Determination of F-region Vertical Drifts at Millstone Hill


  • J. V. Evans,

  • R. A. Brockelman,

  • R. F. Julian,

  • W. A. Reid,

  • L. A. Carpenter


Thomson scatter observations of the F region at altitudes between 450 and 900 km are described; from them the bulk vertical velocity of the ambient electrons can be determined. These measurements were made possible by the construction of a new spectrum analyzer; they supplement earlier established programs to measure F-region densities and temperatures at Millstone Hill. The uncertainty in the results varies both with time of day and with altitude but is of the order of ±5 m/sec. Sample results are presented which show evidence of (1) thermal expansion and contraction of the layer and (2) oscillatory fluctuations attributed to traveling ionospheric disturbances.