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Auroral Kilometric Radiation and Earth Hum Sounds

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  • Dexter McIntyre W4DEX
    Auroral Kilometric Radiation Earth Hum Sounds:
    Message 1 of 5 , Jul 2 7:54 AM
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    • Gallagher, Dennis L. (MSFC-VP62)
      Neat they did a bit on auroral kilometric radiation (AKR). They made it sound like this is new and that we haven t already long measured similar emissions at
      Message 2 of 5 , Jul 2 8:14 AM
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        Neat they did a bit on auroral kilometric radiation (AKR). They made it
        sound like this is new and that we haven't already long measured similar
        emissions at all the magnetized planets, however, which is not the case.
        Decametric radiation at Jupiter and Saturnian Kilometric Radiation at
        Saturn are produced by the same physical process that produces AKR. The
        AKR emission has 10^7 Watts of power on average and 100 times that
        during active conditions in the frequency range roughly from 50kHz to
        500kHz, peaking at about 200kHz. The sounds they play on this web site
        are downshifted to audio from a satellite electric field radio receiver
        operating in a wideband mode. It's good they mention about how
        extra-solar planets might be found using radio reception at relatively
        low frequencies. Any magnetized planet in the presence of a solar wind
        will likely produce these emissions, with the strength of the planet's
        magnetic field determining the frequency range of the emission.

        Dennis

        ________________________________

        From: VLF_Group@yahoogroups.com [mailto:VLF_Group@yahoogroups.com] On
        Behalf Of Dexter McIntyre W4DEX
        Sent: Wednesday, July 02, 2008 9:55 AM
        To: VLF
        Subject: [VLF_Group] Auroral Kilometric Radiation and Earth Hum Sounds



        <http://geo.yahoo.com/serv?s=97359714/grpId=4518040/grpspId=1707581616/m
        sgId=9307/stime=1215010502/nc1=3848614/nc2=4507179/nc3=5286666>



        [Non-text portions of this message have been removed]
      • Ernst D. Schmitter
        Dennis, does it make sense then to monitor noise around 200kHz and relate its intensity to geomagnetic activity ? Best regards, Ernst
        Message 3 of 5 , Jul 2 11:50 PM
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          Dennis,

          does it make sense then to monitor 'noise' around 200kHz and relate
          its intensity to geomagnetic activity ?

          Best regards, Ernst
        • Gallagher, Dennis L. (MSFC-VP62)
          Ernst, Unfortunately not. AKR is entirely reflected away into space by higher densities below the emission region and closer to the Earth. Radio JOVE is a NASA
          Message 4 of 5 , Jul 3 6:44 AM
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            Ernst,

            Unfortunately not. AKR is entirely reflected away into space by higher
            densities below the emission region and closer to the Earth. Radio JOVE
            is a NASA project to encourage listening to Jovian decametric radiation
            from the ground however. Jupiter's magnetic field strength is some 30
            times stronger than Earth's with the result that the emission frequency
            is high enough to get through the Earth's ionosphere. At earth the
            emission seems to fill a broad cone centered around auroral magnetic
            field lines and pointed outward. The cone is created by refraction of
            AKR by higher densities at lower altitudes. At Jupiter the emission at
            distance away from the planet more resembles the properties of the
            emission itself, which is an annulus centered at close to 90 degrees
            from the field line direction, otherwise something like a hollow
            emission cone. The consequence is that we see Jupiter like a lighthouse
            light that is phased with its moon Io. Whenever Io and Jupiter are at
            equal distance from the Earth the emission sweeps over the earth with
            Io's orbital motion.

            Dennis

            ________________________________

            From: VLF_Group@yahoogroups.com [mailto:VLF_Group@yahoogroups.com] On
            Behalf Of Ernst D. Schmitter
            Sent: Thursday, July 03, 2008 1:50 AM
            To: VLF_Group@yahoogroups.com
            Subject: [VLF_Group] Re: Auroral Kilometric Radiation and Earth Hum
            Sounds



            Dennis,

            does it make sense then to monitor 'noise' around 200kHz and relate
            its intensity to geomagnetic activity ?

            Best regards, Ernst






            [Non-text portions of this message have been removed]
          • Ernst D. Schmitter
            Dennis, thanks for the explanation, Ernst
            Message 5 of 5 , Jul 3 7:24 AM
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              Dennis,

              thanks for the explanation, Ernst
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