SSH

[young...@gmail.com]

Dear Alan,

             Now I want to find the difference between  'sshflg' =0 and 1 diagnostic SSH flag (0=SSH,1=SSH&stericSSH) in the blkdat.input. And whether it could influence the SSH here. If so, how could I add it into the model. Whether I should get a script of relax_ssh.com to generate relax_ssh.ab files?

 

[alan.wa...@hycom.org]

When sshflg=1 the model calculates a steric SSH that is included in the output archive files.  Unless you include tides and a scalar SAL (which is less accurate than a prescribed or iterated SAL) this calculation is entirely diagnostic - it does not change the answers from HYCOM.  A steric SSH is an easy way to filter non-steric contributions, such as atmospheric pressure loading (mslprf=1) or tides.

See https://groups.google.com/a/hycom.org/d/msg/forum/3r60rtZr9w8/MBbprUVPAgAJ for a script to calculate the needed relax.ssh.[ab] file from a long term mean archive,  This entire thread is on this topic more or less, for example https://groups.google.com/a/hycom.org/d/msg/forum/3r60rtZr9w8/1lTeCoQnBAAJ

Alan.

[young...@gmail.com]

Dear Alan,

      Thanks very much. I have found that the veldf2, veldf4, thkdf4 files online are in global domain. Now I want to interpolate the files into the Pacific Ocean. Is it possible and is there a script to transform?

在 2018年1月10日星期三 UTC+8下午4:48:14，young...@gmail.com写道：

[alan.wa...@hycom.org]

Veldf4 and thkdf4 are constant in the Pacific.  Use veldf4=0.02 and thkdf4=0.01.  The veldf2 field is designed so that the Laplacian coefficient (often called A or A2) is 20 m^2/s everywhere on the Global 0.08 degree grid.  Since A2=veldf2*max(dx,dy) this means that veldf2 = A2/max(dx,dy).  See the attached example script.  You can change "20.0" to whatever you want, but note that there is a reason veldf2 is defined as a velocity - it allows the A2 to scale naturally with grid spacing.   The values  "3500.0 10000.0 " (allowed range of grid spacing) has been chosen for a 0.08 degree grid.  Or you could instead use a constant veldf2.

Alan.