[MITgcm-support] how to output vertical diffusivity？

[李 家宁]

Hello everyone,

  I’m running an ocean model with a spatial varying vertical diffusivity field, by setting “diffKrFile=diffKr.bin”. Meanwhile, The KPP package is disabled and the GMRedi (code is attached below) package is enabled.
  I wonder if the vertical diffusivity field would change with the model run, or it just keeps being its preset value. And how to output the vertical diffusivity field?
  I tried to look into the diffusive flux (DFrE_TH, DFrI_TH, DFrE_SLT and DFrI_SLT) produced by diagnostics package, but they have no pattern of the preset diffusivity. Is there any way to calculate the diffusivity by diffusive flux (As the unit of diffusive flux is ℃·m^3·s, it seems the diffusivity cannot be calculated by k = F/grad_z(theta))? Besides, I noticed the DFrE_SLT and DFrI_SLT are all zeros. Does that mean the salinity field has no diffusion? If so, how to set the salinity diffusivity?

Many thanks for any advice!

Jianing Li

data.gmredi:
# GM+Redi package parameters:

#-from MOM :
# GM_background_K:      G & Mc.W diffusion coefficient
# GM_maxSlope    :      max slope of isopycnals
# GM_Scrit       :  transition for scaling diffusion coefficient
# GM_Sd          :       half width scaling for diffusion coefficient
# GM_taper_scheme: slope clipping or one of the tapering schemes
# GM_Kmin_horiz  : horizontal diffusion minimum value

#-Option parameters (needs to "define" options in GMREDI_OPTIONS.h")
# GM_isopycK     : isopycnal diffusion coefficient (default=GM_background_K)
# GM_AdvForm     :      turn on GM Advective form       (default=Skew flux form)

 &GM_PARM01
  GM_background_K    = 1.e+3,
  GM_taper_scheme    = 'gkw91',
  GM_maxSlope        = 1.e-2,
  GM_Kmin_horiz      = 0.,
  GM_Scrit           = 4.e-3,
  GM_Sd              = 1.e-3,
 &
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