The Phase Propagations and Geographical Features of the 10~20 Day Oscillation in Summer 1982/1983

By using CEOF, the phase propagations and geographical features of the 10~20 day low-frequency oscillations have been discussed using the data of daily 850 hPa and 360 hPa ECMWF zonal wind data from June to August, 1982/1983. The results show that (1) On 300hPa, the oscillations have a obvious region, it was to the south of 20°N from India to the east of the Philippines in 1982. On 850 hPa, the obvious regions of oscillation were in 5o~15°N, 75 o ~132.5E, and the southeast coast of China in 1982. However, only the obvious regions of oscillation were in the southeast coast areas of China, in the southeast of the Bay of Bengal, and to the north of Malaysia in 1983. (2) On 300 hPa, a source of the oscillation was in 30°~40°N, 85°~90°E in 1982, and the branch oscillation can propagate south ward to the north of the Bay of Bengal around 28°N. However, oscillations converged in 35°~40°N, 80°~90°E in 1983