Shock disturbances in a thermally conducting solar wind

Piston-driven shock disturbances in a thermally conducting solar wind are studied in the context of a simple phenomenological model which admits self-similar solutions. In contradistinction to the predictions of adiabatic models, a decrease in density and a rise in temperature are found behind the shock. These trends compare favorably with a class of observations-e.g., those of Chao et al. (1972) and Unti et al. (1973). This leads to questions concerning the relevance of the use of the postshock rise or fall of the density to identify piston-driven waves from blast waves. It also raises the possibility of identifying preshock disturbances as thermal precursors.