Observation and Modeling of the Solar Wind Turbulence Evolution in the Sub-Mercury Inner Heliosphere

Abstract This letter exploits the radial alignment between Parker Solar Probe and BepiColombo in late 2022 February, when both spacecraft were within Mercury’s orbit. allows study of turbulent evolution, namely, change spectral intermittency properties, same plasma parcel during its expansion from 0.11 to 0.33 au, a still unexplored region. The observational analysis solar wind features at two different evolution stages is complemented by theoretical description based on turbulence transport model equations for nearly incompressible magnetohydrodynamics. results provide strong evidence that already undergoes significant distances less than 0.3 au Sun, which can be satisfactorily explained as due evolving slab fluctuations. work represents step forward understanding processes control transition weak properly modeling heliosphere.