Hi all,
I am using CMAQ-5.4 to run the 12US1 case for July 2021. I downloaded emissions and BCs from the website (https://2021platform.s3.amazonaws.com/index.html#2021platform/12US1/) and used the hemispheric output as ICs (https://drive.google.com/drive/folders/11G3eAcs7WFKuRP1AhzD4PWBsslPZrL6Q). I used the cb6mp_ae6_aq and ae6_mp mechanism. I run the model on NCAR derecho. The model can run but generated the FLOOR files showing negative values at high altitude:
Concentrations less than, but reset to 0.000E+00 in VDIFF
Date:Time Col Row Layer Species Value before reset
2021182:002100 14 74 32 184 (ASO4K ) -1.250E-06
2021182:002100 15 74 32 184 (ASO4K ) -1.355E-06
2021182:002100 16 74 32 184 (ASO4K ) -1.458E-06
2021182:002100 17 74 32 184 (ASO4K ) -1.544E-06
2021182:002100 18 74 32 184 (ASO4K ) -1.622E-06
2021182:002100 19 74 32 184 (ASO4K ) -1.693E-06
2021182:002100 20 74 32 184 (ASO4K ) -1.771E-06
2021182:002100 21 74 32 184 (ASO4K ) -1.868E-06
2021182:002100 22 74 32 184 (ASO4K ) -1.962E-06
2021182:002100 23 74 32 184 (ASO4K ) -2.045E-06
2021182:002100 24 74 32 184 (ASO4K ) -2.102E-06
2021182:002100 25 74 32 184 (ASO4K ) -2.149E-06
2021182:002100 26 74 32 184 (ASO4K ) -2.191E-06
2021182:002100 27 74 32 184 (ASO4K ) -2.370E-06
2021182:002100 28 74 32 184 (ASO4K ) -2.411E-06
2021182:002100 29 74 32 184 (ASO4K ) -2.454E-06
2021182:002100 30 74 32 184 (ASO4K ) -2.496E-06
2021182:002100 31 74 32 184 (ASO4K ) -6.515E-07
2021182:002100 14 74 32 190 (ANO3K ) -2.264E-08
2021182:002100 15 74 32 190 (ANO3K ) -3.038E-08
2021182:002100 16 74 32 190 (ANO3K ) -3.748E-08
2021182:002100 17 74 32 190 (ANO3K ) -4.348E-08
2021182:002100 18 74 32 190 (ANO3K ) -4.869E-08
2021182:002100 19 74 32 190 (ANO3K ) -5.282E-08
2021182:002100 20 74 32 190 (ANO3K ) -5.691E-08
2021182:002100 21 74 32 190 (ANO3K ) -6.183E-08
2021182:002100 22 74 32 190 (ANO3K ) -6.645E-08
2021182:002100 23 74 32 190 (ANO3K ) -6.923E-08
2021182:002100 24 74 32 190 (ANO3K ) -7.221E-08
2021182:002100 25 74 32 190 (ANO3K ) -7.507E-08
2021182:002100 26 74 32 190 (ANO3K ) -7.778E-08
2021182:002100 27 74 32 190 (ANO3K ) -9.430E-08
2021182:002100 28 74 32 190 (ANO3K ) -9.758E-08
2021182:002100 29 74 32 190 (ANO3K ) -1.004E-07
2021182:002100 30 74 32 190 (ANO3K ) -1.029E-07
2021182:002100 14 74 32 195 (ACLK ) -1.388E-06
2021182:002100 15 74 32 195 (ACLK ) -1.482E-06
2021182:002100 16 74 32 195 (ACLK ) -1.570E-06
2021182:002100 17 74 32 195 (ACLK ) -1.643E-06
2021182:002100 18 74 32 195 (ACLK ) -1.705E-06
2021182:002100 19 74 32 195 (ACLK ) -1.762E-06
I searched for similar problems on the CMAS forum and it seems if it is ok if it happens rarely. But i have the FLOOR files generated every days of the simulation with a lot of lines in each FLOOR file. I tried to use a shorter timestep but the preoblem is still there. Does anyone know how to solve this issue? Any suggestions are appreciated.
Thanks,
Lin