Development of an Experimental Geophysical Fluid Dynamics Laboratory

本提案要求拨款为加州大学洛杉矶分校地球与空间科学系的一个新的实验流体动力学实验室开发必要的仪器。利用最先进的技术，实验将提供接近行星参数值的流动动力学的详细特征，并将提供流场的定量测量，这些流场被认为是地球发电机的关键组成部分。定量结果将测试几个长期持有但未经证实的关于地球深处对流动力学的原则。提议的仪器将利用最近开发的声学多普勒测速技术来研究液体金属中的对流，这些金属的材料特性与地球富含铁的外核相似。多普勒系统将量化热驱动、大体积、平面层旋转磁对流槽中的对流速度。这种设置的优点是获得埃尔萨塞尔数，磁力和旋转力的比率，接近于1，正如地球发电机估计的那样。定量测量，包括温度测量和霍尔探针磁强计以及速度测量，将测试关于Elsasser数如何控制核心对流的公认理论。这种新的仪器将为生成与地球深部和地球动力学相关的定量数据提供一个强大的新平台

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.***