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Physical Sciences: Circular Polarization of Twilight

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Abstract

LINEAR polarization of clear daytime sky and twilight is produced by molecular (Rayleigh) scattering and aerosol (Mie) scattering, which predominates in the infrared. Incident linearly polarized light scattered by aerosols is in general elliptically polarized, whereas no ellipticity can arise from the molecular component1. The principal component of clear daytime sky arises from single scattering of unpolarized sunlight and is not elliptically polarized. However, whenever multiple scattering by the aerosol component is important, the strong linear polarization produced on the first scattering will lead to elliptical polarization from the second and subsequent scatterings. Although in the daytime sky this mechanism should give only a small ellipticity2 (10−5–10−3) the possibility of a substantially larger effect at twilight arises because there is no direct illumination. We report here observations of circular polarization of twilight of order 10−3.

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References

  1. Van de Hulst, H. C., Light Scattering by Small Particles (Wiley, 1957).

  2. Hansen, J. E., J. Atmos. Sci., 28, 15 (1971).

    Google Scholar 

  3. Angel, J. R. P., and Landstreet, J. D., Astrophys. J. Lett., 162, L61 (1970).

    Article  ADS  Google Scholar 

  4. Landstreet, J. D., and Angel, J. R. P., Astrophys. J. (in the press).

  5. Hansen, J. E., Feasibility of Monitoring Particulate Air Pollution from Satellites, Draft Report for UN (1972).

    Google Scholar 

  6. Rosenberg, G. V., Izv. Akad. Nauk SSR Fiz. Atmos. Okeana, 3, 400 (1967).

    Google Scholar 

  7. Eiden, R., App. Opt., 5, 569 (1966).

    Article  ADS  CAS  Google Scholar 

  8. Kemp, J. C., Wolstencroft, R. D., and Swedlund, J. B., Nature, 232, 165 (1971).

    Article  ADS  CAS  Google Scholar 

  9. Gehrels, T., Astrophys. J. Lett., 173, L23 (1972).

    Article  ADS  CAS  Google Scholar 

  10. Martin, P. G., Mon. Not. Roy. Astron. Soc. (in the press).

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Authors and Affiliations

  1. Columbia Astrophysics Laboratory, Columbia University, New York, New York, 10027

    J. R. P. ANGEL & R. ILLING

  2. Institute of Theoretical Astronomy, University of Cambridge, Cambridge

    P. G. MARTIN

Authors
  1. J. R. P. ANGEL
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  2. R. ILLING
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  3. P. G. MARTIN
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ANGEL, J., ILLING, R. & MARTIN, P. Physical Sciences: Circular Polarization of Twilight. Nature 238, 389–390 (1972). https://doi.org/10.1038/238389a0

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  • DOI: https://doi.org/10.1038/238389a0

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