During the intense solar particle events of August 3--11, 1972, 28 cases of simultaneous data were obtained between the polar-orbiting satellie 1971-089A and the incoherent scatter radar at Chatanika, Alaska. Effective electron loss rates (&psgr;) in the D region ionosphere have been derived as a function as of altitude, solar zenith angle (&khgr;), and the magnitude of the production rate (Q). Production rate profiles extending from 3¿102 to 3¿104 ion pairs/cm3 s were calculated for the 40- to 90-km region. Electron density profiles extending from 5¿103 to 105 el/cm3 were measured, useful data being obtained down to altitudes as low as 50 km. Values of &psgr; were obtained for daytime and sunrise/sunset conditions over a range of solar zenith angles from 50.4¿ to 98.6. A strong diurnal dependence in &psgr; as observed only at altitudes below 80 km. Twilight values of &psgr; at the lower altitudes were over an order of magnitude larger than the daytime values. Between 70- and 90-km altitude the present polar summer daytime values of &psgr; are significantly larger than those obtained in the winter daytime event of November 2, 1969. Near 80-km altitude the present results are consistent with the dominant ions being the hydrated ions H2O+(amu=19 and H3O+⋅H2O (amu=37). A strong seasonal dependence in the effective loss rates has therefore been established. A pronounced asymmetry in &psgr; and Ne between the sunrise and sunset twilight was measured at altitudes <80 km, the electron density at sunset being larger than at sunrise at the same solar zenith angle. The altitude behavior of &psgr; and the temporal leads and lags measured in the transitions between twilight and day were found to be consistent with the interaction of the solar visible and ultraviolet wavelengths with the ozone layers above the earth, leading to the sunrise increase and sunset decay of O and O2(1Δ). The dependence of &psgr; on the magnitude of the production rate during the day was found to be weak, a slight positive dependence being measured at altitudes <63 km.