Results at domain edges for limited-area simulations

[afernandezody]

Hello,
I'm analyzing some limited-area MPAS simulations into greater detail. Most of the general variables (e.g. wind speed) look like good, but the variables related to rain exhibit an unexpected phenomenon. The script doesn't add any extra variables so that rain-related variables include:
i_rainnc, rainnc, precipw, cuprec, i_rainc, rainc
It seems that 'cuprec' is the only variable quantifying rainfall rate so that has been the focus. The plots show bands of heavy rain at the domain edges that don't seem to be physically accurate. These bands appear intermittently and their locations move around as shown in the screenshots. I understand that the domain boundaries are always tricky in limited-area simulations but was wondering if anyone has noticed this behavior (maybe even with another variable). I was also wondering if they might show any sensitivity to resolution (haven't had time to perform any testing to check this hypothesis).
Thanks,
Arturo

 

[Ming Chen]

Arturo,
Regional MPAS lateral boundary zone contains 2-layer specified cells and 5-layer relaxation zone cells. In those specified zone cells, all variables are the same as the large scale forcing data, which leads to results inconsistent along the boundary.
When looking at simulations of regional MPAS, it is recommended to exclude results in these boundary zone cells.
Hope this is helpful for you. Please let me know if you have more questions.