Production of auroral zone E region irregularities by powerful HF heating

Production of ionospheric 1‐m irregularities in the auroral zone E region by high power ionospheric heating has been observed by means of the STARE auroral radar. Irregularities were produced at night, on eight occasions by using an O mode heating wave and on two occasions by using an X mode heating wave. The growth time of the irregularities is found to be approximately 30 s. Several physical possibilities to explain these findings are discussed, and a mechanism is suggested that is closely related to Sato's mechanism of quiet auroral arc formation.