A two-dimensional nested-grid model of the thermosphere with high resolution in the horizontal direction has been developed to study a number of dynamic, electrodynamic, and chemical problems at high latitudes. The model solves the time-dependent momentum, energy, continuity, and three-constituent composition equation of the neutral gas self-consistently, with the assumption of hydrostatic equilibrium. The grid network consists of a low-resolution height/latitude slice stretching from the equator of one longitude sector, up to the pole, and down to the equator in the opposite sector. Imbedded within this mesh is a system of two nested grids to achieve a latitude resolution of 10 to 20 km. An initial simulation is presented to illustrate the response of the middle and upper neutral thermosphere to a narrow, 1¿ latitude, ''spike'' (100 mV m-1) of electric field in the vicinity of the auroral oval. The simulation revealed a number of points: (1) the magnitude of the dynamic response to the westward ion convection channel was 30% greater than that resulting from an identifical eastward channel purely to the earth's rotation; (2) broadening of the latitudinal extent of the response, particularly on the equatorward edge of the channel, to the narrow primary sources of ion drag and Joule heating was most effected by horizontal advection; (3) horizontal heat conduction was important both within and near the edge of the convection channel; (4) in regions where advection was weak, particularly in the poleward edge of the channel, horizontal viscosity made a significant contribution to a broadening of the response, and viscous dissipation provided an additional heat source.