Climate Models Miss Effects of Wind-Shattered Dust

Discussion in 'Environment' started by daveman, Dec 30, 2010.

  1. daveman
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    daveman Diamond Member

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    Climate Models Miss Effects of Wind-Shattered Dust
    Clumps of dust in the desert shatter like glass on a kitchen floor. This similarity may mean the atmosphere carries more large dust particles than climate models assume.

    Dust and other airborne particles’ effect in the atmosphere is “one of the most important problems we need to solve in order to provide better predictions of climate,” said climate scientist Jasper Kok of the National Center for Atmospheric Research in Boulder, Colorado. Other researchers suspect current models also neglect a large fraction of the climate-warming dust that clogs the skies after dust storms.

    Most climate models use dust data from satellites that measure how many particles of different sizes are suspended in the atmosphere. These measurements reveal an abundance of tiny clay particles roughly 2 micrometers across (about one-third the width of a red blood cell), which can reflect sunlight back into space and cool the planet.

    But satellites may be missing larger particles, called silts, which don’t hang around in the air as long. Silts up to 20 micrometers in diameter can act as a warm blanket to trap heat inside the Earth’s atmosphere.

    --

    Kok’s theory suggests that dust storms produce two to eight times more silt-sized particles than climatologists previously thought. Neglecting the boost in particles suggests that climate models, and even short-term weather models for dusty regions, are somewhat off. Until climate scientists better understand how dust changes over time, however, Kok said it’s tough to gauge the effects.​

    Anyone pointing to the models as "proof" of AGW needs to realize how imperfect the models are...simply because what they're modeling is far more complex than we know. Maybe than we can know.
     
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  2. Old Rocks
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    Old Rocks Diamond Member

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    Well, yes, the models are presently primative, and we don't know all of the factors. Yet, the results that we are seeing indicate that the warming is progressing much faster than predicted for just the GHGs by themselves. And, when the warming and changes in atmospheric circulation increase desertification in some areas, then you could well say that the silt effects that you are talking about is a feedback from the present warming.
     
  3. Revere
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    The only science offered is that if you're taxed on your energy until you have to go on welfare to afford energy, things might change in a few hundred years.
     
  4. Matthew
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    Matthew Blue dog all the way!

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    More heat near the surface of the earth remains and dont have the ability to go to space. Increasing night time temperature more and more....On venus you cant see the sun to good through those massive clouds and atmosphere. But is 900f!
     
    Last edited: Dec 30, 2010
  5. Mr. H.
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    Jasper Kok?
     
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    Yeah, the temperature on all the planets is changing.
     
  7. Old Rocks
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    A scaling theory for the size distribution of emitted dust aerosols suggests climate models underestimate the size of the global dust cycle ? PNAS

    models underestimate the size of the global dust cycle
    Jasper F. Kok1
    + Author Affiliations

    Advanced Study Program, National Center for Atmospheric Research, Boulder, CO 80307
    Edited by Inez Y. Fung, University of California, Berkeley, CA, and approved October 27, 2010 (received for review October 4, 2010)

    Abstract
    Mineral dust aerosols impact Earth’s radiation budget through interactions with clouds, ecosystems, and radiation, which constitutes a substantial uncertainty in understanding past and predicting future climate changes. One of the causes of this large uncertainty is that the size distribution of emitted dust aerosols is poorly understood. The present study shows that regional and global circulation models (GCMs) overestimate the emitted fraction of clay aerosols (< 2 &#956;m diameter) by a factor of &#8764;2–8 relative to measurements. This discrepancy is resolved by deriving a simple theoretical expression of the emitted dust size distribution that is in excellent agreement with measurements. This expression is based on the physics of the scale-invariant fragmentation of brittle materials, which is shown to be applicable to dust emission. Because clay aerosols produce a strong radiative cooling, the overestimation of the clay fraction causes GCMs to also overestimate the radiative cooling of a given quantity of emitted dust. On local and regional scales, this affects the magnitude and possibly the sign of the dust radiative forcing, with implications for numerical weather forecasting and regional climate predictions in dusty regions. On a global scale, the dust cycle in most GCMs is tuned to match radiative measurements, such that the overestimation of the radiative cooling of a given quantity of emitted dust has likely caused GCMs to underestimate the global dust emission rate. This implies that the deposition flux of dust and its fertilizing effects on ecosystems may be substantially larger than thought
     
  8. Old Rocks
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    Well yes, some declining, others increasing.
     
  9. Matthew
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    Matthew Blue dog all the way!

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    So more of the kind that causes heat to remain within our Atmosphere and cause more warming.:eusa_drool:
     
  10. Mad Scientist
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    Mad Scientist Deplorable Gold Supporting Member Supporting Member

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    Well gosh darn it! We better give all our money to the government and go live in caves.

    That'll solve everything! (herpa derp!) :uhoh3:
     

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