NASA admits it hasn’t been accurately measuring Earth’s radiation balance

Posted: August 9, 2017 by tallbloke in radiative theory, satellites

ravan_cubesat

In order to measure Earth’s radiation balance, accurate measurements of both incoming and outgoing radiation have to be made. NASA has been testing a new prototype satellite to measure outgoing radiation from Earth. Up until now, the error on this measurement is estimated to be around +/- 5Wm^2, which means any ‘global warming’ signal is lost in the error margin. This has meant scientists have had to rely on models for estimates.

“We know that outgoing radiation from Earth varies widely over time depending on variables such as clouds or aerosols or temperature changes,” Swartz said. “A constellation can provide a global, 24/7 coverage that would improve these measurements.”

“This successful technology demonstration realizes the potential of a new observation scenario to get at a very difficult measurement using constellation missions,” said Charles Norton, program area associate for the Earth Science Technology Office (ESTO) at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Of course, the other side of this equation is measurement of incoming solar radiation, which has been fraught with troubles of its own.

ACRIM letter

Full story

Comments
  1. […] Ref.: https://tallbloke.wordpress.com/2017/08/09/nasa-admits-it-hasnt-been-accurately-measuring-earths-rad… […]

  2. They seem to have done a really good job on TSI though. The latest value from 2008 is 1360,8W. Am I really the first one to ser what that is in T⁴?
    24000000000!!!
    Now plug that into TSI(T⁴)/(4/3), or any of the other equations for the sphere. Rhen think about what toilet we should flush g, watt, joule and kelvin into. It seems like we have a solar system unikt for power. Can be probably be used for anything. Details can be found on my blog.

    I’m really glad all these goodies were left behind for me to pick up, it was a lot of fun. But WTF has been going on in science. Is this a prank or what?

  3. myteurastaja says:

    […] Posted: August 9, 2017 by tallbloke in radiative theory, satellites 3 […]

  4. oldbrew says:

    “We know that outgoing radiation from Earth varies widely over time depending on variables such as clouds or aerosols or temperature changes,” Swartz said.
    – – –
    And oceans.

    ‘ It is with high confidence that ocean warming accounts for 90% of the energy accumulation from global warming between 1971 and 2010.’
    http://en.wikipedia.org/wiki/Ocean_heat_content

  5. tallbloke says:

    And since longwave back radiation from the sky can’t penetrate the oceans to heat them, it looks like it was the drop in low cloud cover as measured by the ISCCP from 1980-1998 that was responsible for the warming doesn’t it?

  6. And the drop in cloud cover was a result of more zonal jet stream tracks during the period of warming.

  7. DB says:

    Hansen et al. looked at the energy imbalance in this 2011 paper:
    http://www.atmos-chem-phys.net/11/13421/2011/acp-11-13421-2011.pdf

    The Hansen paper includes something I found rather amazing:

    “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-yr-mean imbalance of 6.5 W m-2. Because this result is implausible, instrumentation calibration factors were introduced to reduce the imbalance to the imbalance suggested by climate models, 0.85 W m-2.”

    So we really don’t know the TOA (top of the atmosphere) imbalance — we have put in a fudge factor so the measurements agree with models.

  8. Bitter&twisted says:

    So this discrepancy meant that another data “adjustment” was performed, to make the data match the model output.

    Back in my neck of the woods, such a procedure is described as “@rse about face”.

  9. Jim says:

    There, as other climate equations that have been published, all show error rates larger then instrument readings. One would think those instruments were the best available. That the brains used to create those instruments, were the best available. Apparently, not.

  10. oldbrew says:

    ISCCP’s ‘Cloud Climatology: Computer Climate Models’ says [date unknown]:

    When contemporary models are given information about Earth’s present condition — the size, shape and topography of the continents; the composition of the atmosphere; the amount of sunlight striking the globe — they create artificial climates that mathematically resemble the real one: their temperatures and winds are accurate to within about 5%, but their clouds and rainfall are only accurate to within about 25-35%. Such models can also accurately forecast the temperatures and winds of the weather many days ahead when given information about current conditions.

    Unfortunately, such a margin of error is much too large for making a reliable forecast about climate changes, such as the global warming will result from increasing abundances of greenhouse gases in the atmosphere. A doubling in atmospheric carbon dioxide (CO2), predicted to take place in the next 50 to 100 years, is expected to change the radiation balance at the surface by only about 2 percent. Yet according to current climate models, such a small change could raise global mean surface temperatures by between 2-5°C (4-9°F), with potentially dramatic consequences. If a 2 percent change is that important, then a climate model to be useful must be accurate to something like 0.25%. Thus today’s models must be improved by about a hundredfold in accuracy, a very challenging task. To develop a much better understanding of clouds, radiation and precipitation, as well as many other climate processes, we need much better observations. [bold added]

    http://isccp.giss.nasa.gov/role.html#COMP_MODS

    ISCCP = International Satellite Cloud Climatology Project

  11. tallbloke says:

    Jim,
    They are the best available instruments, just not enough of them to get a reliable global reading. The quality of the brains which have been interpreting the data is another issue. I mean, we’re talking about Kevin ‘travesty’ Trenberth here…

  12. 4TimesAYear says:

    Reblogged this on 4timesayear's Blog.

  13. Kip Hansen says:

    Bloke ==> I’d like to see a link to the source of the Richard C. Wilson letter to Scarfetta, something hopefully with a bit of backgrounding context….

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