Dr. Balbus will pursue a number of different theoretical studies involving large scale astrophysical gas dynamics. The investigations involve primarily galactic scale systems, and emphasis is placed on our own Galaxy in most of the projects. The projects have been motivated by observations of ionized gas in the disk and the halo of our Galaxy, as well as by observations of cool gas in the disk of the Galaxy. Theoretical developments in the field of nonlinear dynamics have also been an important stimulus for at least one of the studies. There is little question that the problems of understanding large scale disk structure in our Galaxy are entwined with the dynamical properties of its gaseous interstellar medium (ISM). This is due not only to the well appreciated connection between the ISM and dynamically cold star formation, but also to the belated realization that the highly responsive gas is an important structural component in its own right, whether or not it happens to be making stars. Dr. Balbus' studies generally share a common purpose of developing the connection between local and global gasdynamical processes commonly occurring in the disk and halo of our Galaxy.
