Overview of the selected ultrafast solar wind event observed by PSP. (a) Spacecraft location during the selected interval. (b)–(d) Radial, tangential, and normal components of the magnetic field and solar wind velocity. (e) Plasma number density and proton temperatures parallel and perpendicular to the background magnetic field. (f)–(g) One-dimensional power spectra of the electric and magnetic fields. A pronounced spectral enhancement in the 1–10 Hz range indicates the presence of intense ion-scale fluctuations.