Summary of the hourly solar wind speed, Alfvén speed, and Alfvén Mach number measured by PSP from E04 to E20. Intervals containing sub-Alfvénic solar wind are highlighted in magenta. Left: Quantities displayed as a function of PSP’s radial distance. PSP’s inbound journey is on the left, the outbound journey on the right. Structure in the radial scans is quickly discerned in this view, but the longitudinal scans are compressed. Right: Quantities shown as a function of PSP’s Carrington longitude. The radial scans are obscured, but the structure in each longitudinal scan is easily distinguished.