This article presents the results of a study of the energetic electron precipitation as well as important parameters of the D region over Ottawa (45¿N, 76¿W) during lightly to moderately disturbed conditions, using data for the period following the December 17, 1971, magnetic storm as well as data obtained on other selected days exhibiting anomalous D region absorption. Following the December 17, 1971, storm, significant fluxes of precipitating electrons of >130 keV were observed near Ottawa, even during the poststorm period on December 20, when the geomagnetic activity had subsided (&Sgr; Kp=6). The excess ionization detected at D region altitudes above Ottawa can be explained as being due to ionization from a prolonged electron drizzle from the outer radiation belt. For the first time it has been proven that precipitating electrons from the radiation belt were the main cause of D region poststorm conditions of middle latitudes. The ground-based radio probing measurements of the free electron concentration have been coordinated with simultaneous satellite observations of the quasi-trapped and precipitating electron environment above the site. From the ground-based measurements, by using the partial reflection technique at two frequencies (2.66 and 6.275 MHz), electron concentration profiles for altitudes between ?60 and 90 km have been derived at times when the low-altitude polar-orbiting satellite 1971-089 A passed near Ottawa. On board this satellite, electron differential fluxes in 260 channels and at two pitch angles were measured at energies between ?1 and ?2800 keV. The ion pair production rate height profiles due to precipitating electrons were computed for D region heights by using nonisotropic energy-dependent pitch angle distributions. Effective electron loss rates were deduced for heights between 63 and 91 km. These results indicate a significant variability in loss rates in the altitude range 75--85 km.