A convection driven geodynamo model, with a dominantly dipolar field which intermittently reverses polarity, is described. The model employs the two-mode approximation introduced by Jones et al. [Jones, C.A., Longbottom, A.W., Hollerbach, R., 1995. A self-consistent convection driven geodynamo model, using a mean field approximation, Phys. Earth Planet. Int., 92, 119–141]; nevertheless, it exhibits many similarities to the fully three-dimensional models of Glatzmaier and Roberts [Glatzmaier, G.A., Roberts, P.H., 1995b. A three-dimensional convective dynamo solution with rotating and finitely conducting inner core and mantle, Phys. Earth Planet. Int., 91, 63–75; Glatzmaier, G.A., Roberts, P.H., 1996a. An anelastic evolutionary geodynamo simulation driven by compositional and thermal convection, Physica D, 97, 81–94]. The velocity field is dominated by a `thermal wind' structure throughout, with this form of flow favouring the production of an essentially steady dipolar field. A decrease in the meridional circulation of this flow leads to a preference for oscillatory fields. Dynamical fluctuations in this part of the flow may therefore initiate episodes of field reversal, thus constituting a simple kinematic reversal mechanism. This mechanism is consistent with a numerical reversal sequence studied, where intermittent fluctuations in the meridional component of the thermal wind velocity, associated with `buoyancy surges', are observed. Both our solutions and the comparable three-dimensional solutions are dominated by similar axisymmetric fields, suggesting that nonlinear interactions giving rise to higher wavenumbers are here of secondary importance. The magnetic field plays a surprisingly small role in the dynamics, viscosity retaining an important role. The use of hyperdiffusivities, employed as a parameterisation of the small-scale diffusion beyond our resolution, appears to contribute towards both these features. Nevertheless, the essential axisymmetric features of the solution, related to rather simple physical mechanisms, constitute a feasible model for the reversing geodynamo.