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Apparent numerical instability?


New member
Hi there,

The figures below show the W velocity component in my model output at ground level, and at vertical level 40 (a height of around 2,400 m). The variations in W which seem reasonable at ground level (following terrain) result in a checkerboard type pattern at higher altitude.

Any suggestions of model options which might help with this? My time step is 10s in my outer domain with 18km resolution. My nested domain is 2km resolution with a time step ratio of 6. I'm not seeing any CFL warnings. I am using epssm=0.5, and w_damping=1.

I have attached my namelist.input file for further detail.

Thanks in advance



  • namelist.input
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