Orbit in Heliographic Coordinates
ENLIL simulation
Normalized solar wind density at the ecliptic and the IMF lines
Radial solar wind velocity at the ecliptic on the global and detail regions together with the temporal profile at spacecraft

PSP Observation Overvall

PSP observation

PSP observation

ACE observation

ACE observation (continued)

Perrone et al. (2019)

The radial dependence of the proton number density, \(n_p\) and magnetic field magnitude, \(B\), is given by

\[n_p = (2.4 ± 0.1)(R/R_0)^{−(1.96±0.07)} cm^{−3}\] \[B = (5.7 ± 0.2)(R/R_0)^{−(1.59±0.06)} nT\]

The faster decrease of the magnetic than kinetic pressure is reflected in the radial proton plasma beta variation

\[β_p = P_k/P_B = (0.55 ± 0.04)(R/R_0)^{(0.4±0.1)}.\]

References

Perrone, Denise, D Stansby, T S Horbury, and L Matteini. 2019. “Radial Evolution of the Solar Wind in Pure High-Speed Streams: HELIOS Revised Observations.” Monthly Notices of the Royal Astronomical Society 483 (3): 3730–37. https://doi.org/10.1093/mnras/sty3348.