The Congo vs. Sahara-Sahel once more

UPDATE, June 19, 2017: The new ‘CERES EBAF Ed4 Sfc’ dataset arrived in May. The updated version proves even more detrimental to the idea of an “enhanced GHE” than the older one. The average sfc radiant heat loss (net LW, OLR) in the Congo is now reduced from 51 to 34 W/m2, while the same flux in the Sahara-Sahel has increased from 103 to 107 W/m2. At the same time, the solar heat inputs (net SW, ASR) in both regions are now more or less equal: 173.6 W/m2. Which means that the tropospheric column above the Congo surface appears to restrict its radiant heat loss to less than a third (rather than ‘just’ half) of its equivalent flux in the Sahara-Sahel region. So with the same heat INPUT from the Sun, but with a radiant heat loss more than three times larger (!) per unit time than in the Congo, the Sahara-Sahel surface is STILL several degrees WARMER on average than in the Congo!


OK, so commenter “Norman” asked me at Roy Spencer’s blog to clarify my position on whether a “more IR active atmosphere” would necessarily produce a higher average annual surface temperature at the bottom of that atmosphere. His inquiry in full:

Kristian

Then you would also agree that increasing GHG in the atmopshere (the quantity makes a difference since it decreases the heat out) will lead to the end result of a warmer surface?

Good. That is what the basic point is all about.

Does the amount of GHG in the atmosphere change the equilibrium temperature of the Earth’s surface?

In your other writings you have states some GHG is necessary but the quantity does not matter. what is your current understanding?

More GHG warmer surface?
Less GHG cooler surface?
Or No change once a certain amount is present?
If in both cases the solar flux to surface remains the same.

So what do we mean by a “more IR active atmosphere”? Well, a proponent of the AGW idea (that of the anthropogenically “enhanced GHE”), like Norman here, would simply say: more “GHGs”. But what does this actually entail? It would lead to an atmospheric column that is more opaque (that is, less transparent) to outgoing surface IR. The idea is that the so-called “GHGs”, the IR active gases (and clouds, mind you), would absorb it more strongly, sort of “capture it” on its way out, and reradiate it in ALL directions, not just the upward one, thus diminishing the net flux of IR moving away from the surface and in the direction of space. And what is this net flux of outgoing IR from the surface? It’s the surface radiant HEAT loss, its Qout(LW).

So Norman’s central claim is this one: “(…) increasing GHG in the atmopshere (the quantity makes a difference since it decreases the heat out) will lead to the end result of a warmer surface (…)”

Well, will it? What does empirically based data from the real Earth system have to say about it?

We return to Africa. My original post discussing this particular issue is here.

Here are my two regions up for direct comparison. Note how the map in Figure 1 shows annual average temps at the surface. It is pretty clear from this map alone that the overall surface temperature within the Sahara-Sahel rectangle (upper one) is considerably higher on average than the one witin the Congo rectangle (lower one); I would say, by around 3K:


Figure 1.

The Sahara-Sahel region lies outside of the equatorial convergence zone, but still well within the tropics/subtropics, with a lofty thermal tropopause and a high mean solar input. It sits a bit past midway towards the typically arid zone of the Sahara proper at the bottom of the descending limb of the northern Hadley Cell. The Sahara-Sahel itself is climatically a semi-arid region.

The Congo, on the other hand, straddles the equator, right in the convergence zone, at the bottom of the Hadley Cell’s ascending limb, and is thus very much deep within a highly humid environment:


Figure 2.

Now let’s check out the radiative fluxes for each region.

I will use two datasets, one for the surface (indirectly derived values; estimated from various relevant direct observational sources, such as tropospheric temperature, humidity and cloud profiles), and one for the top of the atmosphere (ToA) (directly observationally derived values).


First we look at the radiant heat fluxes at the ToA. That’s the net incoming SW (from the Sun to Earth), the ASR (Qin(SW)), and the net outgoing LW (from the Earth to space), the OLR (Qout(LW)):


Figure 3. Mean incoming SW (SORCE), top, and mean outgoing (reflected) SW (CERES), bottom. The latter represents the total albedo (atmosphere+surface) of the region in question, the Congo.


Figure 4. Same as Fig.3, only for Sahara-Sahel.

There’s a lot of interesting information to be found in these plots, but we’ll skip most of it for now, for the sake of leading rather quickly up to the main thrust of our argument.

If you take the incoming minus the outgoing SW (Fig.3 and Fig.4), you get the net value, which is the “absorbed solar radiation” (ASR), the actual solar HEAT input to the Earth:


Figure 5.


Figure 6.

You will notice how the mean solar heat input at the ToA above the Congo is substantially larger than the similar one above Sahara-Sahel, 286.64 vs. 268.5 W/m2, to be exact, an excess of 18.14 W/m2 in favour of the Congo. And don’t forget now, this is after having accounted for total albedo. ASR (the solar heat) always includes the albedo.

It would be apposite to compare now the Qin(SW) at the ToA (Fig.5 and Fig.6) with the Qout(LW) at the same level. Earth’s heat loss to space is – for all intents and purposes – equal to the OLR (“outgoing LW radiation”) at the ToA. Globally, these two terms should balance in a steady state. Regionally, however, they don’t need to. And normally, they won’t. Let’s have a look:


Figure 7.


Figure 8.

So what do we see?

The radiative heat balance at the ToA above the Congo looks like this: IN, 286.64 W/m2; OUT, 225.2 W/m2. Surplus: +61.44 W/m2.

The radiative heat balance at the ToA above Sahara-Sahel looks like this: IN, 268.5 W/m2; OUT, 279.25 W/m2. Deficit: –10.75 W/m2.

How can this be? And how can it be sustained in a steady state?

The simple answer is of course that each region also has other heat gains and losses beside the radiative ones. The TOTAL heat balance must always be close to 0 in a steady state, even regionally, otherwise the average temp would just spiral away indefinitely and out of hand. Above the Congo, the tropospheric column appears to “hold back” radiative heat to space, but the energy does in fact escape the region, transported out and away rather via atmospheric divergence high up towards the tropopause (Fig.2). Conversely, above the Sahara-Sahel region, the tropospheric column appears to “over-release” radiative heat to space, but what really happens is that the excess energy thus radiated is transported there advectively from the Equator; from the Congo, so to say.

This process is very well described here:

Air convected to the top of the troposphere in the ITCZ [InterTropical Convergence Zone] has a very high potential temperature, due to latent heat release during ascent in hot towers. Air spreading out at higher levels also tends to have low relative humidity, because of moisture losses by precipitation. As this dry upper air drifts polewards, its potential temperature gradually falls due to longwave radiative losses to space (this is a diabatic process, involving exchanges of energy between the air mass and its environment). Decreasing potential temperature leads to an increase in density, upsetting the hydrostatic balance and initiating subsidence. The subsiding air warms (as pressure increases towards lower levels), further lowering the relative humidity and maintaining clear-sky conditions. However, although the subsiding air warms, it does not do so at the dry adiabatic lapse rate. Continuing losses of longwave radiation (radiative cooling) means that the air warms at less than the dry adiabatic lapse rate (i.e. some of the adiabatic warming is offset by diabatic cooling).

In colloquial terms, one could put it like this: The tropospheric column above the Congo heats (very strongly) from solar input, and cools (weakly) from radiation AND (quite strongly) from advection, while the tropospheric column above the Sahara-Sahel region heats (quite strongly) from solar input AND (weakly) from advection, and cools (very strongly) from radiation.


Well, on to the surface.

The heat IN (Qin) to the surface is again simply equal to the solar heat, the actually absorbed solar radiation, the ASRsfc, which is the downwelling SW minus the reflected SW (albedo) at the surface itself. (Note, we always use the All-Sky values, because this is what represents the situation as it really is (clouds included)):


Figure 9. The downwelling SW to the surface in the Congo is relatively small. The intervening atmosphere (between ToA and sfc) has absorbed about 112 (36%) of the 312 W/m2 worth of downwelling SW entering the Earth system as a whole (through the ToA) that was not reflected by/in the atmosphere itself (~105 W/m2). However, the surface albedo in the Congo also happens to be remarkably low, so as you can see, a relatively small portion of the downwelling SW reaching the surface is reflected back out.


Figure 10. In comparison, the downwelling SW reaching the surface in the Sahara-Sahel region is much higher. The intervening atmosphere has only reflected ~37 W/m2 and absorbed ~89 W/m2 (25%) of the originally incoming SW at the ToA, but at the same time, the surface albedo is much higher than in the Congo, and so a much larger portion of the downwelling SW reaching the surface is reflected back out.

What, then, does this all mean to the average solar heat inputs to the Congo vs. the Sahara-Sahel surfaces?


Figure 11.


Figure 12.

As you can see, the mean values end up being close to identical. The average solar heat input (Qin(SW)) to the surface is 0.88 W/m2 larger in the Sahara-Sahel region than in the Congo, which means the two are within about 0.5% of each other. Practically the same …


Now we’re finally coming to the crux of the matter. What do two tropospheric columns of such vastly differing IR opacities, one semi dry and clear and one highly humid and cloudy, do to the surface radiant heat LOSS (Qout(LW)) in two regions such as the ones under study? We now know that the average surface heat GAIN from the Sun is pretty much equal in both areas. And we know that this heat gain must somehow, in a steady state, be balanced by the average heat LOSS from the surface.

So what happens when the tropospheric IR opacity goes up? What happens to the heat loss? And what happens to the average surface temperature as a result?


Figure 13. The UWLWIR (upper, brown curve) about 450 W/m2, the DWLWIR (lower, red curve) about 400 W/m2.

The UWLWIR values are independent of All-Sky vs. Clear-Sky conditions, because they are computed directly from the surface temperature only. In most cases, and it seems to also be the case here, the surface emissivity in these calculations (similar to the ones performed in regular pyrgeometer ‘measurements’) is assumed to be 1. If this is true, then the mean sfc UWLWIR value for the Congo (Fig.13) gives (through the Stefan-Boltzmann equation) an average surface temperature of 26.1 °C. Likewise, the mean sfc UWLWIR value for the Sahara-Sahel region (Fig.14) gives an average surface temperature of 28.9 °C. That’s a difference of 2.8 degrees, close to the 3 that I suggested at the beginning of this post from eyeballing Fig.1. You can go back and verify for yourself. It seems to accord very well with that temperature map …


Figure 14. The UWLWIR (upper, brown curve) about 470-475 W/m2, the DWLWIR (lower, red curve) about 370-375 W/m2.

So what do we end up with? Net LW in both cases. The surface radiant heat loss:


Figure 15.


Figure 16.

Yup. So our suspicion has been confirmed. The average surface radiant heat loss in the Sahara-Sahel region is about TWICE the average surface radiant heat loss in the Congo.

Anyone surprised?

The highly humid and cloudy tropospheric column resting on top of the Congo surface reduces its radiant heat loss by … A LOT! Compared to the radiant heat loss from the Sahara-Sahel surface, which lies rather at the bottom of a fairly dry, fairly clear tropospheric column.


OK. So at this point the situation at the surface looks like this:

  • The Congo: Heat IN (Qin(SW)), 177.96 W/m2; radiant heat OUT (Qout(LW)), 51.08 W/m2. Missing: 126.88 W/m2.
  • Sahara-Sahel: Heat IN (Qin(SW)), 178.84 W/m2; radiant heat OUT (Qout(LW)), 103.13 W/m2. Missing: 75.71 W/m2.

Still, we know that the heat IN is balanced by the total heat OUT in both regions. The surface heat loss, after all, is not restricted to radiation. We also have conductive and evaporative losses, Qout(cond) and Qout(evap). In the Congo, these other heat loss mechanisms will have to take care of the 126.88 W/m2 that are left after we have accounted for the radiative loss. In the Sahara-Sahel region, however, they will only have to rid the surface of an additional 75.71 W/m2, about 51 W/m2 less.

So what kind of effect on the average surface temperature would such a striking difference have? If the radiant heat loss of the surface is that much reduced from having an atmosphere on top with a much higher level of IR opacity, then wouldn’t we expect this to somehow result in substantial surface warming? Wouldn’t the surface have to warm in this case so that the other available mechanisms are able to work at a higher level of efficiency, simply forced to by the reduction in the radiative loss?

Isn’t this exactly the idea of how the “enhanced GHE” is supposed to force the surface to warm towards a new and higher equilibrium temperature, to make up for a reduction in radiative heat loss?

So how come the average surface temperature in the Congo is almost 3 degrees LOWER than in the Sahara-Sahel region!? With as much heat coming IN, but with much, much less radiant heat going OUT. Why hasn’t this circumstance forced the average surface temperature in the Congo to be much HIGHER than in the Sahara-Sahel? As per standard AGW ‘logic’.

  • The Congo, sfc:
    – Heat IN, 177.96 W/m2.
    – Heat OUT, [51.08 (net LW) + 126.88 (cond+evap) =] 177.96 W/m2.
    – Heat balance.
    – Mean temp: 26.1 °C.
  • Sahara-Sahel, sfc:
    – Heat IN, 178.84 W/m2.
    – Heat OUT, [103.13 (net LW) + 75.71 (cond+evap) =] 178.84 W/m2.
    – Heat balance.
    – Mean temp: 28.9 °C.

Conclusion:

Increasing the IR opacity of an atmospheric column sure reduces the radiant heat loss from the surface underneath. But it most certainly doesn’t thereby necessarily force the average surface temperature to rise. Because there are also factors OTHER than pure radiation involved.

Theory, meet Reality.

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13 comments on “The Congo vs. Sahara-Sahel once more

  1. Norman says:

    Kristian

    I do like your analysis and I can’t see anything I disagree with.

    Evaporation would explain and increased convection (air rising there sinking in the Sahara) the cooler temperature between Congo and Sahara.

    Water is the complex beast. Your graphs show what I find. Less radiation (Net IR, heat) can leave the surface in a humid environment. But water vapor can become clouds choking off solar input which I see in the graphs I look at from the ESRL web site, the solar downwelling if really sporadic in a cloudy region.

    The difference between water vapor and carbon dioxide is that carbon dioxide does not form any clouds or cool via evaporation. An increase of this molecule would only end up reducing the heat flux that could leave the Earth surface with no counterbalancing cooling affects.

    That is why the assumption is that CO2 would lead to some warming. How much is very controversial and I side with lower values.

    • okulaer says:

      Norman, nice to see you here.

      You say: “The difference between water vapor and carbon dioxide is that carbon dioxide does not form any clouds or cool via evaporation. An increase of this molecule would only end up reducing the heat flux that could leave the Earth surface with no counterbalancing cooling affects.

      That is why the assumption is that CO2 would lead to some warming. How much is very controversial and I side with lower values.”

      I agree. CO2 acts nothing like H2O. Either way, on Earth, H2O is the only “GHG” of importance. You could remove all the other IR active gases and it wouldn’t change a thing. Water takes care of everything.

      On other planets it’s different. The atmospheres on Mars and on Venus both contain about 95-96% CO2. However, on Mars this doesn’t result in a rise in Ts above the Te at all. Ts is 7-9K LOWER than Te. On Venus, on the other hand, Ts is hundreds of degrees higher than Te. Why do you think that is? The only real difference is the MASS of the bulk atmosphere.

      I challenge you, Norman, to present empirical evidence from the real Earth system showing how the global rise in atmospheric CO2 (and H2O) over the last 32+ years has resulted in an “enhanced GHE” forcing the GAST to rise.

      Consider this plot:

      It shows how the rise in atmospheric CO2 and H2O has produced exactly ZERO “enhancement” of the “GHE” over the period in question. Earth’s OLR has simply increased in step with tropospheric temps. And that’s it.

      OTHER factors obviously negate any net radiative effect …

      • Norman says:

        Kristian

        You have in your post that Mars effective temperature is higher than its actual measured surface temperature but this source claims Mars has a 5 C GHE. The effective temperature is 212 K but they have the observed Martian surface temperature at 218 K.

        If you have a 18% GHE from CO2 (no clouds or WV overlap) of the Earth’s 33 K speculated GHE you would have the a GHE of 5.94 K which is close to what is observed for CO2.

        • okulaer says:

          No. I discussed this issue with Tim Folkerts some time ago. This is what I wrote back then:
          http://www.drroyspencer.com/2016/07/the-warm-earth-greenhouse-effect-or-atmospheric-pressure/#comment-218940

          Tim Folkerts says:

          This is only part of the story. A real planet will have a lower average temperature (Ts) than the effective BB temperature due to uneven heating and uneven temperatures. So we would expect Ts to be well BELOW Te on Mars. The fact that Ts is actually a bit ABOVE Te suggests the GHE does have an effect.

          Ts on Mars is not above its Te. That’s just what has always been assumed simply from the fact that the atmosphere contains a lot of CO2 (so it must warm some from “back radiation”, right?). There is, however, no real-world empirical evidence of the normally claimed ~5K global “GHE”. It is just stated.

          In fact, satellite measurements suggest a Ts on Mars significantly lower than its Te (calculated from avg TSI minus avg global albedo).

          The Ts can be estimated from global satellite measurements spanning from the late 90s till today (TES, IRTM, MCS) and is (somewhat furtively) provided in at least two available papers.

          First there’s Fenton et al., 2007, comparing IRTM and TES:
          http://depts.washington.edu/marsweb/papers/PDFs/Fenton-etal-2007-warming-albedo-changes.pdf

          Then there’s Bandfield et al., 2013, comparing TES and MCS:
          http://faculty.washington.edu/joshband/publications/bandfield_mcs_tes.pdf

          The relevant tables and figures:
          # Fenton, Table 1.
          # Bandfield, Table 2, Figure 6.

          The Ts of Mars appears to be, based on these estimates (and, in the latter case, extending them all the way to the poles), to be around 202-204K. If so, then 7-9K lower than the planet’s Te in space (~211K) …

          The definition of a “radiative GHE”, Folkerts, is simply Ts > Te.

          The ‘problem’ of the Martian atmosphere is not that it contains too little CO2. It’s rather that it contains too little overall MASS.

          * * *

          You notice the pattern? The Moon has no real atmosphere, thus exhibiting huge temperature swings, both temporally and spatially. And so, as a result, its Ts is much lower than its Te. Mars does have a massive atmosphere, but it’s very thin, and the planet thus still experiences pretty large temperature swings (although definitely not as large as the Moon). As an apparent result, Ts on Mars is still a bit (but not much) lower than its Te. Earth has an atmosphere with a fair amount of mass, much thicker than that of Mars, and its spatio-temporal temperature swings is much depressed as a result. Earth’s Ts is also a bit higher than its Te. Titan is within the same ballpark as Earth (from having a thicker (but not much thicker) atmosphere, but a much lower lapse rate). Its Ts is a bit higher than its Te, but not much. Venus, on the other hand, has a hugely massive atmosphere, its surface temperature swings close to zero as a result. And its Ts is much, much higher than its Te.

          The atmospheric mass (pressure/density) seems to ‘force’ a planet’s “ERL” upward, from ‘below’ the surface to high above it.

      • Norman says:

        I am working on interpreting your graph but it does show a global warming signal just as Roy Spencer’s work shows. On Roy’s graphs it looks like an uptick of about 0.4 C over his time period which needs to be accounted for with something. Carbon Dioxide could at least be a contributing factor. Clouds are another big unknown. The Arctic Ice has declined (not currently) but from the 70’s to today it did take a noticeable average decline. Some increase in energy must be at play in order for such effects. I have read about some weather phenomena as the cause but that would only explain one given year or another. Weather events do not persist for a 30 year time frame.

        One way I calculate the GHE from CO2 (without complex models). If you accept the David Appell links that they have measured an increase in DWIR Clear sky because of CO2 at 0.2 W/m^2 with and increase in CO2 over that time of 22 PPM. A doubling of pre-industrial CO2 would be 280 more PPM (from 280 to 560). 280/22 = 12.73 times greater. Multiply this ration by the amount of DWIR increase that has been observed and you get a value of 12.73 x 0.2. The increase in DWIR (would actually be lower because of the log nature of CO2 emissivity but it just makes getting ballpark calculations easier). You would end up with a value of 2.55 W/m^2 more DWIR than pre-industrial. I know you use the Heat flow and that is okay. Even if it is not what actually is going on it does make for easier calculations. Earth emissivity is actually around 0.96. Plugging all into a Stefan-Boltzmann online calculator the 2.55 additional DWIR would add 2.55 W/m^2 to the UPIR (just for ease I will assume evaporation and convection remain constant…in reality they would probably adjust some).

        My calculations give a 0.46 C increase with a doubling of Carbon Dioxide alone (no feedbacks). I guess this is called the Plank feedback, just CO2 alone.

        This seems to support the work of these individuals.
        https://www.omicsonline.org/open-access/analytical-approach-to-calculate-the-heat-fluxes-in-the-atmosphere-and-to-quantify-the-sensitivity-of-earth-temperature-due-to-co2-2157-7625-S5-012.pdf

        They calculate a 0.42 sensitivity with a doubling of CO2 and no feedbacks.

        I will keep working on it. I have changed my mind many times on climate science and I continue to investigate the science behind it.

        • okulaer says:

          There is only ONE relationship you need to grasp, Norman, and that is the OLR vs. tropospheric temps over time. If the OLR simply tracks tropospheric temps over time, similar to what we observe, then there is no “enhanced GHE”, simple as that. OLR must be observed to trend lower than tropospheric temps over time if one wants to conclude that the operative “greenhouse” warming mechanism has even a potential effect on anything. You can see this particular relationship here:

  2. Norman says:

    Kristian

    I am trying to understand the graph you posted in your last reply with the doubling of CO2. From that graph it would not support your logical conclusion.

    Your claim is that Outgoing Longwave IR should go down with increasing surface temperature if the GHE were “real”.

    The graph would show the surface temperature can increase and the outgoing Longwave IR stays the same.

    The change to measure would not be outgoing IR but the height of the emission. If the height of the emission is going up the GHE is shown to work.

    A hotter surface raises the entire temperature of the troposphere leading to a higher emitting altitude but the IR outgoing flux would be the same 240 W/m^2 and would not show any change.

    I need to think on it more or hope you can explain what I am seeing from your graph.

    • okulaer says:

      Norman, you say:

      Your claim is that Outgoing Longwave IR should go down with increasing surface temperature if the GHE were “real”.

      No, that’s not what I said. Read it again: “OLR must be observed to trend lower than tropospheric temps over time if one wants to conclude that the operative “greenhouse” warming mechanism has even a potential effect on anything.”

      OLR has to be observed to trend LOWER than tropospheric temps over time, which is distinctly NOT the same as saying one needs to observe an absolute REDUCTION in OLR over time. The OLR simply has to go down RELATIVE TO tropospheric temps.

      And that is exactly what the schematic above is showing. The “greenhouse” warming mechanism allegedly works when Earth’s Ts (and Ttropo) is observed to rise over time while its Te (=> OLR) is observed to stay unchanged (flat) over time.

      If something else (like the Sun) is doing the original warming, however, then we can no longer expect the OLR (Te) to stay flat over time. It will rise. But we WILL still expect to see it rise distinctly LESS over time than the Ts and Ttropo. If we assume that the “greenhouse” mechanism is still working and making a contribution, that is …

      Which takes us back to this one – tropospheric temps vs. OLR at the ToA over the last 32+ years (ERBS+CERES):

      Conclusion: There is no empirical evidence from the real Earth system to suggest that an “enhanced GHE” has been contributing to ‘global warming’. Because everything’s simply and evidently working exactly the way it should be, without a theoretical “radiative forcing” imposed on the system from a gradual rise in the atmospheric level of IR opacity.

      In fact, we can tell from those same datasets (ERBS Ed3_Rev1 & CERES EBAF Ed4) that the sole cause of our current positive radiative imbalance at the ToA is an INCREASE IN THE SOLAR HEAT INPUT and that Earth’s heat output to space (the OLR at the ToA) has rather slightly countered this by simply increasing in step with the temperatures.

      IOW, the causal chain looks like this:
      +ASR => +T => +OLR

      • Norman says:

        Kristian

        When I look at the graphs the CERES team has developed for the globe I do not see the type of graphs you are drawing. I see basically a flat-line that is expected. The Out going LWR will not help you determine if the surface is hot or cold.

        I was looking at these graphs on this site.

        https://ceres-tool.larc.nasa.gov/ord-tool/jsp/EBAFSelection.jsp

        Just don’t look like yours.

        • okulaer says:

          Norman, CERES only goes back to 2000. Here’s CERES EBAF Ed4 (newest version, officially released in February this year, IIRC) gl ToA OLR vs. UAHv6.0 gl TLT and gl TMT:

          Tropospheric temps haven’t gone up since 2000. They basically fluctuate around a flat trendline. If there were an “enhanced GHE” in operation, then in such a situation we would expect to see the OLR sloping distinctly down over the same period. But we don’t. What we see is how it simply tracks Ttropo. WITHOUT an “enhanced GHE”, that’s exactly what we’d expect. WITH an “enhanced GHE”, however, that is exactly NOT what we’d expect.

          The ERBS data, directly preceding CERES, runs from 1985 to 1999, and it is clearly seen to follow Ttropo up over the period. No systematic reduction in OLR relative to tropospheric temps over time here either:

          When you combine the two records and compare them to the TLT data, you get my original plot. The calibration across the 5 month data gap between the two (1999-2000) was done by careful and direct alignment with the ISCCP FD and HIRS datasets, both of which span the gap:

  3. Norman says:

    One of your Mars surface temperature links is dead at this time.

    I am not sure I would bank a whole conclusion on some Martian studies of surface temperature as it seems a complex task. One should not just look at the data that supports their conclusions

    Here is one book analysis of Mars temperature.
    https://books.google.com/books?id=stFpBgAAQBAJ&pg=PA81&lpg=PA81&dq=mars+observed+surface+temperature&source=bl&ots=4eXF5f1_Ff&sig=QslC5Q6_uqiVPuhkenU7hHY5tH0&hl=en&sa=X&ved=0ahUKEwjthe_4m6rTAhVm9IMKHd17A_I4ChDoAQgyMAM#v=onepage&q=mars%20observed%20surface%20temperature&f=false

    Or this
    http://marsnews.com/the-planet-mars

    • okulaer says:

      Norman, you say:

      I am not sure I would bank a whole conclusion on some Martian studies of surface temperature as it seems a complex task. One should not just look at the data that supports their conclusions

      I’m not sure you understand what we’re talking about here. What do you think I’ve been doing? I have specifically looked through the various sources on the subject. However, whenever I see the standard +5 to +8 K Martian GHE claim, I naturally try to look behind it. I don’t just automatically take it as gospel truth. I wonder, how did they arrive at that figure? I want to see exactly what they BASE this claim on. What empirical data? What consistent, globally averaged multiyear measurements? Invariably there are none. It is just stated. Clearly simply a GUESS based on the idea that there somehow MUST be a small GHE on Mars because there is so much CO2 in its atmosphere. And that’s it. It has become a self-sufficing factoid. But it is obviously a specious claim and nothing else.

      Take a closer look at your two links and what they say. The first one claims the average surface temperature of Mars to be 215 K (Table 4.2). We’ve heard that one before. But it offers NO relevant empirical data to support that figure. It just states it. No way for the reader to test its validity. However, already in the next table (4.3) we see a number that should give us pause. The global average surface temperature of THE MOON is claimed to be … 277 K, 7 K higher (!!!) than its calculated blackbody temperature in space (Te). Now in what universe is that physically possible!? I call bullshit.

      Your second source can’t even agree with itself – over just a couple of paragraphs – what the average surface temperature of Mars really is. First it says: “But Mars is a cold planet now; the average recorded temperature on Mars is -63° C (-81° F) with a maximum temperature of 20° C (68° F) and a minimum of -140° C (-220° F).” Then, a wee bit later it states the following: “While the average temperature on Mars is about 218° K (-55° C, -67° F), Martian surface temperatures range widely from as little as 140° K (-133° C, -207° F) at the winter pole to almost 300° K (27° C, 80° F) on the dayside during summer.” OK? So tell me, what IS the “average temperature on Mars”? Is it -63 or -55 degrees C? Or is it simply … something else altogether?

      You see the silliness here, Norman?

      Well, so what do you do if you want to find out for yourself what is really the case?

      You go look for data. Actual relevant data. You don’t look for single site data. You don’t look for tropical data. You don’t look for seasonal data. You look for consistently measured GLOBAL, FULL-YEAR data, preferably spanning multiple years. So where do you go? You go to the SATELLITES. The two papers I linked to compared different Mars-monitoring satellite datasets, three in all:

      # IRTM (InfraRed Thermal Mapper; Viking),
      # TES (Thermal Emission Spectrometer; MGS (Mars Global Surveyor)), and
      # MCS (Mars Climate Sounder; MRO (Mars Reconnaissance Orbiter)).

      The three overlap and basically cover the period from the 90s till today.

      Fenton et al., 2007:
      http://depts.washington.edu/marsweb/papers/PDFs/Fenton-etal-2007-warming-albedo-changes.pdf

      Bandfield et al., 2013:
      http://gemelli.spacescience.org/jbandfield/publications/bandfield_mcs_tes.pdf

      And what they find is an average global Martian surface temperature that is 7-9 K lower than the planet’s Te in space (~211 K).

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