How to set horizontal advection of potential temperature as zero?

[Moqi]

Hello!

I would like to make the horizontal advection of potential temperature & water vapor within a certain range as zero. Although the compile was successful, when I set horizontal advection terms as zero variables associated with potential temperature or water vapor turned into 'nan'. Model would proceed normally once I kept those values unchanged. Is changing horizontal advection allowed in the model? If so, how should I make it?
I would be very appreciated if you could give me some advice on this issue!

Thanks

 

[kwerner]

Hi,
Do you mean that you would like potential temp and water vapor to remain static in one specific area of your domain - not advecting with the remainder of the systems? If so, I'm not sure if that is possible since model advancement depends on all of the evolving variables at each time and position. I believe this is the reason why you received "NaN" values when you tried this - because this then unbalances all the remaining variable values. I'm not sure if perhaps an idealized case would allow you to do this, but you could look into the details of each of those cases to see, and perhaps someone else on this forum will have had a similar experience they can share.