摘要
文中探讨了中尺度地形背风驻波及对天气系统发生发展的影响问题，通过建立一个含类似大别山地形作用的简化数学模型并进行了数值计算，结果表明，当过山气流u取１０１ｍ／ｓ量级，层结参数Ｎ取１０(－３)ｓ(－１)量级，其比值Ｕ／Ｎ约为３×１０３～４×１０３时可出现一种相当正压的地形背风波，其波长近于Ｕ／ｆ～１０２ｋｍ（ｆ为柯氏参数）。结合上述理论结果和实际暴雨个例，分析指出在江淮梅雨期间，当有移动性的暴雨区移至大别山定常背风波的适当位置时，暴雨会得到增幅。
In this paper. the influence of meso-scale stationary lee wave on the genesis and development of synoptic system is discussed. A simplified mathematical model including the roleof Dabieshan is established for numerical calculation, the result indicates: when basic flow Uequals to 101 m/s, stratification parameter N equals to 10-'3s-1 and the ratio of U to N approximates 3 X 103~4 X 103, a kind of equivalent - barotropic lee wave could appear. its wavelength approximates U/f (f is Coriolis parameter- 10--4s-1 ). Then a practical case of heavyrain is analysed by using above conclusion to point out during Jianghuai meiyu pened. whenmigarating rainstorm moves to certain position of Dabieshan's stationary lee wave, the precipitation could intensify.
出处
《气象学报》
CSCD
北大核心
1999年第6期705-714,共10页
Acta Meteorologica Sinica
基金
国家自然科学基金
关键词
中尺度
地形背风波
相当正压
雨团
增幅
Meso-scale lee wave
Equivalent barotropy
Rainstorm
Intensification.
