The IUGONET Project The upper atmosphere is considered a
compound system consisting of the mesosphere, thermosphere,
ionosphere, and magnetosphere. Although the different
atmospheric layers are often referred to as independent regions,
they are closely coupled by exchange of materials, momenta, and
energies through complicated physical processes, for example, -
Energy input from the sun, e.g., ultraviolet radiation and the
solar wind, drive convection of both neutral and charged
particles; - Momenta and energies from the stratosphere and
troposphere are injected by atmospheric waves; and - Many
internal phenomena (e.g., electromagnetic energy transport,
plasma convection, chemical reaction) exist. Therefore, what we
observe is the result of such complicated processes. To
investigate the mechanism of long-term variations in the upper
atmosphere, we need to create integrated and organic links
between a variety of ground-based observations made at various
locations from the equator to the poles. However, the dat