Robert Edmonds
EF5
So, since the fall, a little project of mine is to figure out from the ground up how to build a mesoscale model. After many failed attempts, I finally can report success. The model I have built is a 2D, non-hydrostatic, fully compressible model, which includes water vapor.
The key, at least for me, is that a mesoscale model needs to built around some assumed stable condition. This inhibits a sort of gravity wave that would be produced due to the fact of finite resolution. While there are still a few kinks and unknowns, the model remains stable for several hours. Another key is that computational diffusion is required, but the amount of computational diffusion which is needed is still somewhat unknown. Too little it goes hay wire, too much it goes hay wire. So, I have built the model with the amount of computational diffusion that I can select.
Below is a run from the model, starting with an area of higher potential temperate. Within this region I have also included some water vapor. There are no initial winds. Note, the clouds are a very rough approximation based on the amount of condensation.
Clouds at 2 mins...
Clouds at 15 mins
Clouds at 60 mins
Initial Potential Temperature
2 min Potential Temperature
15 min Potential Temperature
60 min Potential Temperature
The values on the axes are kilometers... Ground Elevation ~1km.
Note the cloud that forms dies off, partly because there is no further source of moisture.
The key, at least for me, is that a mesoscale model needs to built around some assumed stable condition. This inhibits a sort of gravity wave that would be produced due to the fact of finite resolution. While there are still a few kinks and unknowns, the model remains stable for several hours. Another key is that computational diffusion is required, but the amount of computational diffusion which is needed is still somewhat unknown. Too little it goes hay wire, too much it goes hay wire. So, I have built the model with the amount of computational diffusion that I can select.
Below is a run from the model, starting with an area of higher potential temperate. Within this region I have also included some water vapor. There are no initial winds. Note, the clouds are a very rough approximation based on the amount of condensation.
Clouds at 2 mins...
Clouds at 15 mins
Clouds at 60 mins
Initial Potential Temperature
2 min Potential Temperature
15 min Potential Temperature
60 min Potential Temperature
The values on the axes are kilometers... Ground Elevation ~1km.
Note the cloud that forms dies off, partly because there is no further source of moisture.
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You can look at my page for weather modeling software for Windows. Do you provide the code of your model. Is it free for use or it is under some license?
