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This table provides the values we've been using and explanation of what each quantity means.
ne30 v0 | ne30 v1 | ne120 before 8/10/16 | ne120 after 8/10/16 | Explanation | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| dtime | 30 min | 15 min | 15 min | Timestep used for most physics processes and for coupling between physics and dynamics | |||||||
| se_nsplit | 2 dt_remap=900s | 4 | 6* | dtime/se_nsplit = time between vertical remaps of the semi-Lagrangian vertical coordinate. | |||||||
| se_ | qsplitrsplit | 1 | 1 | 1 | dtime/(se_nsplit*se_qsplit) = timestep used for tracer advection (this should always be 1) | se_rsplit | 3 3 dt_tracer = 300s | 3 | 2* | dtime/(se_nsplit*se_qsplit*se_rsplit) = timestep used for dynamics calculationstracer timestep For ne30, dt_dyn tracers = 360s is probably stable, but we usually use 300s For ne120, dt_dyn tracers = 90s is probably stable, but we usually use 75s. | |
| se_qsplit | 1 | 1 | 1 | 1 | dtime/(se_nsplit*se_qsplit*se_rsplit) = timestep used for dynamics calculations This should always be 1, so that dt_dyn = dt_tracers. | ||||||
| hypervis_subcycle | 3 dt_vis = 100s | 4 | 4 | dtime/(se_nsplit_se_qsplit*se_rsplit*hypervis_subcycle) = timestep used for hyperviscosity calculation | |||||||
| hypervis_subcycle_q | 1 | 1 | 1 | dtime/(se_nsplit_se_qsplit*se_rsplit*hypervis_subcycle_q) = timestep used for hyperviscosity calculation in tracer advection (namelist_definition.xml indicates that only '1' is supported in CAM?) | |||||||
| cld_macmic_num_steps | 6 | 3* | 3 | Number of times the code surrounding macrophysics + microphysics is subcycled. This means that dtime/cld_macmic_num_steps = timestep used for macrophysics and microphysics. | |||||||
| clubb_timestep | 300 sec | 300 sec | 300 sec | I'm not sure what this means or how it relates to cld_macmic_num_steps | |||||||
| IRADSW | 2 steps | 4 steps (1 hr) | 4 steps (1 hr) | How frequently to compute SW radiation (in multiples of dtime). Radiation tendencies are taken from previous steps for steps when radiation is not recalculated. I think some scaling is made to account for zenith angle changes? | |||||||
| IRADLW | 2 steps | 4 steps | 4 steps | How frequently to compute LW radiation (in multiples of dtime). Radiation tendencies are taken from previous steps for steps when radiation is not recalculated. | |||||||
| *since AV1C-04 | *suggest to use |
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