistent radiative imbalance at the top-of-atmosphere of about 1 W m−2 as observed for the past decade. [References are listed at the bottom of this post.]
Anyhow, here’s some news regarding that claim of a consistent TOA imbalance, from the CERES satellite dataset:
Figure 1. CERES satellite-measured top-of-atmosphere (TOA) radiation levels, starting in January 2001. Numbers on the horizontal axis are months. Shown are the solar energy entering the system (red line), solar energy leaving the system (dark blue line) and longwave (infrared) energy leaving the system (light blue line). The overall monthly imbalance at the TOA is shown at the bottom in purple. The 12-month running average for each variable is shown as a thin line. Curiously, the variations in upwelling longwave are about 6 months out of phase with the downwelling radiation. All radiation values are positive. TOA Imbalance is solar less reflected solar less outgoing longwave, i.e. inflow less outflow. Twelve-month averages vary too little for the changes to be visible at this scale.
Now, there are a number of things of interest in this chart. The first is the fact that while the seasonal variations are fairly large, tens of watts per square metre, the annual variations are so small. At this scale we can hardly see them. So let’s expand the scale, and take a more close-up look at just the variations in the overall TOA energy imbalance (purple line at bottom of Figure 1). Figure 2 shows that result.
Figure 2. Closeup of the overall energy imbalance. Horizontal scale is months. Narrow line shows running centered 12-month averages of the TOA imbalance data. All radiation values are positive. TOA Imbalance is solar less reflected solar less outgoing longwave, i.e. inflow less outflow.
Here, we can begin to see the small variations in the 12-month running average. However, the average itself is around five watts per square metre … not good. That much out of balance is not credible.
This shows the difference between precision and accuracy. You see that the measurements are obviously quite precise—the 12-month running average only varies by about three-quarters of a degree over the whole period.
However, in absolute terms they’re not that accurate, we know that because they don’t balance … and it’s very doubtful that the earth is out of balance by five watts per square metre. That’s a very large amount, it would be noticed.
Now, I’ve previously discussed how James Hansen deals with this problem. He says:
The precision achieved by the most advanced generation of radiation budget satellites is indicated by the planetary energy imbalance measured by the ongoing CERES (Clouds and the Earth’s Radiant Energy System) instrument (Loeb et al., 2009), which finds a measured 5-year-mean imbalance of 6.5 W/m2 (Loeb et al., 2009). Because this result is implausible, instrumentation calibration factors were introduced to reduce the imbalance to the imbalance suggested by climate models, 0.85 W/m2 (Loeb et al., 2009).
As a result, Hansen used the Levitus data rather than the CERES data to support the claims of a ~ one watt per square metre radiation imbalance. However, all is not lost. The precision of the CERES data very good. In Figure 2 we can see, for example, how one year’s TOA radiation imbalance is different from another. So let’s expand the scale once again, and take an even closer look at just the 12-month running averages, for all four of the radiation measurements shown in Figure 1.
Figure 3. An even closer look, this time at just the tiny variations in the 12-month running averages of the CERES data as shown in Figure 1. All radiation values are positive. TOA Imbalance is solar less reflected solar less outgoing longwave.
Now we’re getting somewhere.
The first thing I noticed is the precision of the measurements of the downwelling solar radiation (red line). As you might expect, the sun is quite stable, it doesn’t vary much compared to the variations in reflected solar and upwelling longwave radiation. And the observations reflect that faithfully. So it seems clear that their instruments for measuring radiation are quite precise.
Next, I noticed that the change in the imbalance (purple) is more related to the change in reflected solar (dark blue) than to the variations in upwelling longwave. I’ve highlighted the reflected solar (dark blue) in the graph above. This is confirmed by the correlation. The R^2 between TOA imbalance and reflected solar is 0.67; but between TOA imbalance and upwelling longwave, R^2 is only 0.07.
This seems like an important finding, that the imbalance is mostly albedo related, and that because of variation in the albedo, the variations in the reflected solar energy were on the order of ± three tenths of a watt within a few years.
Finally, I am once again surprised by the overall stability of the system. Twelve-month averages of all three of the variables (the TOA balance, reflected solar, and upwelling longwave) are all stable to within about ± 0.3 watts per square metre. Out of a total of 340 watts per square metre going each way, that’s plus or minus a tenth of one percent … I call that extremely stable. Yes, with a longer sample size we’d likely see greater swings, but still, that’s very stable.
And that brings me back to the quotation from the paper where I started this post. They say that there is
… a consistent radiative imbalance at the top-of-atmosphere of about 1 W m−2 as observed for the past decade …
Now, according to their references [2] and [3], this claim is based on the idea that the excess energy is being soaked up by the ocean. And this claim has been repeated widely. I’ve discussed these claims here. The claims are all based on the Levitus ocean temperature data, which shows increasing heat in the ocean. Here’s my graph of the annual forcing needed to give the changes shown by Levitus in ocean heat content:
Figure 4. Annual forcing in watts per square metre needed to account for the energy going into or coming out of the ocean in the Levitus data. Data is for the top 2,000 metres of water. Note that despite average values being used, both by Hansen and also in the study under discussion, neither the mean nor the trend are statistically significant. Further discussion here.
For current purposes, let me point out that Figure 4 shows that in order for the ocean to gain or lose the energy that is shown in the Levitus data, it requires a very large year to year change in the amount of energy entering the ocean. That energy has to come from somewhere, and it has to go to somewhere when it leaves the ocean. Since the solar input is about constant over the period, that energy has to be coming from a change in either the upwelling longwave or the reflected solar … and we have precise (although perhaps inaccurate) data from CERES on those. Fortunately, the lack of accuracy doesn’t matter in this case, because we’re interested in the year to year changes. For that all we need is precision, and the CERES data is very precise.
So … let me compare the forcing shown by the Levitus ocean heat content in Figure 4, with the CERES data. Figure 5 shows the difference.
Figure 5. Forcing given by the Levitus ocean heat content data, compared to the CERES data shown in Figure 3.
As you can see, they have a couple of big problems with their claims of a consistent 1 W/m2 imbalance over the last decade.
First, it is contradicted by the very data that they claim establishes it. There is nothing “consistent” about what is shown by the Levitus data, unless you take a long-term average.
The second problem is with the Levitus data itself … where is the energy coming from or going to? While the CERES TOA imbalance is not accurate, it is very precise, and it would certainly show a fluctuation of the magnitude shown in the Levitus data. If that much energy were actually entering or leaving the ocean, the CERES satellite would surely have picked it up … so where is it?
I’ve discussed what I see as unrealistic error bars in the Levitus data here. My current comparison of Levitus with the CERES data does nothing to change my previous conclusion—the precision of the Levitus data is greatly overestimated.
Finally, the idea that we have sufficiently accurate, precise, and complete observations to determine the TOA imbalance to be e.g. 0.85 watts per square meter is … well, I’ll call it premature and mathematically optimistic. We simply do not have the data to determine the Earth’s energy balance to an accuracy of ± one watt per square metre, either from the ocean or from the satellites.
Best regards to all,
w.
MY OTHER POSTS ON THE CERES DATA:
Observations on CERES TOA forcing versus temperature
Time Lags In The Climate System
A Demonstration of Negative Climate Sensitivity
DATA:
CERES data: Unfortunately, when I go to verify it’s still available, I get:
The Atmospheric Science Data Center recently completed a site wide redesign.
It is possible that the page you are looking for is being transitioned. Please try back later.
If the page you have requested is still not available, it may have been renamed or deleted.
It is recommended that you use the Search interface on the ASDC Web Site to find the information you were looking for.
Since I got there via the aforementioned “Search interface on the ASDC Web Site”, I fear we’re temporarily out of luck.
[UPDATED TO ADD] I’ve collated the global and hemispheric monthly averages from R into a “.csv” (comma separated values) Excel file available here.
REFERENCES FOR THE NATURE CLIMATE CHANGE ARTICLE:
2. Hansen, J. et al. Earth’s energy imbalance: Confirmation and implications.
Science 308, 14311435 (2005).
3. Trenberth, K. E., Fasullo, J. T. & Kiehl, J. Earth’s global energy budget.
Bull. Am. Meteorol. Soc. 90, 311323 (2009).
4. Trenberth, K. E. An imperative for climate change planning: Tracking Earth’s
global energy. Curr. Opin. Environ. Sustain. 1, 1927 (2009).
5. Trenberth, K. E. & Fasullo, J. T. Tracking Earth’s energy. Science 328,
316317 (2010).
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@ur momisugly George Smith.
1362 W/m^2 is the TSI onto the _disk_ of the earth. When you take into account day and night and the spherical shape rather than a disk you end up with a factor of 4.
The ca. 350 W/m^2 is is average isolation per square meter of earth’s surface.
Lester Via says:
August 30, 2013 at 11:09 am
Actually, the best you can do is break even, it all goes back to heat. Solar electromagnetic radiation is converted into a variety of forms of energy—chemical (via photosynthesis), thermal (via absorption), latent (via evapotranspiration), mechanical (via motion of wind and oceans).
At the end of the day, however, it all turns back into heat. The only question is, how long is “the day”? If the wind blows sand up onto a high ledge, it could sit there for a thousand years. Once it falls back down to the ground, however, the stored potential energy is turned back into heat.
For organic materials, the process is generally faster. When a plant is eaten by a deer, it is turned into heat to keep the deer warm, plus mechanical energy moving the deer around … and the mechanical energy of course quickly turns into heat.
w.
Scarlet Macaws comment…….
The solar and reflected solar would be greatest when the Earth is closest to the sun in the NH winter. The upwelling longwave would be greatest when the land is warmest, in the NH summer. So it’s not surprising the two are 6 months apart.
Quite right, for a concise explanation, refer to John Kehr’s book An Inconvenient Skeptic. Outgoing Longwave Radiation is related to earths surface temperature, not incoming radiation, and that’s governed by NH insolation!
Agree with the physics explains the stability over time. Albedo and other macro phenomena are comprised of quintillions of exchanges of photons across the whole system all the time. No wonder it is always driving so powerfully toward equilbrium. If, instead, we only had a once-a-year settling of accounts –like tectonic plates doing a re-set– the instability would be such that we wouldn’t be here to marvel about it all.
Using the models to calibrate the satellite is like the story of the factory whistle blower and the local store selling clocks. In the morning on the way to work, the whistle blower walks by the clock store to see what time it was and to set his watch. The clock maker ran around and set his clocks on the basis of the factory whistle sound at noon. This works OK for a while until someone from outside their environment shows them the possible growing error.
milodonharlani,
Sorry, I misunderstood you. I see what you’re saying now.
I suppose we have to thank ‘the team’ for bringing a whole new generation of acolytes and hobbyists to a subject they would probably never have heard about otherwise.
They probably would be sad to know that many (including me) would rather listen to Willis than to them.
One would expect a slightly negative balance. Gail’s energy in the extreme UV (apparently not measured by Ceres) would enter the atmosphere unobserved, transform to heat, and get measured on the way out. Similarly energy from gravitation (tides and contintental drift), cosmic rays, micro-meteorites, internal residual heat, etc. would be missing from the “in-box” but measurable in the “out-box” as thermal radiation. It is hard to imagine the Earth radiating much outside of the wavelengths measured by Ceres.
Meh, I think biological / chemical energy storage is probably short by a couple of orders of magnitude.
From here (http://news.mongabay.com/2006/1013-fsu.html) I get phytoplankton storing about 63 terrawatts per year, so order of 10^13. W/m-2 incident on the earth per year ought to be around 10^17 Wm-2, even given that a 5 W/m-2 ‘imbalance’ is about 1.5% of total energy, this still isn’t close.
Oh well. 🙂
Willis says:
Egads, no, that’s throwing the baby out with the bathwater. Precision is valuable even if the accuracy is relatively low.
I grant that high precision is good for detecting changes, but if the absolute measurement is desired, accuracy is required. Since the accuracy is suspect, the CERES data should not be used for anything that requires an absolute measurement (until proper calibration can be done). This is what I meant when I said that data should be thrown out.
It appears the hockey team wants to use the CERES data for absolute measurements, i.e. TOA power measurements. They should be dinged hard for this, but they seem to be Teflon coated.
george e. smith says:
August 30, 2013 at 12:11 pm
These are AVERAGES, george … and part of the time the downwelling solar energy is zero. In addition, they are measured on per square metre, not perpendicular to the sun, but perpendicular to the surface of the earth..
As a result, the inexorable math means that the average of your actual measured sunshine values 24/7 will be a quarter of the instantaneous value …
w.
I’ve consistently posted that satellite data can be used only comparatively and not absolutely, because ground-based observations are needed to callibrate the satellite readings. Hansen’s quote that “Because this result is implausible, instrumentation calibration factors were introduced to reduce the imbalance to the imbalance suggested by climate models, 0.85 W/m2 (Loeb et al., 2009).” is yet another illustration of that — but note that in this case, the calibration was done not to ground-based observations, but to “climate models” — in other words, a complete nonsense. This is where Trenberth’s Missing Heat is, between the ears of the climate scientists.
Willis,
regarding your 12:42 pm post:
I was thinking more along the lines of wood and other organic products that become sequestered. We build wooden structures intended to last a hundred years or more rather than let trees die and rot. Peat bogs sequester organic materials for millions of years to produce the coal we burn today – a process that still occurs. Are there any similar endothermic reactions associated with marine organisms that can sequester solar energy for geologically long time spans?
To Clive Best: I see you’ve quoted “gravitational potential energy”. Don’t go down that road, it leads nowhere. Gravitational potential energy is a fudge factor, like entropy, like dark matter, like dark energy. Don’t go there.
Yes you are probably right about that one …. but I am now trying to work out another effect.
Photons from the sun exert a radiation pressure on the earth of around 10^-5 newtons/m2. That force ends up increasing very slightly the earth’s net distance from from the sun. Work is done – energy is consumed. I expect it is completely trivial but still worth an estimate.
“””””……Willis Eschenbach says:
August 30, 2013 at 1:11 pm
george e. smith says:
August 30, 2013 at 12:11 pm…….”””””””
Well Physics operates in real time.
And in real time, 350 W/m^2, even directly overhead, will not cook an egg; will barely melt ice for that matter.
But 1362 W/m^2 will cook an egg.
On average, tropical storm Sandy didn’t do much damage over its lifetime; just some cherry picked times and places.
Nor did the Hiroshima Atom Bomb for that matter.
Averages, never produce the same result as the sum of the effects of the real values.
You can’t evaluate the atmospheric reflected upward solar spectrum energy at midnight; only in daylight, so who cares what the midnight value is.
That is what is wrong with “Climate Science”.
They say climate is the average of weather; it isn’t, it’s the long term integral of the weather, and those two do not differ simply by a factor of 4.
Greg Goodman says:
August 30, 2013 at 10:30 am
Reflected measured by satellite must be basically specular reflection. What happens when the satellite is looking into the rising sun reflected on open water or areas of melt-water? Does the radiometer get its protective flap closed to prevent it getting ‘blinded’ ?
==============================
Greg — this looks like the kind of stuff you have to work with for a long time to really understand for a given system. As I happen to know from a youth misspent hanging out in dingy computer rooms in the 1960s, solar reflections from the ocean, etc ARE a problem for some satellites in high altitude orbits that are trying to see a lot of the Earth. But I get the impression from Wikipedia (http://en.wikipedia.org/wiki/Clouds_and_the_Earth's_Radiant_Energy_System) that Ceres instruments — of which there have been/are several in orbit — don’t look at the whole visible surface, but instead are scanned over a limited range left/right or fore/aft of straight “down”. Planetary coverage presumably is achieved by the platform’s continuous travel. The Aqua satellite — which is one of the CERES platforms — seems to be in a 98 degree orbit (82N to 82S) at about 600km altitude. I would guess that they do something special during the short periods when the satellite is directly between the sun and the Earth’s surface. It’s not so clear what they do about reflections from tilted surfaces like some icefields or ocean swells. But I’m sure they understand and try to deal with the problems.
NZ Willy says:
August 30, 2013 at 1:29 pm
I’ve consistently posted that satellite data can be used only comparatively and not absolutely, because ground-based observations are needed to callibrate the satellite readings.
###########################################
Lets see.
What does CERES instruments measure.
1. Incoming SW at the TOA.
You measure the incoming solar at the top of the atmosphere.
2. Upwelling SW. this would be the SW that never reaches the ground.
3. Upwelling IR.
To view the calibration activities just look. But before that understand that for some measures a calibration to “ground measures” isnt even the correct thing to do. For example, if you are measuring the SW that enters the atmosphere at the top.
http://ceres.larc.nasa.gov/documents/DP_workshop/pres/priestley.pdf
################################################
Also, I might be instructive to list the actual dataset that was used.
The amount of processing involved in a final product can be rather large.
See page 19
http://www.star.nesdis.noaa.gov/jpss/documents/meetings/2011/AMS_Seattle_2011/Oral/AMS_0111_CERES_4C-1-1.pdf
Michael D says:
August 30, 2013 at 1:02 pm
That was my thought as well … but the balance is positive, not negative. What CERES accounts for as leaving the planet is smaller than just the measured incoming sunshine.
w.
Willis Eschenbach says:
August 30, 2013 at 12:24 pm
” One watt per square metre will heat one cubic metre of seawater by one-third of a degree C per year … ”
I think maybe the units aren’t quite right here Willis. As stated in terms of a flux, we need to know the area over which the flux operates in order to get the change in energy content of the material. If the cubic metre of seawater is in a container that’s 1.0 square metre over which the flux obtains by 1 metre in length, for example, is different from a container that’s 0.01 square metre over which the flux obtains by 100 metre in length. Really extreme containers can be constructed because it’s a continuum all the way down.
Those Joules are tiny things, aren’t they.
Clive: I expect Earth’s orbit is responsive to all forces, gravitational (large) and photonic (tiny). To clarify my previous point, avoid “gravitational energy” notions — nothing wrong with “gravitational potential”. The point is that gravity and energy are completely separate, so keep them that way. Also, gravity does not gravitate — that is more sloppy thinking. Keep your models and equations discrete and crisp — good for your models, good for your head. Am I allowed one more pointer — photons do not interact with anything in mid-flight. Avoid all models which say they do, blind alleys every one of them. Photons are perfect relics of their point of origin.
Willis Eschenbach answers thus:
“Actually, the best you can do is break even, it all goes back to heat. Solar electromagnetic radiation is converted into a variety of forms of energy—chemical (via photosynthesis), thermal (via absorption), latent (via evapotranspiration), mechanical (via motion of wind and oceans).”
‘At the end of the day, however, it all turns back into heat. The only question is, how long is “the day”? If the wind blows sand up onto a high ledge, it could sit there for a thousand years. Once it falls back down to the ground, however, the stored potential energy is turned back into heat. For organic materials, the process is generally faster. When a plant is eaten by a deer, it is turned into heat to keep the deer warm, plus mechanical energy moving the deer around … and the mechanical energy of course quickly turns into heat.’
Wait, let’s suppose the excess energy received by the earth is converted to plant life (say trees). Sure, some of this energy would be released if the trees are burned — but not all of it (second law of thermodynamics). And not all (very much not all) trees get consumed by fire.
Isn’t the difference an increase in entropy (3rd law)?
Four years ago Bob Knox and I published a paper “Ocean heat content and Earth’s radiation imbalance” Go to http://www.pas.rochester.edu/~douglass/papers/Douglass_Knox_pla373aug31.pdf
We discuss the Ceres data and most of the things that Willis mentioned — some in more detail. We even address Response Time (Section 5.3) and “temperature in the pipeline”.(section 5.4)
Nothig has happened since then to change our conclusions
David Douglass
Will-
(Much thanks for previous answer and I ask for your continued patience as I clarify and re-ask)
You said: “The reason is that the amount of heat coming to the surface from the core of the earth is relatively small, on the order of a tenth of a watt per square metre when averaged over the planetary surface”.
Add to that this-(quote from NOAA website)-“The ocean covers 71 percent of the Earth’s surface and contains 97 percent of the planet’s water, yet more than 95 percent of the underwater world remains unexplored.”
So, to me, what you seem to be saying, is that Scientists ONLY measure the amount of heat “coming to the surface from the core of the earth” that is on LAND…ABOVE….WATER. Since that “surface area-LAND” only covers approx 29% of the “earth’s surface” then they are only measuring 29% of the geothermal heat being introduced into the land/sea/air environment , and then averaging that “small amount” over the planetary surface. Correct? Don’t hesitate to tell me I’m wrong.
If I’m right, then they are either oblivious to, or ignoring, 71% of geothermal heat that is actually coming to the surface of this planet!!!!(or stopping at mid point to hover/hide lol)
We didn’t DISCOVER that underwater (ocean) thermal vents even existed until the late 1970’s. Since then, vents have been found in which the water coming out of the vents is around 400 degrees Celsius! They produce “supercritical” fluids, pumping 24/7, that is highly acidic. They percolate where tectonic plates move against each other and spread.
And the heat coming from the vents isn’t all there is….there is evidence now that what scientists thought was NOT POSSIBLE at such depths and such pressures-violent “pyroclastic activity” where lava and debris actually rockets out and up into the water! Such an “eruption” , one categorized to be as big as Pompeii, took place under the Arctic ICE in 1999, according to researchers at the Woods Hole Oceanographic Institution in Mass.
http://www.canada.com/topics/news/story.html?id=81bb2fd3-63f1-476f-b0be-f48c0dc90304
http://www.google.com/hostednews/afp/article/ALeqM5gRI87Fyr-TpE6OBYfAcYxFKSXRJg
http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=1541
The mid-ocean ridge system is something like 80,000 km-long! If there this much volcanic/tectonic/hydrothermal activity in just the 5% of the ocean NOAA considers to be “explored”-can you postulate for me what “most likely” exists (in IPCC terms) on the unexplored remaining 95%?
Your sleuthing is bearing fruit, Willis.
However, maybe the “overall stability of the system” you find interesting is, much like their fudged, model-driven one-watt-per-square-meter radiation imbalance (and the supposed source of invisible, nowhere-found heat), another of Hansen’s “implausible, instrumentation calibration factors” that are applied to keep the system stable, because “everybody” knows, just knows it is!
I wouldn’t trust these government data-gathers any farther than I could toss them. And once you bring this to their attention, don’t be surprised if they don’t have to suddenly “homogenize” the data to make it fit their world view.
(Ooops…I’ve let the cat out of the bag, haven’t I?)