The generation and evolution of internal solitary waves by intrusive gravity currents and river plumes are examined in an axisymmetric geometry by way of theory, experiments and numerical simulations. Full depth lock-release experiments and simulations demonstrate that vertically symmetric intrusions propagating into a two-layer fluid with an interface of finite thickness can launch a mode-2 double humped solitary wave. The wave then surrounds the intrusion head and carries it outwards at a constant speed. The properties of the wave's speed and shape are shown to agree well with a Korteweg-de Vries theory that is derived heuristically on the basis of energy conservation. The numerical code is also adapted to oceanographic scales in an attempt to simulate the interaction between the ocean and a river plume emanating from the mouth of the Columbia River. Despite several approximations, the fundamental dynamics of the wave generation process are captured by the model.
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