  Two questions about the solar magnetic field might be answered together once
their connection is identified. The first is important for large scale dynamo
theory: what prevents the magnetic backreaction forces from shutting down the
dynamo cycle? The second question is: what determines the handedness of twist
and writhe in magnetized coronal ejecta? Magnetic helicity conservation is
important for answering both questions. Conservation implies that dynamo
generation of large scale writhed structures is accompanied by the oppositely
signed twist along these structures. The latter is associated with the
backreaction force. We suggest that coronal mass ejections (CME's)
simultaneously liberate small scale twist and large scale writhe of opposite
sign, helping to prevent the cycle from quenching and enabling a net magnetic
flux change in each hemisphere. Observations and helicity spectrum measurements
from a simulation of a rising flux ribbon support this idea. We show a new
pictorial of dynamo flux generation that includes the backreaction and magnetic
helicity conservation by characterizing the field as a 2-D ribbon rather than a
1-D line.
