[MITgcm-support] viscAh & viscAz?

[Van Thinh Nguyen]

Dear all,

In oder to reduce the noises, I am playing with parameters viscAh & 
viscAz, so I have some questions, could someone please help me?

1. From the documentation, we can have two ways to set viscAh:
    a. By estimating velocity & grid scale
    b. By using viscAhReMax and/or viscC2Smag (or maybe combine with Leith
       viscosity)
   So, I understand that when I use option b) then I don't need to set
   viscAh or viscAz in &PARM01, is that correct?

2. Here are some options in data file:

  &PARM01
#
  viscAz=1.E-5,
  viscAh=1.E-5,
  tempAdvScheme=33,

  viscA4=0.E12,
  diffK4T=0.E4,
  diffKhT=1.E-5,
  diffKzT=1.E-5,
  diffK4S=0.E4,
  diffKhS=1.E-5,
  diffKzS=1.E-5,

  implicitDiffusion=.TRUE.,
  implicitViscosity=.TRUE.,

  viscC2leith=1.,
  viscC2leithd=1.,
##
  &
  &PARM04

  viscC2Gmag=4.,
  viscAhGridMax=0.5,

  &

I even try to increase viscAh & viscAz (to 1.E-1), as well as increase 
viscC2leith=viscC2leithd=1.
but I still get noises.
I know that you should know my simulation (problem &domain length scale) 
related to grid space (dX=10m) & time step (1s). However, I just wanna know
that my above options are correct or anything in conflict.

My problem has to be dealed with the range of viscAh=1.E-6 & 
viscAz=1.E-6, but I got stuck in this simulation due to the noises.

Thanks so much for your helps.


Van Thinh

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