11:00 AM - 11:15 AM
[PEM15-07] Magnetosphere-ionosphere-thermosphere-middle atmosphere coupling in the polar region
Keywords:thermosphere, ionosphere, middle atmosphere, aurora, magnetosphere
and lower atmosphere have been shown from observations and numerical simulations. In
particular, it is known that some meteorological phenomena would have impacts on
the thermosphere and ionosphere; for example, typhoon and sudden stratospheric warming
events. The coupling between neutrals and plasmas is wellknown and important processes
to understand various ionospheric and thermospheric variations. When we understand
all the coupling processes between the regions, we would come close to realizing the
predictions of the ionospheric and thermospheric weathers.
In the present study, we focus our attention on the polar ionosphere and thermosphere
where various coupling processes would exist. Among the coupling processes, chemical
ones caused by the precipitating particles in the polar region seem to be far from
complete understandings for us. We have made observations of the dayside polar cap
ionosphere using the EISCAT radar system to monitor ionospheric disturbances due to
the particle and energy inputs from the magnetosphere. The polar cap ionospheric
disturbances in the higher latitude have been observed at almost all the time even
during geomagnetically quiet periods. We will show some fundamental features of the
polar cap ionosphere revealed from the EISCAT observations. In addition, we have
performed modelling studies to understand physics and chemistry of the polar ionosphere
and thermosphere. In the present study, we will introduce our attempt to estimate productions
of ions, NOx, and HOx in the altitude of 50-500 km due to precipitating particles.
The results from the EISCAT observations and modelling studies will be included
in our whole atmosphere and ionosphere GCM, GAIA, in the future.