Liquid Sodium Geodynamo Models

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Lathrop EAR-0207789 This project seeks to better understand the generation mechanism for the Earth's magnetic field. This geophysics grant funds research in a new device designed to self-generate magnetic fields at parameters close to the Earth. This new device drives liquid sodium to flow in a three-meter spherical tank. The tank and the enclosed propellers rotate independently to drive a sodium flow to stretch and amplify magnetic fields. The goal is to better understand the saturation mechanism, which determines the strength of the Earth's field, as well as characterize the dynamics of a saturated self-generating dynamo state (such as reversals). New diagnostics are planned to better characterize the fluctuations in the magnetic field and the fluid velocity, including ultrasound velocimetry, spherical magnetic field sensors, and a magnetic field imaging array. The effects of rotation and Lorentz forces on the velocity and magnetic fields are specific issues these diagnostics will probe. This scientific exploration seeks to shed light on the dynamics of field self-generation on a wide variety of objects showing active fields (the Earth, the Sun, Jupiter, Saturn, Io) as well as those lacking self-generation such as Venus. --