Abstract:
The purpose of this paper is to discuss the nature
of the electrical field induced in the ocean by
particular types of velocity distribution. It is
believed that these examples will be helpful in the
interpretation of measurements by towed electrodes
in the sea.
The electrical field induced by waves and tidal
streams, originally predicted by Faraday (1832),
was first measured experimentally by Young,
Gerrard and Jevons (1920), who used both
moored and towed electrodes in their observations.
Recently, the technique of towed electrodes has
been developed by von Arx (1950, 1951) and
others into a useful means of detecting water
movements in the deep ocean. While the method
has been increasingly used, the problem of interpreting
the measurements in terms of water movements
has become of great importance. Two of the
present authors have made theoretical studies
(Longuet-Higgins 1949, Stommel 1948) dealing
with certain cases of velocity fields, and Malkus
and Stern (1952) have proved some important
integral theorems. There seems, however, to be a
need for a more extended discussion of the principles
underlying the method, and for the computation
of additional illustrative examples. This is
all the more desirable since some of the theoretical
discussions published previously have been misleading.
