The results of a comparative analysis of model computations and experimenta
l data for the main ionospheric trough region based on data of 45 ionospher
ic stations are considered. The set of equations for the high-latitude iono
spheric-thermospheric model and the algorithm for its solution are presente
d. The scheme for parallel computing model equations is given for the first
time. It is shown that the experimental results can be explained by taking
into account the influence of large-scale electric fields on the neutral-w
ind velocity via ion deceleration.