Results from the plasma experiments on Aeros

The two plasma experiments aboard the Aeros-B satellite determined the main plasma quantities in the height range 220-880 km. These complementary instruments, a retarding potential analyser and an impedance probe, provided the electron and ion temperatures, the main ion constituents, the suprathermal electron flux and the plasma density. This paper summarizes a selection of the obtained results. Comparisons of several quantities with other observations demonstrate the high reliability of the Aeros plasma data. As a contribution to sensor theory a dependence of RPA measurements on the magnetic field vector has been established. The ion temperature and composition turn out to undergo a strong latitudinal variation, the highest hydrogen concentration in the upper atmosphere being located at + or - 20 deg latitude.