Propagation of Acoustic - Gravity Waves in the Atmosphere

]Komogeneous wave guide theory is used to derive dispersion curves, vertical pressure distributions, and synthetic baregrams for atmospheric waves. A complicated mode structure is found involving both gravity and acoustic waves. Various models of the atmosphere are studied to explore seasonal and geographic effects on pulse propagation. The influence of different zones in the atmosphere on the character of the baregrams is studied. It is found that the first arriving waves are controlled by the properties of the lower atmospheric channel. Comparison of theoretical results and experimental data from large thermonuclear explosions is made in the time an,d frequency domains, and the following conclusions are reached: (1) The major features on baregrams are due to dispersion; (2) superposition of severM modes is needed to explain observed features; (3) scatter of d•t• outside the range permitted by extreme atmospheric models shows the influence of winds for Ax; wind effects and higher modes are less important for A• waves. A discussion is included on atmospheric terminations and how these affect dispersion curves.