First observations of summer polar mesospheric backscatter with a 224 MHz radar



Exceptionally strong echoes from the mesopause region have been observed with the EISCAT 224 MHz radar during the summer of 1987. The echoes are so strong that they cannot be explained by incoherent scatter theory but may instead be associated with neutral air turbulence. We discuss the variability of these echoes in terms of time and height distribution, and outline some characteristics of vertical velocity oscillations observed at the echo height.