Development of an Experimental Geophysical Fluid Dynamics Laboratory

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EAR-0236799AurnouThis proposal requests funds to develop essential instrumentation for a new experimental fluid dynamics laboratory in the Department of Earth and Space Sciences at UCLA. Using state-of-the-art techniques, experiments will provide detailed characterizations of flow dynamics at nearly planetary parameter values and will provide quantitative measurements of the flow fields that are believed to be critical components of the geodynamo. The quantitative results will test several long-held, but unproven, tenets regarding the dynamics of convection occurring in the deep Earth. The proposed instrumentation will utilize the recently developed technique of acoustic Doppler velocimetry to study convection in liquid metals that have material properties similar to that of the Earth's iron-rich outer core. The Doppler system will quantify convective velocities in a thermally-driven, large volume, plane layer rotating magnetoconvection tank. This set-up has the advantage of attaining an Elsasser number, the ratio of magnetic and rotational forces, that is close to one, as is estimated for the geodynamo. Quantitative measurements, including thermometry and Hall probe magnetometry in addition to velocimetry, will test accepted theories about how the Elsasser number may control convection in the core. This new instrumentation will provide a powerful, new platform for generating quantitative data relevant to the deep Earth and the geodynamo.***