  The nature of Ohm's law is examined in a turbulent flow of liquid sodium. A
magnetic field is applied to the flowing sodium, and the resulting magnetic
field is measured. The mean velocity field of the sodium is also measured in an
identical-scale water model of the experiment. These two fields are used to
determine the terms in Ohm's law, indicating the presence of currents driven by
a turbulent electromotive force. These currents result in a diamagnetic effect,
generating magnetic field in opposition to the dominant fields of the
experiment. The magnitude of the fluctuation-driven magnetic field is
comparable to that of the field induced by the sodium's mean flow.
