At this website, we present recent model results that illustrate the thermal,
compositional and dynamical
responses of these upper atmospheres to solar EUV-UV flux variability
making use of the Earth TIEGCM, the Mars MTGCM, and the Venus VTGCM
three-dimensional models. Each of these models has been developed and exercised
at the National Center for Atmospheric Research using its CRAY computers.
The motivation of this research is not only to simulate the observed
responses of these individual planets to solar EUV-UV flux variations, but
also to understand the relative importance of common processes that regulate
this unique behavior. For instance, the role of O-CO2 enchanced 15-micron
cooling (thermostatic effect) is investigated in the context of
global dynamics and its effect on atomic-O distributions. In addition, the
role of global dynamics in controlling temperature distributions (and their
variations over the solar cycle) is studied. Standard EUV-UV
solar flux datasets are adopted for use in all three thermospheric models.
Specific cases for solar maximum (MAX) (F107=200), solar medium (MED) (F107=130),
and solar minimum (MIN) (F107=68) conditions are conducted.
Corresponding figures for each planet are displayed horizontally (in 3-panels)
so that steady state output fields can be easily compared. In addition,
time dependent (solar flux) runs are also conducted for each planet
in order to monitor the timescales for
equilibration among the changing composition, temperature, and wind fields.
These timescales are clearly a strong function of altitude and therefore
are quite different for each planet as a result of the
feedbacks and thermostats in operation for each. Corresponding time-dependent
figures are again displayed horizontally (in 3 panels) to aid comparison.