Authors: Carson Brown (University of Delaware), Bennett Maruca (University of Delaware), B. Alterman (NASA Goddard), Riddhi Bandyopadhyay (University of Delaware), Ramiz Qudsi

The solar wind experiences substantial heating and acceleration as it expands through interplanetary space. One way of quantifying this expansion is examining how the average values of plasma parameters (e.g. temperature or magnetic field strength) vary with radial distance from the Sun. The Trans-Heliospheric Survey is a compilation of in-situ observations of the solar wind from 13 different spacecraft with the aim of better understanding these “radial trends.” This study analyzes the observed trends in proton speed and temperature using the Parker (1960) polytropic model, finding excellent agreement between observed v_p values and the model. The v_p measurements are further statistically separated via their speed type revealing distinct radial trends in the fast and slow solar wind.