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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Careful Gail; your organizational skills are showing.
Keeping those organized files and knowledge on your desktop is perhaps a tad selfish? Surely there are plans to establish a blog page where your accumulations of carefully filed knowledge gets released for some recreational exercise?
If not, why not? As months have passed, your ability to reach deep and pull relevant detailed information with proper attribution and links has gone past apparent to impressively obvious. An organized index of topical references is wealth beyond imagination.
Can we visitors to WUWT nominate persons for moderation positions? e.g. Gail Combs as reference moderator managing reference pages? This is the kind of enterprise that starts small and works towards large; large enough that WUWT ‘spins’ off wordpress enterprises? Please note Anthony, your reference pages are extremely useful and worthwhile, but still cause one to search for and collate references, links and knowledge. They’re great reference pages but are not topical index references.
Knowledge is the kind of thing people pay cash for. Instead of charging a heady price for access to identified references, charge a small fee, $dollar, Euro, two bits, four bits, or a yearly open access. Perhaps share some of the income with Gail and other volunteers?
In a way, I’m a little envious. I’ve spent hours searching for tidbits I’ve read in the past, collated them, wrote up a small comment or wrote nothing and closed all tabs. I saved nothing for those hours of work, except for knowledge in that gray matter ethereal existence where a person’s knowledge resides and perhaps a PDF or two. It appears, to me, that Gail has worked smarter and efficiently; especially as time progresses.
Just saying…
(and hopefully causing others to think similarly)
We hear that the heat is going deep into the ocean, but…j
A question: Levitus data goes to a depth of 5000m. However, ARGO only samples to 2000m.
Where are the measurements coming from for depths below 2000m?
31556926 seconds per year at 1 watt is 31.5 MJ
Seawater density is 1030 kg per cubic meter times specific heat of 3993 joules per kg-Kelvin
Thats 4.11 MJ per Kelvin
31.5/4.11 is 7.66 Kelvins
Adding 1 watt per square meter adds enough energy to raise one cubic meter of seawater by 7.66 degrees in one year. Seawater in the tropics has a very low albedo.
For land, granite to a depth of 0.1 meters has 2700 kg, times 800 Joules per kgK is 2.16 MJ/K
31.5 MJ/2.16 MJ/K equals 14.6 Kelvins. Thats if all 1 W per square meter is absorbed, but granite albedo is 0.33 so only 2/3 is absorbed. Still, about 10 Kelvins after one year.
Green Sand,
Here is a pdf of the pmod composite going back to 1978, seeming to pulse along with the sunspot number ftp://ftp.pmodwrc.ch/pub/data/irradiance/composite/DataPlots/comp06_d41_62_1302.pdf
Seems to be decreasing, but that could be an uncorrected artifact of satellite variation.
More reading here.
Willis, regarding your discussion with Aphan, there was a post on the internet where a Robert van der Hilst of MIT did a measurement of the Earth’s internal temperature and found it to be 6,650 F. The article appeared in the March 30 issue of the journal Science. I don’t think that the scientist worked with the climate but he was quoted as saying “From their measurements, the scientists estimate that about one-third of the heat that radiates from Earth’s surface into the atmosphere—estimated to be 42 terawatts—comes from our planet’s core.”
http://www.livescience.com/7239-earth-temperature-hot.html
What a wonderful succinct description of ‘rgbatduke’s’ comment;
rgbatduke’s comment blows past easy understanding for me when reading en bloc. As I illustrate with part of rgb’s comment, I have to break it down to components so I can work through the process without getting cross-eyed; I do this often for many of the technical articles and comments as I never understand the climsci insistence on en bloc single spaced writing, or worse the climsci team’s insistence on massive disjointed disconnected ramblings posing as official research. N.B., no amount of dissection or organization improves many of their writings.
Kaleidoscope, http://arbrealettres.files.wordpress.com/2009/11/kaleidoscope2.jpg
Similar to Willis’s response to rgb, I was puzzled about the averaged averages regarding earth’s changing insolation, orbit, wobble, orbiting altitude of Ceres in relation to atmosphere, IR atmospheric processing delay, if any, in exiting our atmosphere ; when rgb dropped his kaleidoscope of questions. This puzzled ATheoK needs time to sort out and think about Willis’s article and many questions raised following the article. This isn’t digestible, to me, with one gulp.
Great article Willis! As all too often, your insight, effort and detail makes one wonder just where in blazes is research along these veins done by the ‘inside experts’?
Steve Mosher, thank you for the comments and links. I’ve added them to the pile I want to digest while thinking this over.
Hey, where did the ‘preview’ option go? I liked that choice. Is it causing too much bandwidth with WP?
Annual average net radiation and Annual average net cloud radiative forcing.
http://earthobservatory.nasa.gov/Features/Clouds/clouds6.php
The Sahara and Arabian deserts are large net +ve radiators. That is they lose more heat than they gain.
Hmmmn. On the actual measured “accuracy” of their “assumptions” about their radiation data…
This copied from the “Summary” of just one peer-reviewed source of measured radiation data over several years at the same spot near the equator: Only 9% repeatability between yearly data? And two months were only 6% different!
Yet Hansen insists they need to “change the measurements” to fit the model to two decimal places.
Summary
In addition to global solar radiationE ↓ g , the hourly diffuse componentE ↓ d incident on a horizontal surface has been measured from February 1993 to January 1995 at a meteorological station in tropical West Africa. The measured diffuse solar irradiance data was corrected for shadow band effects. The monthly mean diurnal variations of diffuse solar irradiance obtained for identical months in the two years have been compared and found to be generally consistent. The corresponding monthly mean hourly values ofE ↓ d for identical months in 1993 and 1994 agreed to within 9% while yielding correlation coefficients greater than 0.960. In addition, the monthly mean daily totals ofE ↓ d for identical months were found to agree mostly to within 6% and showed virtually the same annual variations in both years. The monthly mean daily total values of diffuse solar radiation for most months in the two years ranged between 7.94 MJm−2d−1 and 10.50 MJm−2d−1. The monthly mean of daily hourly maximum values ofE ↓ d obtained for identical months in the two years have been discussed in relation to the dominant atmospheric conditions during these months. The results been presented here have been compared with those of some investigators within and outside the Africa region.
From Meteorology and Atmospheric Physics
1999, Volume 69, Issue 3-4, pp 223-230
On the annual and monthly mean diurnal variations of diffuse solar radiation at a meteorological station in west Africa
M. G. Iziomon,
T. O. Aro
“”””””…..Greg Goodman says:
August 30, 2013 at 6:51 pm
Philip Bradley says:
Solar reflection is mostly due to clouds, and while clouds vary in their reflectivity, clouds that reflect incoming solar upward will also reflect outgoing LWR downward.
===……””””””
Well clouds, are either water droplets or ice crystals, so both are quite transparent to the visible solar spectrum. So they do not “reflect” solar spectrum energy. They transmit it, and scatter it into a wide angle essentially isotropic angular distribution. After going through just three water droplets, the ray direction is quite unpredictable.
As for ground emitted LWIR, the clouds also do not “reflect” LWIR radiation. They completely absorb it in about 50 microns of water/ice thickness, that 2/1000ths of an inch. Then the water of the clouds, either solid or liquid, reradiates a thermal spectrum that is dependent on the local Temperature of the clouds, and once again, that is isotropic.
“””””……Milwaukee Bob says:
August 30, 2013 at 5:13 pm
george e. smith says:
August 30, 2013 at 1:40 pm
They say climate is the average of weather; it isn’t, it’s the long term integral of the weather, ….
So George, describe the climate outside your window right now, without using any weather terms……”””””
Well the climate outside my window (it’s dark at 2120) is exactly what you would expect to get after around 4.5 billion years of earth weather, and geology, and biology.
Pretty nice and highly habitable.
The weather is CAVU except its dark, and also windless. We don’t have stars in the Sunnyvale CA night sky, so can’t comment on those.
Our forest fire worry worts say we have unusual droughts. No they aren’t unusual, Ca is a natural desert State. The airlines park all their excess air liners, ready to put back into service, once the Obama Economy Recovery finally kicks in; at the Mojave airport in socal, because it is dry, so they don’t corrode away.
ATheoK says:
August 30, 2013 at 8:28 pm
http://catalogx.ensmp.fr/Files/ESRA11res.pdf
THE EUROPEAN SOLAR RADIATION ATLAS
Vol. 1: Fundamentals and maps
K. Scharmer and J. Greif 2000
Has a good solar primer in its nbr 2 and nbr 3 chapters. Shows the grpahs of these equations, their derivations, and the geometry involved in what rgb and Willis have written. Chapter 4? Less usefull: It is about example of the solar radiation data plots that the ESRA CD produces if you buy it.
No – No, you can’t “get it” from these equations above immediately and easily, but they are understandable. Earth goes around sun, but at different distances. Energy available at top of atmosphere – before it gets absorbed or reflected or changed – depends on how far from the sun the earth is on any given day.
Once you get to the average earth at the top of atmosphere, you have to get through the atmosphere. Could be reflected, absorbed, or bounced back and forth a little bit. The length of atmosphere you have to penetrate to get to the surface depends on how in the sky the sun is, which depends on what day of the year it is (how much declination there is) and how far above the horizon the sun is at that moment, and what latitude you are at. So, at noon on the equinox (Sept 20, March 20) the sun is high in the sky, and the declination is near 0.0, but you still get less solar energy at polar latitudes than near the equator. (Did you notice the above “average” solar radiation ignores ALL of these inconvenient “facts”? ) But, at noon at Dec 21 or June 21, the declination is higher, and at the same location on earth (same latitude as before) you would get less radiation on the surface. But, on both of those days, you are nearer or further! from the sun than on the equinoxes, so the top-of-atmosphere radiation has changed even more. Go earlier in the day (near dawn) and there is much more air mass, more radiation lost in the atmosphere. Set nearer sunset, same thing: more air mass, less radiation available.
Go higher in latitude, and the average height of the sun every day changes: This is one more term to throw in: the latitude correction for a flat surface like the ocean, ice, or a plate on the ground.
It changes every day, at every latitude, at every time of day. But remember, Hansen wants just one correction – from his models TO the data! – for all of the world for all latitudes, for all days of the year, for every hour of the day!
Nice little interactive for you, george.
@Keith. Minto.
I have ray traced the rain drop many times. I also have ray traced a monofilament fishing line under water. Lots of fishermen think that fluorocarbon leaders, have low visibility for fish compared to nylon leaders, so they aren’t spooked from your fly.
It’s nonsense. The fluorocarbon index isn’t near that of water, though closer than nylon.
So the leader blocks the overhead sun, leaving a shadow zone behind it. But the light transmitted through the leader is focused into a bright line near the leader in that otherwise shadow zone.
A highly practical fly fisherman sits under water in rivers, with scuba, and video camera, and has taken video movies, of that flashing line image of the sun, running up and down the leader, and yes the trout spook off it.
The reflections shown in your action flick are simply 2-3% or so regular Fresnel reflections, but the 97-98% transmitted light is focused by the droplet into a very wide angle image of the sun, so most of the transmitted light is converted from a near collimated beam into a strongly focused beam, that then expands into a highly diverging beam, and can then hit another droplet. So the “rainbow condition” does not tell the full story, it is the strong focusing of the transmitted light that is responsible for the wide angle scattering.
We can’t post pictures here or else I could show you what an actual ray traced sun image looks like in a rain drop, or cloud droplet.
“”””””……ThinkingScientist says:
August 30, 2013 at 3:36 pm
George E. Smith, is this you?
http://en.wikipedia.org/wiki/George_E._Smith……””””””
NO. my middle E is for Edward. I know people who know both of us. You might find something browsing around the University of Auckland website, but they have it fairly well hidden.
The initially ‘odd’ phase relationship is probably a reflection of N/S land ration and perihelion = NH winter.
Difficult to say from Fig 3. It looks like the graphed lines have been compressed horizontally as they are shorter than the x axis, and the title says 60 months data which is what is shown on the x axis.
Talking of watts/sq metre, read an article in Telegraph re wind power stations in UK. One power (joke) plant,capable of producing 5.6 megawatts, was producing 6kw. Yes, 6 kw. at the same time, another was producing MINUS 10kw. And, wait for it, at the same time,another was producing MINUS 80kw. Yes,taking power out of the grid. Hope people didn’t want water for tea/coffee
George E Smith.
Thanks for the response, appreciated.
I think I found you. It was the salt water fly fishing reference that probably clinched it…
As you post under your real name I was curious about your background, because your comments about the actual insolation, not averages, (and other commenters elsewhere) are getting my attention in trying to unravel some of the correct physics. I am very concerned by the 255K is proportional to 1365/4 therefore GHE =33K argument as I think it is non-physical.
A point you didn’t mention about fluorocarbon, which I found out the hard way! As a youth I fly fished a lot, nylon leaders being the only available then. I stopped fishing for a while, but in later life have fished again. Switched to fluorocarbon leaders, attempted to trim loose end from hook with teeth (as I was accustomed with nylon) and now have permanent notch in tooth to remind me that fluorocarbon is very hard!
Model-based evidence? Is that like speculation-based fact?
Great stuff, Willis!
If I understand this article correctly, it seems to me that this is a fairly strong refutation of the SkS kidz’ meme du jour that “there is an energy imbalance in the climate system equivalent to 4 Hiroshima bombs exploding every second…, and that energy is finding its way into the deep oceans”.
Am I correct in that understanding, or have I got the wrong end of the stick?!
Photosynthetic efficiency of plants range from 0.1 to 8%. That is the proportion of shortwave radiation that is converted into biomass. I don’t know what are the values for the ocean, but surely part of that downwelling solar radiation is converted into biomass. I don’t know whether that have a measurable impact in the radiation balance.
rgbatduke says:
August 30, 2013 at 11:08 am
…I have a hard time seeing how there can be a reflection peak in phase with the insolation that doesn’t produce a similar shaped trough in the LWIR….
First the relation between The insolation and the reflection; the reflection is an immediate respons to the insolation, so that these two curves are in phase should not be surprising. The difference between perihelion an aphelion is not so big that it effects the total continuos picture.
Since the insolation differs a bit (because of the orbit) it is interesting that the outgoing LWIR has a smilar but lagged pattern.
The insolation and the reflection starts with a high peak, so I guess this must a perihelion phenomenon, and at this time of the year it is high summer in the southern hemisphere, the start of january. Most of the land masses are in the nothern hemisphere, more ocean in the southern. Would it not be more light reflected from land and more absorbed by the sea in general due to the heat capacity of the ocean? Well, the summer in the southern hemisphere is when the earth is in perihel, and it is now the sea is heated there. At least a certain lag of outgoing LWIR must be expected, wouldn’t it?
Merovign says:
August 31, 2013 at 12:36 am
Model-based evidence? Is that like speculation-based fact?
=================
ROFLMAO
Quote of the day
Willis,
Your plot shows downwelling solar at the TOA to be varying by around +/-10W/m^2 over the seasonal cycle.
The shape of the Earth’s orbit is elliptical, with the Sun near one focus.
As a result, Earth’s distance from the Sun (center-to-center) varies with mean values of 147,098,074 km at perihelion (closest) to 152,097,701 km at aphelion
Difference is 4,999,627 which is 7.48% of the average Earth-Sun distance.
Radiation from the Sun drops off with the inverse square law.
At average Earth distance and average solar irradiance we receive ~1361.5 according to TIM/SORCE
Therefore the Downwelling solar at TOA will vary by 37.24W/m^2 over the year or +/-18.6W/m^2
Is the discrepancy due to some attenuation of the solar signal above TOA that the source for your figures accounts for? If so there must be some interesting energy-chemistry dynamics going on up there, because this is a huge amount of energy.
Thanks
TB
Greg Goodman says:
August 30, 2013 at 4:13 pm
Don K “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. ”
Thanks Don. So that orbit with essentially downward looking instrumentation means that it will NEVER measure surface reflection from low incident angles. It is not correctly measuring reflected SW and therefore will produce a net warming imbalance.
==========================
Yep, That’s pretty much what I’m currently thinking also. But it’s such an obvious issue that it seems improbable that it has been overlooked. Not that there isn’t a lot of questionable “science” in the field of climate science, but simply overlooking low angle radiation seems pretty odd even for a bunch of folks who genuinely don’t seem to know what they are talking about much of the time. There’s probably something I/we don’t know or haven’t thought through.
==========================
Sea water that would normally absorb almost all incoming solar will reflect as much as 90% at angles of incidence less than 10 degrees: conditions that can be found in polar regions for several months of the year.
==========================
I’ve seen charts that show a fairly sharp breakover from absorbtion to reflection between incidence angles of 40 and 50 degrees for both water and ice. For water at least, that fits well with what I observe when I approach pools of rainwater. Initially, I see reflections of objects beyond the pool. When I get close, the reflections fade fairly abruptly (reduced reflection I assume) and objects under the surface become visible. I’ll try to remember to check the situation for ice the next time we have an ice storm.
Ah, just spotted you’ve got the 1361/4 to get your 340.