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Simulation becoming unstable along inflow boundary

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Hello all,

I am trying to replicate an idealized simulation of a QLCS (WRFv4.2.2) that was originally run using the CM1 model. I place a cold air perturbation along the western boundary of the experiment domain to simulate a cold front that moves east with time. Lateral boundary conditions are radiative in the east-west directions and periodic in the north-south directions. While the simulation remains stable during the first 1 - 2 hours, noisy structures eventually develop along the western inflow boundary and become strong enough to make the experiment unstable. We've tried running several experiments to identify the cause of this problem. The wind structures that form along the western boundary do not appear to be attributed to atmospheric instability since they form in the cold air perturbation. We also tried running an experiment with increased atmospheric stability in the boundary layer but the simulation still crashed. The only way we prevented the noisy structures from developing was by employing radiative boundary conditions along all four boundaries of the domain. Has anyone seen a similar problem happen before? If so, do you have any ideas of how to correct this problem?


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We never did such experiments before. At present we have no suggestions how to make this case successful. I have forwarded your post to our expert. If there is any feedback, I I will let you know.