  We present a 3D fully selfconsistent multi-fluid hydrodynamic aeronomy model
to study the structure of a hydrogen dominated expanding upper atmosphere
around the hot Jupiter HD 209458b and the warm Neptune GJ 436b. In comparison
to previous studies with 1D and 2D models, the present work finds such 3D
features as zonal flows in upper atmosphere reaching up to 1 km/s, the tilting
of the planetary outflow by Coriolis force by up to 45 degrees and its
compression around equatorial plane by tidal forces. We also investigated in
details the influence of Helium (He) on the structure of the thermosphere. It
is found that by decrease of the barometric scale-height, the He presence in
the atmosphere strongly affects the H2 dissociation front and the temperature
maximum.
