Search found 10 matches

by xavierC
Wed Jul 10, 2019 8:29 am
Forum: ROMS Adjoint
Topic: CG_DELTA not positive OR Negative Ritz value found.
Replies: 0
Views: 184

CG_DELTA not positive OR Negative Ritz value found.

Hi, I am running quite successively some I4DVAR experiments. Also i am still working on understanding all the subtleties of 4DVAR, i am reasonably happy with my results. I made 3 runs (same domain, same forcing ) with 3 differents datasets (surface velocities) i run it daily with 8 inner loop and 1 ...
by xavierC
Thu Jun 20, 2019 9:58 am
Forum: ROMS Adjoint
Topic: depth of assimilated data
Replies: 2
Views: 428

Re: depth of assimilated data

I guess it is zeta related and that obs_depth is absolute and not relative to zeta.
by xavierC
Thu Jun 20, 2019 8:30 am
Forum: ROMS Adjoint
Topic: depth of assimilated data
Replies: 2
Views: 428

depth of assimilated data

Hi all, I am assimilating near surface current data with I4DVAR capability of ROMS. I noticed that the rejection of my data is strongly dependent from the depth i put them: i.e -pure surface (obs_depth=0) i get 100% data rejected -obs_depth=-7 i get almost 100% of data accepted -obs_depth=-1 i get a...
by xavierC
Wed May 29, 2019 2:31 pm
Forum: ROMS Problems
Topic: Noisy SST
Replies: 8
Views: 490

Re: Noisy SST

Hello,
thanks for your answsers, still have to try GLS or MY2.5, but I managed to try the "easy one" suggested by kate and i got a strong improvments of my solution. With some presistent noise only very near coast.
by xavierC
Tue May 28, 2019 12:32 pm
Forum: ROMS Problems
Topic: Noisy SST
Replies: 8
Views: 490

Re: Noisy SST

c.drinkorn wrote:Hi Xavier,

I switched from MIX_GEO_TS to MIX_S_TS in order to solve a similar problem at the bottom. Maybe it also helps you. :)

//Cate
Thanks a lot for your answer Cate. I just made a try, but no sucess once again...
by xavierC
Tue May 28, 2019 11:52 am
Forum: ROMS Problems
Topic: Noisy SST
Replies: 8
Views: 490

Noisy SST

Hello, I am doing some ROMS modelling and although it goes quite smooth, i have some noise on the temperature field, mainly at the surface, as you can see on the figure attached. I am using #define UV_ADV #define TS_U3ADV_SPLIT advections schemes (but i have tried others without any success) and i h...
by xavierC
Mon Apr 15, 2019 7:13 am
Forum: ROMS Tools and Techniques
Topic: How to edit a mask with pyroms
Replies: 2
Views: 479

Re: How to edit a mask with pyroms

Thanks Kate,
I kind of tried that and in the best scenario i had a window on which i could click e to activate/desactivate toogle.

Tried again and it is now working (may because i used the zoom)

Thanks for your answer.
Xavier
by xavierC
Fri Apr 12, 2019 3:20 pm
Forum: ROMS Usage
Topic: #define LIMIT_VDIFF #define LIMIT_VVISC
Replies: 0
Views: 238

#define LIMIT_VDIFF #define LIMIT_VVISC

Hi all, I went through severe stability problems during the last few days fighting with really intense eddies blowing up the model. I happens that this was solved by increasing the LIMIT_VDIFF and LIMIT_VVISC from 1e-3 to 1e-1 . i also had some success with 1e-2 but with a reduced time step. Where d...
by xavierC
Fri Apr 12, 2019 8:47 am
Forum: ROMS Tools and Techniques
Topic: sponge layer and diffusive advection schemes
Replies: 1
Views: 339

sponge layer and diffusive advection schemes

Hi, I am a bit lost with the use of the sponge layer through visc_factor in the grid file. Basically it modifies visc4 variable. But since i am using diffusive advection scheme i do not understand which values are in visc4 (which should be 0). Any one could give me any insight about proper sponge se...
by xavierC
Fri Apr 12, 2019 8:06 am
Forum: ROMS Tools and Techniques
Topic: How to edit a mask with pyroms
Replies: 2
Views: 479

How to edit a mask with pyroms

Hello,
Quite experienced with Agrif or NEMO i am new in using ROMS-rutgers. I would like to edit and correct my mask, but i don't really understand if and how i can do that with pyroms (i don't have matlab).
Any one could help with that ?
Thanks