Description
Testing has shown that the default Tiedtke scheme produces a negative (weak) intensity bias in HAFS. Further testing has shown that modification of the scale-awareness calculation can mitigate and improve this bias. Specifically, the modifications are to reduce the "scale_fac" term to a square function instead of a cube, and to set scale_fac2 (for shallow convection) equal to scale_fac rather than scale_fac**0.5. This option is controlled by a namelist flag, scale_fac_opt.
Solution
Minor code changes. A namelist option is added. The default code remains the same.
Related to (optional)
ufs-community/ufs-weather-model#3100
Description
Testing has shown that the default Tiedtke scheme produces a negative (weak) intensity bias in HAFS. Further testing has shown that modification of the scale-awareness calculation can mitigate and improve this bias. Specifically, the modifications are to reduce the "scale_fac" term to a square function instead of a cube, and to set scale_fac2 (for shallow convection) equal to scale_fac rather than scale_fac**0.5. This option is controlled by a namelist flag, scale_fac_opt.
Solution
Minor code changes. A namelist option is added. The default code remains the same.
Related to (optional)
ufs-community/ufs-weather-model#3100