Separation of the zonal and meridional components of the neutral wind fromthe hmF2 longitudinal variations

A technique for the separation of both neutral wind components from longitu dinal variations in the F2-layer maximum has been elaborated. The technique is based on an expansion of the vertical plasma drift velocity (m less tha n or equal to 3), geomagnetic field parameters (m less than or equal to 2), and wind velocity (m less than or equal to 1) into the finite Fourier seri es and on a solution of the set of linear algebraic equations for unknown c oefficients of the Fourier series. The technique has been tested, using dat a on topside sounding on board the Intercosmos-19 satellite obtained for fi xed invariant and geographic latitudes of 40 degrees in both hemispheres. I t has been shown that the Tikhonov method for regularization yields the clo sest results to the observations and wind model (HWM). The obtained results make it possible to determine the contribution of different factors to lon gitudinal variations in the F2-layer maximum and to more comprehensively un derstand the causes of the asymmetry of the Northern and Southern hemispher es in the midlatitude ionosphere.