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Study of aerosols in the atmosphere by twilight scattering

  • G. M. Shah
Article
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Abstract

Photometric measurements of the light scattered from the twilight sky in the direction of the sun’s vertical at an angle of 70° from the zenith, were made during IGY-IGC (1957–59) at Mt. Abu with a photometer the telescope of which covered a circular field of about 1 degree.

Observations showed that there were changes in the slopes of the curves of intensity against the depression θ of the sun below the horizon, when θ was 5–6°. This could be explained by assuming the existence of an aerosol layer at 20–25 km. The height of the layer could however vary from 15 to 30 km.

The lowest heights of the stratospheric aerosol layer at Abu were found to occur in June and the highest in November–December.

A second feebler maximum corresponding to a scattering layer at a height of 45–50 km. was also found on a number of occasions.

Keywords

Dust Layer Aerosol Layer Effective Height Circular Field Screen Height 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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Copyright information

© Indian Academy of Sciences 1969

Authors and Affiliations

  • G. M. Shah
    • 1
  1. 1.Physical Research LaboratoryAhmedabad

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