Solar Physics

, Volume 148, Issue 1, pp 153–167

Three-dimensional structure of the solar wind: Variation of density with the solar cycle

  • P. K. Manoharan


Interplanetary Scintillation (IPS) measurements obtained from a large number of compact radio sources (nearly 150 sources) distributed over the heliocentric distance range 15–175 solar radii (R(⊙) and heliographic latitude ∼75° N-75° S have been used to study the global three-dimensional density distribution of the solar wind plasma. Contours of constant electron-density fluctuations (ΔNe) in the heliospheric plasma obtained for both the solar minimum and maximum show a strong solar latitude dependence. During low solar activity, the equatorial density-fluctuation value decreases away from the equator towards higher latitudes and is reduced by ∼2.5 times at the poles; the level of turbulence is reduced by a factor of ∼7; the solar-wind mass flux density at the poles is ∼25% lower than the equatorial value. However, during high solar activity, the average distribution of density fluctuations becomes spherically symmetric. In the ecliptic, the variation of ΔNe with the heliocentric distance follows a power law of the formR−2.2 and it does not show any change with solar activity.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • P. K. Manoharan
    • 1
  1. 1.Radio Astronomy CentreTata Institute of Fundamental ResearchUdhagamandalam (Ooty)India

Personalised recommendations