LARGE-SCALE, PERSISTENT LATITUDE STRUCTURES IN THE MESOSPHERIC TEMPERATURE DURING ANLC-93

Michelson interferometer measurements of the hydroxyl (OH) Meinel night-airglow emissions were made from the NCAR aircraft during the ANLC-93 Campaign. The spectra have been analysed to give the OH band radiance and rotational temperature, which is taken to be the neutral temperature at the peak of the OH emissions near 87 km. On two occasions, once in the presence of Noctilucent Clouds (NLC), the research flights spanned similar to 10 degrees of latitude and reached as high as 66 degrees N. The mean latitudinal structure of the measured mesospheric temperature field is in good agreement with the CIRA-86 model. In addition, both measurements show large-amplitude (similar to 15K), large-scale (2-4 degrees of latitude), quasi-periodic oscillations about the model mean. Finally, the data support the hypothesis that these oscillations are temporally stable, and that they, along with the air mass characterized by the mean temperature field, can be advected with the tidal winds, and play a role in NLC formation.