Accession Number : AD0686238

Title :   A PRELIMINARY STUDY OF THE INSTABILITY AND DEVELOPMENT OF ULTRA-LONG WAVES,

Corporate Author : EMMANUEL COLL BOSTON MASS ORIENTAL SCIENCE RESEARCH LIBRARY

Personal Author(s) : Yeh Tu-Cheng, ; Wang Hsiao-Ling,

Report Date : MAR 1969

Pagination or Media Count : 34

Abstract : The instability and development of ultra-long waves under frictionless and adiabatic conditions are discussed. The vertical distribution of the static stability and the vertical wind shear of the basic current are found to be factors controlling the instability of ultra-long waves. The occurrence of instability requires that the environmental static stability increases with height and this condition is fulfilled in the atmosphere by virtue of the existence of the stratosphere. The greater the magnitude of the vertical wind shear, the higher is the degree of instability of these waves. Equations relating the vertical wind shear of the basic current to the variation of static stability are derived on the assumption that the disturbances exert a 'feedback' effect on the basic current. This effect is much more pronounced on vertical wind shear than static stability. In addition to the vertical wind shear of the basic current and the vertical distribution of static stability, the wavelength also affects the development of ultra-long waves though this parameter does not affect the maximum amplitude of the mature disturbance. However, the longer the wavelength, the longer it takes for the disturbance to fully develop. The presence of the stratosphere tends to reduce the amplitude of mature disturbances at low levels and enhance those at high levels. (Author)

Descriptors :   (*METEOROLOGICAL PHENOMENA, *UPPER ATMOSPHERE), STRATOSPHERE, WIND, SHEAR STRESSES, ATMOSPHERIC MOTION, STABILITY, INTENSITY, WEATHER FORECASTING, MATHEMATICAL PREDICTION, CHINA

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE