Parker solar probe is providing data from different encounters. If we plot data over a distance (for eg: from 0.5 au to 0.17 au), it shows, towards the sun, interplanetary magnetic field increases. It has also positive correlation with solar wind density and temperature, however, slightly weak correlation was obtained for solar wind speed. I want to learn how solar wind parameters vary over a distance, and a physics associated with it. Need your suggestion (please suggest me some good articles, if available). Thank you.