Effects of Rotation on Convective Plumes from Line Segment Sources

Abstract

Abstract Effects of rotation on finite-length line plumes are studied with a three-dimensional nonhydrostatic numerical model. Geophysical convection with this source geometry occurs, for example, as the result of fissure releases of hot hydrothermal fluids at the seafloor from terrestrial release of hot gases and ash during volcanic activity along fissures and in the descent from the sea surface of brines formed during freezing of ice leads at high latitudes. Here the model treats the case of a starting plume of dense fluid descending into a rotating environment. Results are compared with laboratory experiments so that the validity of the model, particularly the nonlinear subgrid-scale mixing formulation, might first be established. Differences in plumes caused by varying rotation rate, &ohm, and buoyancy flux, B0, are the primary focus, with experiments in fluid of depth h spanning a convective Rossby number [B01/3/(2Ωh)] of 0.01−1.0. Rotation initiates spiraling of the descending plumes but it has litt...