The incoherent scatter radar facility (ISR) recently installed at Sondre Stromfjord, Greenland (inv. lat.=74¿) has been used to investigate events of substantially elevated E-region temperatures related to the occurrence of strong horizontal elecctric fields. It has been found that a peculiar type of weak, slowly fluctuating cosmic noise absorption commonly observed in the daytime on riometers in the polar region could be caused by non-deviative collisional absorption resulting from the strongly enhanced electron-neutral collision frequencies in the heated E-region.