Structure and Dynamics of the Quiet Chromosphere

Smithsonian Institution Astrophysical Observatory, Cambridge MA

Investigators

Abstract

This investigation will address the question: Is the quiet solar chromosphere at the top always hot (7000 K), with small temperature variations (5%), or mainly cold (2000 K), with large temperature excursions (up to 25,000 K)? Two kinds of current empirical models, one a set of time-independent models of the steady emission, the other, a time-dependent simulation of the dynamics of the non-magnetic chromosphere, come to fundamentally different conclusions. To gain a resolution of this problem a two-pronged approach will be employed. On the one hand, space observations are to be analyzed to determine the temperature and the amplitude of oscillations in the actual solar chromosphere, and on the other, numerical and analytic tools will be developed for a theoretical assessment of chromospheric heating by magnetohydrodynamic waves.