Ionospheric Wind Systems and Electron Concentrations of the F Layer

Viscosity in theFregion

“…This has important consequences for the F region. Viscosity need not prevent a general circulation in the F region, whose existence was previously suggested by Yerg [4]. If such a ckrculation were driven by heating lower in the atmosphere, however, it could be treated as a thermal tide, and Wilkes [5] has shown that tidal motions are heavily attenuated even below the F region.…”

Circulation in the upper atmosphere

“…From the distribution of zonal winds in the 80 to 100 km region discussed above, the meridional motions due to the effect of viscosity are inferred. These meridional motions reach ..their maximum value at about 200 km, where the kinematic viscosity reaches its maximum [Yerg, 1951]. From considerations of continuity, it is reasonable to expect that the return meridional flow will occur above 200 km and below 300 km.…”