Fata Error: Minimum NO3 violated

Question

I am running AEM3D water quality simulation for a lake with CAEDYM flag turned on. The simulation abruptly ended after successfully running for the first three months. This happened after I changed the grid resolution from 100mx100m to 50mX50m. The low resolution grid simulation run for the entire model duration successfully with latest AEM3D model (2019-08-21 12:56:11 ) 

****FATAL ERROR******FATAL ERROR******FATAL ERROR******

* Minimum NO3 Violated for     1 cells

* Minimum value is -3.6379788E-12 at cell 20808

********************************************************************

It looks that I have to fix a threshold value of NO3 but I don't know which parameter actually this error is referring to and why it lead to crash after changing grid resolution.

Also the following WARNINGs were noted before fatal ending:

* Warning * Dissolved oxygen limit of 25 mg/l violated 

* Warning * 1 cell have been limited

* Warning * Settling velocity has not been set for File: PATH_inactive_WC.csv (I don't have this file format)

* Warning * Resuspension has not been set for File: PATH_inactive_WC.csv (I don't have this file format)

 

Help is greatly appreciated.

Thank you

Seyoum  

Answer 1

After doing some searching in the USER Guide, I found that a new minimum threshold for NO3 can be set in the run_aem3d.dat file. Also, the model can be forced to bypass checking max and min scalar thresholds if the "ihardlimit" parameter is set to zero in run_aem3d.dat file, but why the limit was exceeded when the model is changed to high resolution grid is not clear to me. Hope this helps some one in the future.