Long–period variations of upper and middle atmosphere parameters from experimental data of Siberian scientific instruments.

Shpynev B.G.1, Oinats A.V.1, Medvedeva I.V.1, Chernigovskaya M.A.1, Belinskaya A.Yu.2
  1. Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia
  2. Geophysical Survey SB RAS, Novosibirsk, Russia

Long-period variations of upper atmosphere parameters were investigated for the matter of their connection
with tidal processes and determination of their many-days periodic changes. Data of ground based optical
instruments, data of the MLS device on board AURA satellite, incoherent scatter data for electron density,
temperature and ion composition at the ionosphere height, as well as GPS total electron content and ionosound
data were used for the analysis. It was found that the most pronounced long-time variations of the upper
atmosphere parameters appeared due to the change of relative phase of solar thermal and lunar gravitational
tides. It was founded that the main variations of upper atmosphere parameters are caused by wave-like pro-
cesses of tidal origin. The greatest effect in the disturbance of the neutral atmosphere parameters is caused
by global planetary waves, described as Rossby planetary waves, moreover tidal processes initiate generation of
new circulation cells, which cyclically recur. Appearing in neutral atmosphere, the long-period disturbances also
exist at ionosphere heights, where they are easily registered by radiophysical and optical methods. According
to experimental data the most significant are the variations with the following periods 14-15, 6-7 and 2-4 days.
The work is financially supported by the Russian Fund for Fundamental Study, grant № 09-05-00757.