A comparison between solar X-ray emission and VLF sudden phase anomalies

Very low frequency (VLF) sudden phase anomaly (SPA) data obtained during 1963 are presented for comparison with solar X-ray emission measurements made by VELA satellites during the same period. From the SPA data an estimate is made, for each of three flares, of the effective wavelength of monochromatic X rays that would have produced the same VLF phase effects as the actual X-ray emission. In addition, using the X-ray intensity (flux density) measurements of the satellite data and the wavelength functions obtained from the SPA data, estimates are made of the effective recombination coefficients. Furthermore, it is indicated that the VLF phase anomaly produced by X rays from a high altitude nuclear explosion can possibly be distinguished from that produced by X rays from a solar flare.