Dear colleges, hello again!
I’ve successfully tested model with some of your previous suggestions during last months. Idea to use lower values of tkhmin, ktmmin and pat_len was really helpful. Now I continue my investigation with high-resolution domain (1 km), and I faced problem that model becomes numerically unstable and fails with nan-values (If I use reduced values of tkhmin, ktmmin and pat_len). Anso I made some tests with newer turbulent schemes (itype_turb = 5/7). In these tests results were better (in terms of the errors for nocturnal temperatures) than with itype_turb=3 and standard tuning parameters, but worse than with itype_turb=3 and tunned parameters (tkhmin, ktmmin and pat_len). And also experiments with itype_turb = 5/7 seems to have higher numerical stability that with itype_turb=3. In addition, this new schemes seems to be completely insensitive to tuning parameters that I used before.
No I have two main questions:
1) what model options I can use to avoid problems with numerical stability in case of itype_turb = 3 and corrected tuning parameters (dx = 1km, pat_len=50, tkhmin=tkmmin=0.05, dt = 5/10 sec).
2) are there any tuning parameters (ore some constants in the code), which can reduce mixing rates under stable conditions in case of usage itype_turb = 5/7?
Thanks in advance for your advices!
Dear colleges, hello again!
I’ve successfully tested model with some of your previous suggestions during last months. Idea to use lower values of tkhmin, ktmmin and pat_len was really helpful. Now I continue my investigation with high-resolution domain (1 km), and I faced problem that model becomes numerically unstable and fails with nan-values (If I use reduced values of tkhmin, ktmmin and pat_len). Anso I made some tests with newer turbulent schemes (itype_turb = 5/7). In these tests results were better (in terms of the errors for nocturnal temperatures) than with itype_turb=3 and standard tuning parameters, but worse than with itype_turb=3 and tunned parameters (tkhmin, ktmmin and pat_len). And also experiments with itype_turb = 5/7 seems to have higher numerical stability that with itype_turb=3. In addition, this new schemes seems to be completely insensitive to tuning parameters that I used before.
No I have two main questions:
1) what model options I can use to avoid problems with numerical stability in case of itype_turb = 3 and corrected tuning parameters (dx = 1km, pat_len=50, tkhmin=tkmmin=0.05, dt = 5/10 sec).
2) are there any tuning parameters (ore some constants in the code), which can reduce mixing rates under stable conditions in case of usage itype_turb = 5/7?
Thanks in advance for your advices!