Using the Digisonde data this paper shows that the small variation in the geomagnetic activity during low solar activity can affect both the parameter of height and the frequency of the intermediate layer (ILs) over the low-latitude Brazilian sector. The most expressive responses of the ILs to geomagnetic activity were observed during the summer when the height of the ILs suffered a significant decrease with the increase of the magnetic activity magnetic in the first hours of the day.

Exospheric Ly-α observations of UVIS/HDAC at CASSINI on its Earth swing-by and TWINS are combined to derive the exospheric H-density profile of the ecliptic dayside between 3–15 R_E. At 10 R_E n_H=35 cm⁻³ is found in the vicinity of the subsolar point for quiet space weather conditions. Also a faster radial fall of the dayside H density above 8 R_E (r⁻³) compared to lower distances of 3–7 R_E (r^−2.37) is found and possibly indicates enhanced loss of H atoms near the magnetopause and beyond.

Despite the solar wind being turbulent in nature, numerical models of its interaction with obstacles have until now assumed it to be laminar. The code \textit{Menura} allows for the global simulation of the interaction between a fully turbulent solar wind and various bodies of the solar system. The code is illustrated by a first example: the interaction between a turbulent solar wind and a comet.

We report that the ionospheric plasma flow patterns associated with the J-shaped transpolar arc (a type of nightside distorted TPA), detected by the SuperDARN radar, reveal the formation process of the nightside distortion of a TPA. Equatorward flows at the TPA growth point were observed flowing out of the polar cap and then turning toward the pre-midnight main auroral oval along the TPA nightside distortion. These ionospheric flow patterns would cause the distortion at the TPA nightside end.