Coordinated observations of the mesopause region with radar and optical techniques

This paper reports the development of coordinated observations carried out with the use of the MU radar (middle and upper atmosphere radar) and optical measurement techniques in Shigaraki. Since the start of the MU radar operation, mesosphere wind and turbulence were studied using mesospheric turbulence echo in the daytime. More recently, meteor echoes have been used to observe wind and temperature around the mesopause, during day and night. Comparative observations with the MU radar meteor mode and sodium lidars were used to study gravity waves and variation of sodium layers. Airglow observations were also carried out as a campaign basis, with which small scale and large scale gravity waves have been studied. We have also developed two CCD imagers to observe airglow images at the MU radar site for long term observations with the radar. Now Shigaraki has become an integrated optical/radar site ready to contribute to the PSMOS (Planetary Scale Mesopause Observing System) project being carried out between 1998–2002.