The Albedo of Earth

Posted: March 10, 2015 by Andrew in atmosphere, Clouds

image“An important new paper finds that the albedo of Earth is highly regulated, mostly by clouds, with some surprising consequences”.

Origionally posted at Climate Etc

The albedo of Earth

Graeme L. Stephens, Denis O’Brien, Peter J. Webster, Peter Pilewski, Seiji Kato, and Jui-lin Li

Abstract. The fraction of the incoming solar energy scattered by Earth back to space is referred to as the planetary albedo. This reflected energy is a fundamental component of the Earth’s energy balance, and the processes that govern its magnitude, distribution, and variability shape Earth’s climate and climate change. We review our understanding of Earth’s albedo as it has progressed to the current time and provide a global perspective of our understanding of the processes that define it. Joint analyses of surface solar flux data that are a complicated mix of measurements and model calculations with top-of-atmosphere (TOA) flux measurements from current orbiting satellites yield a number of surprising results including (i) the Northern and Southern Hemispheres (NH, SH) reflect the same amount of sunlight within ~ 0.2Wm2. This symmetry is achieved by increased reflection from SH clouds offsetting precisely the greater reflection from the NH land masses. (ii) The albedo of Earth appears to be highly buffered on hemispheric and global scales as highlighted by both the hemispheric symmetry and a remarkably small interannual variability of reflected solar flux (~0.2% of the annual mean flux). We show how clouds provide the necessary degrees of freedom to modulate the Earth’s albedo setting the hemispheric symmetry. We also show that current climate models lack this same degree of hemispheric symmetry and regulation by clouds. The relevance of this hemispheric symmetry to the heat transport across the equator is discussed.

Published in Reviews of Geophysics; [link] to full manuscript.

Excerpts from the Introduction:

There are many reasons why it is important to understand the variability of the Earth’s albedo and the factors that define it:

1. Simple energy balance models of the climate system are unstable to small changes in the amount of energy reflected to space. In these simple models with an albedo overly sensitive to surface temperature, relatively small changes in the absorbed solar energy can swing these models from a near ice-free Earth to a fully ice covered state.

2. It is also speculated that albedo changes potentially regulate the climate system. Lovelock’s Gaia hypothesis, exemplified in the study of “Daisyworld”, suggests that regulation of the system albedo by the adaptation of biota of differing albedos to climate change might in fact buffer the system from the instabilities inherent to earlier energy balance models.

3. The reflection of sunlight by clouds provides an important climate change feedback mechanism. Our inability to quantify these feedbacks with any certainty is recognized as one of the major obstacles in climate change predictions .

4. More locally, the Earths albedo appears to be resilient to other internal changes that might otherwise alter the system albedo. Perturbations to the albedo through effects of aerosol on clouds appears to be buffered by compensating processes that restrict local albedo changes to changing aerosol influences. The implications of these more local compensations to concepts proposed to mitigate climate change through geoengineering cloud albedo are thus profound.

5. Regulation of the Earth’s albedo is also central to other important climate feedbacks, including the snow/ice surface albedo feedback as well as cloud feedbacks.

6. It has also been conjectured that the characteristics of the total energy transport from low to high latitudes are insensitive to the structure and dynamics of the atmosphere-ocean system and are determined primarily by external controls such as the solar constant, the size of the Earth, the tilt of the Earth’s axis, and the hemispheric mean albedo.

We show, as in other studies, that the Northern and Southern Hemispheres (NH and SH) reflect the same amount of sunlight within 0.2Wm2. We show clearly how this is achieved as a consequence of reflection from increased amounts of SH clouds offsetting precisely the increased reflection from the larger NH land masses . The spectral distribution of this reflected energy exhibits clear differences between the hemispheres that reinforce our understanding of how the hemispheric symmetry is established.

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  1. Dai Davies says:

    Further confirmation that Earth, the water planet, has tightly balanced water based thermostat with the major variable influences being solar input and the ease of formation of clouds.

  2. BoyfromTottenham says:

    Hi from Oz. Boom, boom, boom – at least three claimed “pillars” of CAGW blown away – how can it keep standing? Well done, Stephens et al.

  3. AlecM says:

    I have gone down the same path as Lovelock. He would have got where I am now 30 years ago had he not been fooled by Sagan’s incorrect aerosol optical physics. That mistake has also invalidated IPCC climate modelling. Sagan imagined Mie scattering could give 1.0 hemispherical albedo. Visit any NASA cloud website and they claim smaller droplets from more aerosol pollution increase albedo, the relationship between albedo and optical depth being monotonic, asymptoting at 1.0.

    In 2004, NASA buried the work of Twomey, who was on the track of a second optical effect. But this ran counter the Global Dimming then deemed necessary in AR5 to explain the slow down in warming; now they are claiming ‘Missing Heat’. The second optical effect is real. A thundercloud with 0.9 albedo has 80% backscattering from the first few 100 m, the 20% left over is subject to Mie scattering; half goes down, half goes up. In 2010, a researcher in Trenberth’s Department discovered the same as me, this hidden ‘forcing’ as he imagined, but he has apparently not been allowed to publish. The bottom line is that the sign of the Aerosol Indirect Effect is the reverse of that claimed.

    I wrote a paper but it too has been sidelined. The importance is that biofeedback by phytoplankton explains the amplification of Milankovitch tsi increase at the end of ice ages and the real AGW as Asia industrialised; aerosol increase reducing low level cloud albedo until the effect saturated in 1998 or so. It also explains the Arctic melt-freeze cycle. No CO2-AGW is necessary; it is near zero because the water cycle automatically corrects surface radiative imbalance.

    PS remember folks, Climate Alchemists have also for 54 years been taught that Radiant Emittance you measure with a ‘pyrgeometer’, is a real energy flux: it isn’t, being Potential radiant energy flux from the emitter, in a vacuum, to a radiation sink at Absolute Zero’. This is why we engineers solve radiation problems by using the vector sum of irradiances at the plane in question. All Radiative, Cloud and IR physics used in the IPCC Climate Models is wrong. This is our version of Lysenkoism, the radiant emittance mistake being our version of Phlogiston.

  4. Richard111 says:

    I have a few of Lovelock’s books. Enjoyed them all. Sad he was ‘got at’.

  5. hunter says:

    The cliamte obsession still stands for the same reason that eugenics stood long past when it was obviously wrong.

  6. clivebest says:

    Clouds play the same role as the white daisies in Lovelock’s ‘Daisy World’. The black daisies are the GHE of H2O.

    Here is a simple model of ‘Water World’

  7. Dai Davies says:

    Unlike daisies which are passive, water is an active agent forming a phase change heat pump that transports large amounts of energy to the upper troposphere – about 10^22 Joules/y by my rough calculations, so a major factor of ‘missing heat’ proportions.

    The primary net impact of radiative gasses is to cool the air by radiating energy gained by collisions with O2 and N2. In the upper atmosphere they radiate to space. In the lower atmosphere they just shuffle energy about momentarily with no net impact on the water cycle thermostat because they add no extra energy to the system.

    The system must be viewed as perturbations to the operation of the thermostat. The IPCC models are upside-down – fundamentally flawed. They try to have the CO2 tail wagging the water cycle dog.

  8. Alec,
    Please do not blame Carl Sagan for all of this. The destruction of science is more widespread and much more recent. Consider this from the JoNova site. An oft referenced Bible from poor Max.

    “Not according to Dr. Max Planck, a gas always absorbs and radiates EM energy at all frequencies as the gas will radiate at a non-zero intensity at all temperatures and all frequencies.”

    This assumption of a gas as a metal without frequency resonance is the new absurdity, Alec.

    see eqn. 274, p. 198 here:
    This just after eqn (276)
    “This is the specific intensity of a monochromatic plane polarized ray of the wave length λ which is emitted from a black body at the temperature T into a vacuum in a direction perpendicular to the surface.”

    These fools refuse to translate “specific intensity” into the current engineering “specular radiance”, a potential for radiative flux. They specifically ignore “into a vacuum in a direction perpendicular to the surface.” which demands a direction with no opposing “radiance” at any frequency.
    The old guys were careful in their writing, not so much any more!🙂

  9. Dai Davies says:

    I should have said that 10^22 Joules/y is just for thunderstorms. Calculated from some figure for typical storm multiplied by 7 million storms per year – I think satellite imaging.

  10. I think I have said before the whole earth energy budget is nonsense. The figures for heat loss from the surface by evaporation and convection are made up figures to justify a loss by radiation based on an average global surface temperature of 15C (which is nonsense on several points). The so-called long wave “window” is a rounded figure which has been found to be in error. The late Dr Noor Van Andel calculated a figure based on actual Planck distribution and known wavelength absorptivities of gases in the atmosphere and found it to be about 66 W/m2 which was similar to others mentioned in literature. He corresponded with Dr Trenberth who admitted that it was 66 W/m2 (not 40 W/m2 as in his energy budget paper) and admitted that he had done nothing to correct his paper as it was too difficult to go the process of correcting the paper. There for a start is a difference of 26 W/m2 which dwarfs the supposed missing heat of around 1W/m2.
    There is no missing heat, there are only poor ( and incorrect) assumptions and poor calculations from people who do not understand the basics of thermodynamics and heat & mass transfer (because they have no chemical or mechanical engineering qualifications and experience)

  11. In case some do not know Dr Noor Van Andel, he was a well respected Dutch Chemical engineer who was one of the few people in the world to understand Miskolczi. He wrote a paper entitled “Note on Miskolczi theory” published in Energy & Environment No4 2010 (with another paper entitled “Tropical rainstorm Feedback”) which are included here

  12. There is no missing heat, there are only poor ( and incorrect) assumptions and poor calculations from people who do not understand the basics of thermodynamics and heat & mass transfer (because they have no chemical or mechanical engineering qualifications and experience)

    Indeed, the nuevo scientists create problems, engineers fix problems. For the engineers, CAGW is not a problem, time to go play with baby’s momma!

  13. Brett Keane says:

    I have watched the flow of information, here and elsewhere, over the years. The breakthrough seemed to come from the various papers contending that the gas laws rule. I learnt them in the early 60s, and hardly gave them a thought for decades. Except for when pumping up tyres or releasing pressure. Among the proofs were solar system atmospheric measurements.

    These had interesting instances of internal, solar-caused interactions, often generating heat and/or albedo (e.g. ozone, water vapour, sulphur compounds). Albedo changes were a common effect of some of these. What I found intriguing in that, was how they seemed to have little or no significant effect on what I think of as the governing adiabatic energy-dissipation cycle. That is what I was referring to recently in another thread.

    I was led to consider that albedo may be more an effect than a cause; two-way endo-exothermy; unconsidered margins of error in incoming solar heating; lags involving non-gaseous masses, for instance. While we are discussing albedo, I would appreciate comment on how it fits into the larger thermodynamic picture. Brett

  14. […] I was over at TallBlokes and he had one of those “look at this” postings he does. It was about clouds. […]

  15. oldbrew says:

    ‘Our inability to quantify these feedbacks with any certainty is recognized as one of the major obstacles in climate change predictions’

    In which case some people should give up peddling disaster scenarios and get a grip on the truth first.

  16. Blob says:

    More evidence in Harry Huffman’s favor if you ask me. The clouds on venus are there as a feedback to maintain the same temp at the same pressure.

  17. Brett Keane says:

    @Blob at 1:38pm: as Harry writes – “Update March 14, 2012: This analysis is so easy, the result so immediately amazing, and the interpretation just above so obvious to me, yet the opposition to accepting it so universal and so determined, that I was led to unconsciously accept, partially but nevertheless wrongly, the premise of incompetent critics, that my findings were invalid because I had not “corrected for albedo”, or in other words had wrongly assumed the Earth and Venus atmospheres were blackbodies, absorbing all the radiation incident upon them.” For this and other reasons, it seems that albedo is part of a modifying system, while incoming solar infared can provide all the required instantaneous heating. Brett

  18. Brett Keane says:

    And further to the above, we forget that gases, lacking surfaces and having ‘gaps’, don’t have to be affected by all EMF that falls upon them. So, the ‘albedic frequencies’ can do as they please, atmospheres don’t care much. Or so it seems to me….Brett

  19. DD More says:

    Dai – Evaporation from the Surface of the Globe – They peg the total energy for evaporation ocean plus land at 1.26 X 10E24 or 25 pecent of energy in at surface.
    paper here –