Calculated and Measured HF/VHF Absorption for the 2-5 November 1969 Solar Proton Event

Electromagnetic wave absorption was measured at several frequencies as a function of altitude for six rocket flights during the 2 to 5 November 1969 Solar Proton Event (SPE). Meaningful data were obtained at 36 MHz, 18 Mhz, and 9 MHz for four of these flights. These data and 30 MHz riometer data are shown to be in excellent accord with the calculated absorption. The agreement provides further support for the accuracy claimed for the electron concentrations that were measured simultaneously by means of dispersive phase techniques. It is stressed that uncertainties in the pressure are probably the largest error source. The electromagnetic wave absorption apparently was uneffected by the SPE-disturbed D-region except for the enhanced electron concentration. (Author).