Abstract. Magnetosheath jets are regions of high dynamic pressure, which can traverse
from the bow shock towards the magnetopause. Recent modelling efforts, limited
to a single jet and a single set of upstream conditions, have provided the
first estimations about how the jet parameters behave as a function of
position within the magnetosheath. Here we expand the earlier results by
doing the first statistical investigation of the jet dimensions and
parameters as a function of their lifetime within the magnetosheath. To verify
the simulation behaviour, we first identify jets from Magnetosphere
Multiscale (MMS) spacecraft data (6142 in total) and confirm the Vlasiator
jet general behaviour using statistics of 924 simulated individual jets. We
find that the jets in the simulation are in quantitative agreement with the
observations, confirming earlier findings related to jets using Vlasiator. The
jet density, dynamic pressure, and magnetic field intensity show a sharp jump
at the bow shock, which decreases towards the magnetopause. The jets appear
compressive and cooler than the magnetosheath at the bow shock, while during
their propagation towards the magnetopause they thermalise. Further, the shape
of the jets flatten as they progress through the magnetosheath. They are able
to maintain their flow velocity and direction within the magnetosheath flow,
and they end up preferentially to the side of the magnetosheath behind the
quasi-parallel shock. Finally, we find that Vlasiator jets during low solar
wind Alfvén Mach number MA are shorter in duration, smaller in their extent, and
weaker in terms of dynamic pressure and magnetic field intensity as compared
to the jets during high MA.