Search found 15 matches

by jayasankar
Thu Oct 04, 2018 9:00 pm
Forum: ROMS Usage
Topic: What would happen if LMD_BKPP is undefined in LMD scheme?
Replies: 5
Views: 1123

Re: What would happen if LMD_BKPP is undefined in LMD scheme

Thank you john.
I think the paper would help :D .
by jayasankar
Thu Oct 04, 2018 8:26 pm
Forum: ROMS Usage
Topic: What would happen if LMD_BKPP is undefined in LMD scheme?
Replies: 5
Views: 1123

Re: What would happen if LMD_BKPP is undefined in LMD scheme

Hi jc,

Thanks for the reply.I have gone through the link that has been given, however, it doesn't address each module separately nor it mentions a bottom boundary layer. I specifically would like to know what would happen if LMD_BKPP is undefined. Could you help.

Thanks a lot. jay
by jayasankar
Thu Oct 04, 2018 7:26 pm
Forum: ROMS Usage
Topic: What would happen if LMD_BKPP is undefined in LMD scheme?
Replies: 5
Views: 1123

What would happen if LMD_BKPP is undefined in LMD scheme?

Hi all, Could someone tell me what would happen if LMD_BKPP module is undefined while using other modules of LMD scheme? Also, I would be grateful if you could tell me where can read about all LMD modules. LMD_SKPP LMD_BKPP LMD_RIMIX LMD_CONVEC LMD_DDMIX LMD_NONLOCAL Thanks in adavance, Jayasankar
by jayasankar
Thu Sep 21, 2017 5:48 pm
Forum: ROMS Discussion
Topic: What should be the initial conditions for SPIN-UP?
Replies: 5
Views: 1243

Re: What should be the initial conditions for SPIN-UP?

hello Kate, I am so sorry, I think I have wasted your time for no reason. The blow-up happened was because, the file got corrupted in transfer (there was a small miss match in size). I changed it and its working with out any issues. My apologies and million thanks for your help and suggestions on a ...
by jayasankar
Thu Sep 21, 2017 5:09 pm
Forum: ROMS Discussion
Topic: What should be the initial conditions for SPIN-UP?
Replies: 5
Views: 1243

Re: What should be the initial conditions for SPIN-UP?

No, shorter time step is not helping. I was using 2400 sec (res- 0.2-0.25 deg) as time step and I even tried up to 600 sec

I didn't investigate the blow up properly, I have to do that.
by jayasankar
Thu Sep 21, 2017 4:57 pm
Forum: ROMS Discussion
Topic: What should be the initial conditions for SPIN-UP?
Replies: 5
Views: 1243

Re: What should be the initial conditions for SPIN-UP?

Hi Kate,

Thanks for the reply

I have tried with initial conditions extracted from Global model. To my surprise ended up in BLOW-UP on 28th (9*3+1 th year) year. I suspect its the initial conditions.

Jayasankar
by jayasankar
Thu Sep 21, 2017 12:02 pm
Forum: ROMS Discussion
Topic: What should be the initial conditions for SPIN-UP?
Replies: 5
Views: 1243

What should be the initial conditions for SPIN-UP?

HI all, I have to do a spin-up, and I am trying with a 3 yr simulation (say 1/1990 to 12/1992) in loop such that 10 such loops would give me a 30 year Spin-up. The boundary files are monthly data from a Global Ocean Model and surface fluxes are of 6-hrs. The global model is in 1 degree resolution an...
by jayasankar
Fri Sep 15, 2017 7:10 pm
Forum: ROMS Usage
Topic: How to deal with the blow-up at boundaries due to high wind?
Replies: 4
Views: 1839

Re: How to deal with the blow-up at boundaries due to high w

Hi,

I am trying not to compromise on the speed, hence i thought about reducing the wind velocities along the boundaries.

I am wondering if anyone had tried this way before, or if this would make noticeable variations in the model predictions in the entire domain.

Thank you.
by jayasankar
Fri Sep 15, 2017 5:03 pm
Forum: ROMS Usage
Topic: How to deal with the blow-up at boundaries due to high wind?
Replies: 4
Views: 1839

Re: How to deal with the blow-up at boundaries due to high w

Hi Kate, thank you for the suggestion , I am trying with time step.... Could you give me an idea about time steps used in various model in general? Is it normal to use time steps of 600 sec for a model with 0.25 degree grid resolution and maximum depth 5000m. Also, I'm kind of thinking about editing...
by jayasankar
Fri Sep 15, 2017 12:59 pm
Forum: ROMS Usage
Topic: How to deal with the blow-up at boundaries due to high wind?
Replies: 4
Views: 1839

How to deal with the blow-up at boundaries due to high wind?

Hello All, My simulations are getting terminated due to blow-up at boundaries, To be specific node like (1,2),(2,2),(1,4) etc... The wind velocities are very high in this region, around 12±5 m/s. Grid Resolution is 0.2 to 0.25 degrees, I have tried time steps 1800 sec and 1200 sec. Thank you, Jayasa...
by jayasankar
Fri Dec 16, 2016 9:23 pm
Forum: ROMS Discussion
Topic: High density at deeper layers
Replies: 3
Views: 1265

Re: High density at deeper layers

Thanks a lot Kate,

The potential density is within range. However the model computed density based on equation of state for seawater(Jackett and McDougall,1995) is around 1045kg/m3 at depths greater than 4000 meters.
by jayasankar
Fri Dec 16, 2016 3:26 pm
Forum: ROMS Discussion
Topic: High density at deeper layers
Replies: 3
Views: 1265

High density at deeper layers

Hello All, My simulation yields very high densities (around 1045 kg/m3) at deeper layers. There is no model instability though. Is this acceptable? If not what could be the reasons and how it be taken care of? I have used CFSR datasets for surface fluxes and SODA data for boundary fluxes. Thanks in ...
by jayasankar
Thu Dec 01, 2016 12:05 pm
Forum: ROMS Discussion
Topic: Optimum number of CPU-s to be used?
Replies: 1
Views: 757

Optimum number of CPU-s to be used?

Is there a thumb rule or an expression for the optimum number of CPUs to be used for a ROMS simulation?
by jayasankar
Wed Nov 23, 2016 10:27 pm
Forum: ROMS Problems
Topic: How to check if initial conditions are unbalanced or not?
Replies: 2
Views: 1666

Re: How to check if initial conditions are unbalanced or not

Hi Jvr, Thanks a lot for the prompt reply. yes the IC file contains all needed data. The IC file is made by interpolating SODA data. So as you said it could probably be the geometry of my model. The model was instable and I found that the density was rising through out the domain. So I tried to smoo...
by jayasankar
Tue Nov 22, 2016 9:43 am
Forum: ROMS Problems
Topic: How to check if initial conditions are unbalanced or not?
Replies: 2
Views: 1666

How to check if initial conditions are unbalanced or not?

Hi all, I have been trying to setup a model and it is resulting in BLOW UP in like 10-30 steps depending up on grid configuration and time step. I guess it is because of the initial conditions, temperature and salinity.. How to see if they are unbalanced or not, and how to correct the same? Could it...