The influence of high speed plasma streams on the ionospheric plasma

As shown by statistical investigations, high speed plasma streams (HSPS) in the solar wind cause direct ionospheric effects in the D- and Es-layers at auroral and subauroral latitudes due to increasing precipitation of high energetic particles as well as indirect effects in the F2-region at high, middle and equatorial latitudes caused by auroral heating processes. The ionospheric effects increase with the strength of the HSPS and are most pronounced for HSPS during IMF pro sectors (sectors with negative B_z-component). Seasonal differences of the ionospheric response to solar velocity changes are caused by the IMF influence (maximum effect at equinoxes) as well as internal atmospheric reasons (enhanced variability during winter).