Latitudinal variations of the height of the maximum of the daytime equatorial ionospheric F2-layer

Conditions for the formation of different types of latitudinal variations of hmF2 near the geomagnetic equator are examined on the basis of vertical-sounding data. These variations are found to have a relative minimum at the equator and two maxima at geomagnetic latitudes of 7-10 deg; the formation of these maxima is connected with different dependences of hmF2 on vertical-drift velocity for midlatitude, low-latitude, and equatorial F2-layers. It is shown that the F2-layer discloses either equatorial or midlatitude features depending on the direction and magnitude of the vertical-drift velocity.