Atmospheric ionization by protons of integral intensity above a cutoff of 0.86 GV at Sanae is too small to record a riometer absorption above noise even during the large ground-level enhancements (GLEs) of September 29 and October 19 and 24, 1989. However, linear increases may be depicted in the absorptions of 20-, 30-, and 51.4-MHz cosmic radio noise that ranged from 0.25 dB per hour at 30 MHz for a GLE with a rising phase of 26% per hour to 0.81 dB per hour for a GLE of 360% per hour. Lowering of cutoff rigidity by magnetospheric ring currents to give direct access to solar flare protons of rigidity below 0.86 GV or precipitation of energetic magnetospheric electrons due to magnetic activity may be ruled out. Mutual consistency appears between the rates in ground-level solar proton enhancements and the rates of increases in absorptions at all three of the frequencies for all three events. This suggests that nonrelativistic solar protons should have traversed the geomagnetic field lines to be precipitated at Sanae. This traversal may be due to equatorward gradient and curvature drifts from the polar cap region, a westward longitudinal drift along L=4.0, and subsequent precipitation into the atmosphere at Sanae due to the South Atlantic Magnetic Anomaly. Preceding these linear increases, solar flare effects with absorption maxima coincident with the maxima of solar flare X rays and the 2.2-MeV gamma ray line have been observed. The rates of recovery in absorption that are faster than that of the 0.5- to 4-¿ X rays suggest that these absorptions are due to ionization caused by still shorter wavelength electromagnetic radiation. ¿ American Geophysical Union 1993