摘要:
选取1982/1983年夏季(6~8月)欧洲中期预报中心850hPa、300hPa两层纬向风场的网格点资料,采用复经验正交函数(CEOF)讨论了准双周振荡的位相传播及振荡的地理特征。结果表明:①20°N以南对流层高层(300hPa)1982年振荡显著区域是印度半岛至菲律宾东部一个西西北—东东南走向的带状区域;低层(850hPa)1982年5°~15°N之间以及中国东南部及其沿海地区都是振荡的显著区域;而1983年30°N以南振荡明显比1982年弱,只有中国东南沿海部分地区及孟加拉湾东南、马来西亚北部是振荡的显著区域。②对流层高层(300hPa)1982年85°~90°E,30°~40°N的青藏高原是振荡的源区,其南传支波列可传到孟加拉湾北部的20°N附近;而1983年青藏高原上80°~90°E,35°~40°N区域是振荡的汇区。
Abstract:
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