Research on Linear and Nonlinear Atmospheric Waves.

Abstract

Abstract : In this report we review the results of a three-year study of linear and nonlinear waves in the atmosphere based on an experimental program at the Warramunga Seismic Station located at 19 deg. 56 min S near Tennant Creek in the Northern Territory of Australia. The first section of the report provides a brief description of the installation of the infrasonic arrays, the acoustic sounding system, the array-associated meteorological instrumentation, the data acquisition system and the digital time series analysis techniques. The second section outlines the basic studies of four separate classes of atmospheric wave phenomena. First, a description is given of the discovery of three fundamentally different types of atmospheric solitary wave. Secondly, the results and implications of a study of the evolutionary properties of a new form of soliton-generating propagating disturbance in the lower troposphere are presented. The third investigation is concerned with a study of the characteristics of acoustic microbarom radiation in the Southern Hemisphere with regard to a determination of the equatorial structure of the stratosphere and lower thermosphere. Finally, an outline is given of the research into the origin of nonlinear long-period irregular atmospheric gravity waves. In the appendices of this report we present two separate papers which detail the studies of solitary atmospheric waves and soliton-generating intrusive disturbances. (Author)