LONG-PERIOD LARGE-SCALE OSCILLATIONS OF TEMPERATURE DURING THE DYANA CAMPAIGN

During the DYANA campaign (January-March 1990) vertical temperature pr ofiles were measured in the middle atmosphere above 11 rocket and four lidar stations in the northern hemisphere. Strong analysis was applie d, and most oscillations were found to be quasi-periodic only, and res tricted to certain altitude levels. Soley the longest periods (> 4 wee ks) and the shortest periods (around 5 days) were consistently observe d in the whole altitude regime, and were, therefore, further analysed. These temperature variations were found to be compatible with the ass umption that the Quasi-Stationary Planetary Wave No. 1 (QSW 1) of the CIRA 1990 Model Atmosphere was modulated with the respective periods. Especially close similarity of the vertical phase structures was obtai ned. The amplitudes measured were, however, much larger than those of the model, and hence some amendment to the model may be appropriate. T he importance of QSW 1 modulation appears to be considerable, as more than 50% of the temperature variance could be ascribed to it. The DYAN A results were checked by an analysis of respective data from two othe r campaigns (Winter Anomaly campaign, 1976, and MAP/WINE campaign, 198 4). Essentially the same results were obtained. Considering the streng th of QSW 1 control, the midwinter middle atmosphere shows itself to b e quite strongly and persistently structured in both the vertical and horizontal directions. This applies to all parts of the stratosphere a nd mesosphere.