摘要
如何获取大气重力波参数是大气动力学理论研究的重点和难点。本文以2013年8月6—8日晋西北地区出现的一次雷阵雨天气过程为例,利用常用的二阶、三阶、四阶曲线拟合和带通滤波方法获取垂直高分辨率探空资料的扰动场,对这些扰动场提取的大气重力波参数进行对比分析。结果表明:不同扰动场(二阶、三阶、四阶曲线拟合以及带通滤波)对所获取重力波参数的大小及变化趋势存在影响,但对不同重力波参数的影响程度不一样。其中,对波固有周期、水平和垂直波长的大小及变化趋势影响很大,而对波传播方向、对地水平群速及固有相速的影响程度则较弱。结合6—8日天气现象的大气动力特征,发现由二阶曲线拟合、带通滤波对应扰动场得到的重力波参数的大小及变化趋势与此吻合,其结果可信度最高;而由四阶曲线拟合扰动场得到重力波参数值的可信度最低。
How to obtain the atmospheric gravity wave parameters is one of the most important topics in atmospheric dynamic theory.By taking a thunder storm process on 6-8 August 2013 in northwest Shanxi province as an example in the paper and by using the commonly used second-order polynomial fitting,third-order polynomial fitring,fourth-order polynomial fitting and Bandpass filtering methods to obtain disturbance fields （denoted as SeOp,ThOp,FoOp and BpFp,respectively） from sounding data with high resolution,the paper conducted comparative analysis on the atmospheric gravity wave parameters obtained from those disturbance fields by using different methods.The results showed that different disturbance fields （second-order curve fitting,third-order curve fitting,fourth-order curve fitting and Bandpass filtering） exerted certain influence on the value and trend of the gravity wave parameters to different degrees.They exerted obvious effect on the value and trend of wave period,horizontal and vertical wavelength while posed little influence on the propagation direction,group velocity and phase velocity.By considering the dynamic characterisitcs of the thunder storm process during 6-8 Ausugst 2013,the gravity wave parameters obtained from SeOp and BpFp showed the highest reliability while the gravity wave parameter obtained from FoOp showed the lowest reliability.
作者
程胡华
CHENG Huhua(The Met Office of Taiyuan Satellite Launch Center,Kelan 036301, China)
出处
《大气科学学报》
CSCD
北大核心
2017年第3期401-411,共11页
Transactions of Atmospheric Sciences
基金
总装青年科技基金项目(2014ZBTY4003)
太原卫星发射中心科学基金项目(2015ZBTY4008)
关键词
重力波参数
曲线拟合
滤波
雷阵雨
探空资料
Gravity wave parameters
polynomial fitting
Bandpass filtering
thunder storm
sounding data
