Earlier revealed morphological features of the <i>fo</i>F2 and <i>hm</i>F2 long-term trends are interpreted in the scope of the geomagnetic control concept based on the contemporary F2-layer storm mechanisms. The F2-layer parameter trends strongly depend on the long-term varying geomagnetic activity whose effects cannot be removed from the trends using conventional indices of geomagnetic activity. Therefore, any interpretation of the <i>fo</i>F2 and <i>hm</i>F2 trends should consider the geomagnetic effects as an inalienable part of the trend analysis. Periods with negative and positive <i>fo</i>F2 and <i>hm</i>F2 trends correspond to the periods of increasing or decreasing geomagnetic activity with the turning points around 1955, and the end of 1960s and 1980s, where <i>fo</i>F2 and <i>hm</i>F2 trends change their signs. Such variations can be explained by neutral composition, as well as temperature and thermospheric wind changes related to geomagnetic activity variations. In particular, for the period of increasing geomagnetic activity (1965–1991) positive at lower latitudes, but negative at middle and high latitudes, <i>fo</i>F2 trends may be explained by neutral composition and temperature changes, while soft electron precipitation determines nighttime trends at sub-auroral and auroral latitudes. A pronounced dependence of the <i>fo</i>F2 trends on geomagnetic (invariant) latitude and the absence of any latitudinal dependence for the <i>hm</i>F2 trends are due to different dependencies of NmF2 and <i>hm</i>F2 on main aeronomic parameters. All of the revealed latitudinal and diurnal <i>fo</i>F2 and <i>hm</i>F2 trend variations may be explained in the frame-work of contemporary F2-region storm mechanisms. The newly proposed geomagnetic storm concept used to explain F2-layer parameter long-term trends proceeds from a natural origin of the trends rather than an artificial one, related to the thermosphere cooling due to the greenhouse effect. Within this concept, instead of cooling, one should expect the thermosphere heating for the period of increasing geomagnetic activity (1965–1991).<br><br><b>Key words. </b>Ionosphere (ionosphere-atmosphere interactions; ionospheric disturbances)