Maps of ƒ0F2 derived from observations and theoretical data


  • Charles M. Rush,

  • Margo PoKempner,

  • David N. Anderson,

  • Jane Perry,

  • Frank G. Stewart,

  • Rita Reasoner


Observations of the F2 region critical frequency, ƒ0F2, and values determined from the time-dependent continuity equation for ions and electrons in the ionosphere have been used to develop a new set of numerical coefficients to represent the global variation of ƒ0F2. Like those in earlier investigations, the new coefficients permit monthly median hourly values of ƒ0F2 to be obtained at any location around the globe for any month of the year and solar activity level. Comparisons between ƒ0F2 determined using older sets of numerical coefficients and ƒ0F2 determined using the new set of coefficients are given along with a description of how well each set of coefficients specifies and predicts the observed variations in the F2 region critical frequency.