The objective of this activity is the development of a theoretical and empirical understanding of the ionospheric thermospheric domain in the 100-1000 km altitude region. To accomplish this objective it is proposed to continue SUNDIAL investigations focused on global scale ionospheric physics, its solar and interplanetary controls, and its coupling to the magnetosphere and thermosphere, SUNDIAL investigations merge the accumulated ionospheric, magnetospheric interplanetary and solar inputs, and will use the combined data to test first- principle and empherical models dealing with measurements and " in situ" observations from relevant satellite programs of opportunity through ground based activity. The data and models will be reviewed and analyzed in workshops. Special issue journal publications will be developed. The data base will archived for follow-on investigations and baseline support for efforts to develop a geospace prediction capability. ***
