Recent content by Tandem78

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    GISS surface temperature - confidence intervals

    The HadCRUT4 global surface temperature anomalies in tabular form include confidence intervals. The GISS surface temperature data is available in tabular text form here http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt - but it doesn't include any confidence intervals. Can...
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    Stuve diagrams, dry and wet adiabats

    Steve, Andre, thanks for your replies, but maybe I'm not explaining my question clearly enough. I am trying to understand how the explanation of the Stuve diagram tallies with real weather. I am supposed to take the temperature and RH and plot a dry adiabat up to the condensation level where...
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    Stuve diagrams, dry and wet adiabats

    I understand the idea that an unsaturated parcel of air will rise along the dry adiabat until the condensation level is reached, at which point the air is saturated with moisture. If it rises further, it will do so along the moist adiabat - but doesn't that mean at the same time that water...
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    Why does CO2 keep keep heat within the atmosphere? (on the molecular level)

    CptWayne wrote: I don't quite understand how this statement can be reconciled with the equipartition principle. Surely the energy in the vibrational modes should distribute into the translational modes? And once this happens, the translational modes should distribute among other molecules by...
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    Could a Splatnik be the solution to space debris?

    The braking effect works preferentially on smaller and lighter objects. A fleck of paint 2mm across might weigh a few milligrams. An object as large as a satellite weighing maybe 500kg would be unaffected. The paint fleck has a mass to area ratio of the order of 1 Kg/m2, whereas the satellite...
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    Could a Splatnik be the solution to space debris?

    Some of you may have heard of the study just published by the NAS of the prospects of dealing with space junk - follow http://www.scientificamerican.com/article.cfm?id=orbital-debris-space-fence for the story and links. Most of the hazardous debris consists of extremely small particles...
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    Is the Planet's Surface Hotter Than Its Shell?

    That is what I thought too. Thanks.
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    Is the Planet's Surface Hotter Than Its Shell?

    The context is a dispute as to whether the temperature gradient of an atmosphere is the inevitable consequence of the increasing pressure with depth, or whether a source of energy is required.
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    Is the Planet's Surface Hotter Than Its Shell?

    well, not quite... imagine an earth-like planet totally enclosed in a shell of some material which conducts heat and has near black-body properties both inside and out. The shell is at a distance of some 100s of kilometres from the planet's surface. The shell is light enough so that it has no...
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    Gas radiation question - He, H2 vs O2, N2

    Yes, this is not the same as emission of photons due to changes in electron orbits or vibrational states, it's about how an atom or molecule can convert its thermal (ie kinetic) energy into electromagnetic energy, even when it carries no charge. You say that thermal radiation is universal...
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    Why does CO2 keep keep heat within the atmosphere? (on the molecular level)

    It's because of the Lapse Rate. The Lapse Rate is the temperature gradient in the troposphere, and is determined by the combination of (mainly) convective and (partially) radiative heat transfer. However, this only determines the temperature gradient and not the absolute temperature - you need...
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    Gas radiation question - He, H2 vs O2, N2

    You're right - I'm thinking of ions like in chemistry, duh... So is the ionization the key to the answer?
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    Gas radiation question - He, H2 vs O2, N2

    The explanation I saw in a lecture was that when one of the vibrational modes of a complex molecule (H2O, CO2, CH4 etc) is excited, this creates an asymmetry in the structure, and this creates an asymmetry in electric charge - in other words a dipole. This is not the case for diatomic...
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    Gas radiation question - He, H2 vs O2, N2

    Hey, that might be the explanation - at least ions have an electric charge. So an ion moving with thermal energy can interact with the electromagnetic field and convert the thermal (kinetic) energy into radiation. Not a very good formulation, but does that makes sense? T. PS thinking...
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    Gas radiation question - He, H2 vs O2, N2

    A question has been bothering me for some time - when we look at the sun, what are we looking at? The standard answer is - the photosphere. The sun consists mostly of hydrogen and helium, and that the radiation from the photosphere is approximately a black body continuum spectrum at 6000K...
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