Modeling of the Atmosphere-Magnetosphere-Ionosphere System (MAMI)


Overview

The interaction between the Earth's atmosphere and our immediate space environment is most obvious at high northern and southern latitudes, where the aurora gives its spectacular displays. Energetic particles from our geospace environment have easy access to the upper atmosphere and cause the light emissions that we see as aurora. The visible aurora is only one phenomenon that the precipitating particles cause. Other effects are an enhanced ionization, temperature changes, compositional changes, enhancement of ionospheric conductivity, and more. These modifications of the ionosphere affect in turn the processes in the magnetosphere. Polarization of ionospheric plasma couples magnetospheric convection to the motion of the neutral atmosphere through ion-neutral collisions. There is a tendency to impose upon the magnetosphere the neutral winds of the upper atmosphere, whether solar driven or as by-products of Joule heating or particle precipitation. Observations have also shown that, at times, the ionosphere becomes a source of plasma for the magnetosphere.

The MAMI investigation focuses on modeling the global, time-dependent response of the thermosphere and ionosphere to magnetospheric sources of energy and momentum carried by particles and fields. The objective it to build as detailed a picture as possible of the effects of the external sources on the terrestrial environment, given the available measurements and in context of the models developed over the past decades. These models are in particular an auroral model AURORA, a data assimilation model AMIE, and a global thermospheric circulation model TIEGCM.


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Last updated: 19 Jan 96
Questions? Comments? Please send E-mail to lumm@gi.alaska.edu