In split-step methods, the contribution of tropospheric scintillation on the propagating electric field is taken into account by modifying the phase of the signal. The extended-LES method has been proposed to generate phase screens that precisely model atmospheric turbulence. It consists in extending the 3D refractive index fields obtained for the large scales of the medium resolved from atmospheric large eddy simulations (LES) to subrange scales following the K41 theory. In this article, we investigate the impact of the vertical LES resolution on an X-band 2D propagation case. To do so, the extended-LES method is tested in a BOMEX Marine Boundary Layer numerically generated for 3 different vertical meshes. Finally, a log-amplitude variance comparison tends to show that propagation results are dependent on the vertical LES resolution at 10 GHz.