摘要
天气分析,为近年来气象学上最大之收获,气团之分布,与极面之移动既明,则短期预告,自较昔日仅凭经验之法则为准确。惟地面观测常以种种影响而不得明其真相。是故高空测候,因以日见发达。天气之预测,乃由地面之观察,进而为三度之分析。我国测候事业,尚在草创时期。测候所可用者数不满百,高空纪录,尤感缺乏。
At 2pm 16th of March,the cnld Ps(Polar Siberian)air mass was on the way to invade China Proper.The discontinuity as seen by wind direction along the cold front,extended from Inner mongolia to North China.The warm front treuded SW-ward at a distance of about 200km,west of Nanking.The temperature in the warm sector ranged from 15℃.to 20℃.,while that to the east of the front was mostly five to ten degrees lower.As showen by the sounding balloon observation taken at Pei-Chi-Ko in the afternoon of the 16th,the frontal inversion was 3,330m.in height over Nanking,which was nearly the height of A-St.observed by the pilot balloon simultaneously.The layers,from the surface to 2.22km and from 3.05km.to 3.33km.were in conditional instability.But that from 2.22km.to 3.05km.was absolutely stable.The moist and cool Pp(Polar Pacific)air mass below the frontal inversion seems to be NPs(transformed Polar Siberian),which returned from the relatively warm ocean as a SW-ly or SE-ly current.Above this inversion,the tropical air mass was ia a state of absolute stability which was probably due to the modification during its N-ward journey.This may explain why no preci-pitation was received in the regions to north of the Yangtze during the passage of the frontal systems.On the next morning,the Ps air mass already spread over the whole North China,strong N-ly winds with heavy duststorm prevailed.In most places,tbe temperature fell below or near to OC.and the pre-sure rose 12mm,or even more.The well marked cold front went SE-ward along Wei-Ho and Middle Hwang-Ho then turned NE.and ran along the trough of the V-shaped depression centercd in N.Korea.The warm front over E.Sea extended to Korea and tended to move NE-ward,but its movement was much slower than that of the cold front.The rotation of the frontal systems,was very obvious.In the warm sector on the land,the fog or the drizzle spread over widely.The condition was the worst in The Lower Yangtze.in most places the visible distance was limited to 100m only,and the visibility at Chin-kiang even decreased to zero.This extensive tropical air mass fog was the result of the high absolute humi-dity,the stability of the air mass,the clearnss of the sky in the night,and the small pressure gradient.The adiabatic cooling due to the falling of the pressure was not sigqnificant as observed from the barometric curve of Nanking.It was not until noon,that the coid front arrived in The Yangtze Val-ley.The retardation of its W.section was because of the mountainous topography of W.China,especially The Tibet Plateau and The Tsing-ling Ranges.Heteafter the cold front moved SE-ward and eventually the Ps air mass overwhelmed all China.
出处
《气象学报》
1936年第4期184-194,共11页
Acta Meteorologica Sinica
