中国中部低层大气行星波无线电探空仪的观测研究

Radiosonde Observation of Planetary Waves in the Lower Atmosphere Over the Center China

通过分析武汉、宜昌和恩施气象局无线电探空仪2001—2003年的观测数据,研究了中国中部地区对流层和低平流层中行星波的特性。通过Lomb-Scargle(L-S)的周期图方法发现了周期为准16天和周期为准10天的谱分量占据着主导地位。观察发现,较大振幅的行星波振荡主要集中在5—15km之间。准16天行星波沿纬圈向西传播,对应的纬圈波数大约为2,水平波长约为17324.8km,传播相速度约为-12.5m·s^(-1)(东向为正),通过计算准16天行星波在10 km以下相位随高度的改变可以得到其垂直波长大约为25—30 km,而在对波层顶附近其相位几乎没有发生改变,呈现出静态波特性。准10天行星波沿纬圈向东传播,对应的纬圈波数大约为4,水平波长约为8627.3 km,传播相速度约为10.0 m·s^(-1),垂直波长约为22—40 km。

Wind data by the radiosonde observation from Wuhan, Yichang, and Enshi Meteorological Stations in the period of 2001-2003 are used to analyze the Planetary Waves （PWs） in the lower atmosphere of the center China. L-S periodgrams show that quasi-16-day PWs and quasi-10-day PWs are dominating planetary wave components in the observed period over three sites. The largeamplitude oscillation of PWs can be observed primarily from 5 km to 15 km. The quasi-16-day PWs propagate westward with a zonal wave number of 2 （the horizontal wave length is 17 324.8 km）, and the corresponding phase velocity is estimated to be -12.5 m·s^-1 （positive eastward）. The vertical wavelength is estimated to be 25-30 km according to the phase variation with height below 10 km. The phases almost keep unchanged around the tropopause which indicates they may be stationary waves. Quasi-10-day PWs propagate eastward with a wave number of 4 （the horizontal wave length is 8627.3 km） and the corresponding phase velocity is estimated to be 10.0 m·s^-1, the vertical wave length is 22-40 km.