  We have developed a variational data assimilation technique for the Sun using
a toy {\alpha}{\Omega} dynamo model. The purpose of this work is to apply
modern data assimilation techniques to solar data using a physically based
model. This work represents the first step toward a complete variational model
of solar magnetism. We derive the adjoint {\alpha}{\Omega} dynamo code and use
a minimization procedure to invert the spatial dependence of key physical
ingredients of the model. We find that the variational technique is very
powerful and leads to encouraging results that will be applied to a more
realistic model of the solar dynamo. We also note that the continuous adjoint
mean-field induction equation is derived in the appendix.
