Why do we need global pix?

Chapman & Ferraro [1932] wanted the neutral plasma from the sun to produce a "ring current" as it envoloped the Earth. This current was needed to explain Dst. But they didn't know how.
Alfven tried electric fields [1952?] and failed.
Finally Fred Singer [1957] realized that dipoles trap charged particles which carry a current via the grad-B drift.

Chapman & Ferraro [1932] wanted the neutral plasma from the sun to produce a "ring current" as it envoloped the Earth. This current was needed to explain Dst. But they didn't know how.