incluye referencia bibliográfica (páginas 43-44)

The structure of the thermosphere and ionosphere are particularly interesting along the
longitude sector containing South America and the Antarctic Peninsula due to the unique geometry
of the geomagnetic field. For these locations, solar associated effects are probably well separated
from geomagnetic effects. Modeling of the Thermosphere-Ionosphere-Plasmasphere system has
shown that the relation between thermospheric circulation, vertical motions, and composition
changes has specific characteristics in this longitude sector. Moreover, the ionospheric phenomena
related to tropospheric forcing such as atmospheric gravity waves, are also of significant interest,
since the Antarctic Peninsula may be considered as an effective barrier to the prevailing and strong
westerly winds, being almost perpendicular to the barrier. To better assess some of the above
indicated characteristics and phenomena, a latitudinal extension of available ionospheric
observations for many years at Argentine Islands (65°S, 64°W), Port Stanley (52°S, 58°W) and
Halley Bay (76°S, 27°W) was needed. Thus an ionospheric station was installed and operated at
King George Island (62°S, 59°W), and the present report makes the corresponding data base
obtained, available to the scientific community at large. Detailed instructions are given to access the
hourly (at 15 min intervals for a few cases) and monthly mean values for the 1986-1991 interval.
Also, a routine is provided on request to plot diurnal variations of critical frequencies and virtual
heights for the ionospheric E- and F-regions.