From rajesh70530 at gmail.com  Tue Apr  7 01:43:19 2026
From: rajesh70530 at gmail.com (Killampalli Rajesh)
Date: Tue, 7 Apr 2026 11:13:19 +0530
Subject: [MITgcm-support] How to restore the surface currents for accurate
 simulation of submisoscale eddies.
Message-ID: <CAPQY=hmSRgndSCzfF=q70KhQ7jf6hxOwtufys591YPtPEqy5TA@mail.gmail.com>

Dear MITgcm Support Team,

I am running a regional MITgcm simulation (~3 km resolution) with
time-varying GLORYS boundary conditions (U, V, T, S, SSH). I observe bias
in surface currents (magnitude and direction), and mesoscale/submesoscale
eddies are not well captured in the interannual simulations.

I initially considered applying relaxation (nudging) the SST and SSS (e.g.,
via climatological relaxation or using boundary-driven constraints in
data.obcs). However, I understand that this not improving in the surface
currents.

I am considering whether surface current nudging (similar to SST/SSS) is
possible or advisable. Specifically:

   - Can pkg/ctrl be used to weakly/daily constrain surface currents or SSH?
   - Is there any recommended approach to improve surface currents without
   suppressing eddies?

Any guidance would be appreciated.

 Kind regards

```````````````````````````````````````````````

 Killampalli Rajesh (Research Scholar)

 Centre For Atmospheric Sciences,

 Indian Institute of Technology, Delhi

 Hauz Khas, New Delhi - 110016

 O-Email: asz238484 at iitd.ac.in
<rajesh93.cstaff at iitd.ac.in>

 P-Email:  rajesh70530 at gmail.com <rajesh93.cstaff at iitd.ac.in>

 Phone: +91 9492068095.
```````````````````````````````````````````````
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.mitgcm.org/pipermail/mitgcm-support/attachments/20260407/7ddae765/attachment.html>

From Martin.Losch at awi.de  Tue Apr  7 06:05:36 2026
From: Martin.Losch at awi.de (Martin Losch)
Date: Tue, 7 Apr 2026 12:05:36 +0200
Subject: [MITgcm-support] How to restore the surface currents for
 accurate simulation of submisoscale eddies.
In-Reply-To: <CAPQY=hmSRgndSCzfF=q70KhQ7jf6hxOwtufys591YPtPEqy5TA@mail.gmail.com>
References: <CAPQY=hmSRgndSCzfF=q70KhQ7jf6hxOwtufys591YPtPEqy5TA@mail.gmail.com>
Message-ID: <7102EB37-9B63-40F3-8A80-89B593A95013@awi.de>

Hi Killampalli,

you can use pkg/rbcs for that, there?s even some documentation: https://mitgcm.readthedocs.io/en/latest/phys_pkgs/rbcs.html

pkg/ctrl cannot be used for restoring.

Martin

> On 7. Apr 2026, at 07:43, Killampalli Rajesh <rajesh70530 at gmail.com> wrote:
> 
> Dear MITgcm Support Team,
> 
> I am running a regional MITgcm simulation (~3 km resolution) with time-varying GLORYS boundary conditions (U, V, T, S, SSH). I observe bias in surface currents (magnitude and direction), and mesoscale/submesoscale eddies are not well captured in the interannual simulations.
> 
> I initially considered applying relaxation (nudging) the SST and SSS (e.g., via climatological relaxation or using boundary-driven constraints in data.obcs). However, I understand that this not improving in the surface currents.
> 
> I am considering whether surface current nudging (similar to SST/SSS) is possible or advisable. Specifically:
> 
> Can pkg/ctrl be used to weakly/daily constrain surface currents or SSH?
> Is there any recommended approach to improve surface currents without suppressing eddies?
> Any guidance would be appreciated.
> 
>  Kind regards
> 
> ```````````````````````````````````````````````
> 
>  Killampalli Rajesh (Research Scholar)
> 
>  Centre For Atmospheric Sciences,
> 
>  Indian Institute of Technology, Delhi
> 
>  Hauz Khas, New Delhi - 110016
> 
>  O-Email: asz238484 at iitd.ac.in
>  <mailto:rajesh93.cstaff at iitd.ac.in>
>  P-Email:  rajesh70530 at gmail.com <mailto:rajesh93.cstaff at iitd.ac.in>
>  Phone: +91 9492068095.
> 
> ```````````````````````````````````````````````
> _______________________________________________
> MITgcm-support mailing list
> MITgcm-support at mitgcm.org
> http://mailman.mitgcm.org/mailman/listinfo/mitgcm-support

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.mitgcm.org/pipermail/mitgcm-support/attachments/20260407/65e74c38/attachment.html>