Regarding salt flux parameterization

[yadusharma]

Hi all,

I was trying to understand the salt flux parameterization in ROMS. From the literature, I understand that there are virtual salt flux are real freshwater flux methods. Which one ROMS use when BULK_FLUX is on?. How can I get more information in this regard?. I would be grateful for any suggestions/comments on this.

Thanking you all.

[kate]

We certainly don't have a real fresh water flux, it's more of a negative salt flux when it rains.

[yadusharma]

Hi Kate
Thanks for your reply. . I have one more question. I have rivers in my model domain and also i have activated the BULK_FlUX option. I just want to know that, is there a way to "keep the surface freshwater flux unaffected" by the river inputs (Low Salinity and Temperature)which i want to experiment. I would be grateful for any suggestions in this.

[kate]

I don't know that what you ask is possible. Because we have the virtual salt flux, the salt flux from precip will depend on the surface salinity. If you change that with rivers, you will change the effect of E-P.

[yadusharma]

Hi Kate,
I found from the ROMS wiki that the surface salt flux with the RELAXATION is calculated as follows,
"
F_mod(:,:) = - Tnudg(isalt) * Hz(:,:,N) * [S_mod(:,:,N) - SSS(:,:)]
where Tnudg is a nudging time scale and Hz(:,:,N) is upper level thickness and Sea surface salinity (SSS) climatology".

But if I use SCORRECTION, how the above equation will be used/modified? .
I would be grateful for any suggestions regarding this.

[kate]

Both have the same equation, except in one case this is added to the existing salt flux and in the other case it replaces the existing salt flux.

[yadusharma]

Hi Kate,
Thanks for your reply. I have one more question, what value I should choose for Tnudg (TNUDG) in days?. If I want to use the SCORRECTION. Thanks again for your support and time.

[kate]

I don't care what you use, but you should know that in the trunk code, TNUDG is used for both SCORRECTION and for open boundaries, if you have them. I have opted to split them into two variables in my code. I've got the SCORRECTION one set to 90 days in most of my input files.