is this a method to comfirm model steady?

General scientific issues regarding ROMS

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xwbin
Posts: 20
Joined: Tue Aug 19, 2014 4:35 pm
Location: xiamen university

is this a method to comfirm model steady?

#1 Unread post by xwbin »

hi all,
I have a basic question.Please check my picture which I have uploaded in the attachment.
I used the hycom data to caculate the kenetic energy of the South China Sea by using the equation:1/2*m*(u*u+v*v) which I plot in bule line.To clarify the comparion,I just set m=2.
Also , I used the 'u_eastward' and 'v_northward' from the model output file,AVG.nc, to caculate the kenetic energy which includes 190 days'data and is showed in black line.Of course ,190 days is not over,the model is still running.
Here is my question can I say it completes "spin up" when the bule line is close enough to the black line ,and when both line has the same tendcy?
Thank you for you patience and looking forward to your replay!
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comparion.png
Last edited by xwbin on Fri Jul 03, 2015 11:44 am, edited 2 times in total.

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kate
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Location: CFOS/UAF, USA

Re: is this a method to comfirm model steady?

#2 Unread post by kate »

You don't tell us what the black line is - I assume that's your running ROMS model? So then what is the blue line? How was it computed?

Looking at diag.F, the kinetic energy there is computed in a volume-weighted way. In other words, each cell is KE times the cell volume, then you sum all those and divide by total volume to get the kinetic energy of the domain. I didn't see a density term.

xwbin
Posts: 20
Joined: Tue Aug 19, 2014 4:35 pm
Location: xiamen university

Re: is this a method to comfirm model steady?

#3 Unread post by xwbin »

kate wrote:You don't tell us what the black line is - I assume that's your running ROMS model? So then what is the blue line? How was it computed?

Looking at diag.F, the kinetic energy there is computed in a volume-weighted way. In other words, each cell is KE times the cell volume, then you sum all those and divide by total volume to get the kinetic energy of the domain. I didn't see a density term.
Thank you very much!As a new user,I really appreciate your help!And I think i need to view the diag.F to learn more.
Thank you for your explicit explain ,I know how to comfirm wether my model get stable.Thank you!
Last edited by xwbin on Thu Jul 09, 2015 12:53 pm, edited 1 time in total.

Ahumada
Posts: 11
Joined: Fri Jul 13, 2007 3:01 pm
Location: Universidad del Mar

Re: is this a method to comfirm model steady?

#4 Unread post by Ahumada »

Hi,

You should see an asymptotic curve... something like the figure in attached file. See, for example,

Marchesiello, P., McWilliams, J.C., Shchepetkin, A., 2001. Open boundary conditions for long-term integration of regional oceanic models. Ocean Modelling 3, 1-20.

Penven et al. (2005) Average circulation, seasonal cycle, and mesoscale dynamics of the Peru Current System: A modeling approach. J. Geophys. Res. 110, C10021

Gabersek S et al. (2007) The Sicily Channel Regional Model forecasting system: initial boundary conditions sensitivity and case study evaluation. Ocean Sci 3: 31-41

Happy modeling!

M.-A. Ahumada-Sempoal
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xwbin
Posts: 20
Joined: Tue Aug 19, 2014 4:35 pm
Location: xiamen university

Re: is this a method to comfirm model steady?

#5 Unread post by xwbin »

Ahumada wrote:Hi,

You should see an asymptotic curve... something like the figure in attached file. See, for example,

Marchesiello, P., McWilliams, J.C., Shchepetkin, A., 2001. Open boundary conditions for long-term integration of regional oceanic models. Ocean Modelling 3, 1-20.

Penven et al. (2005) Average circulation, seasonal cycle, and mesoscale dynamics of the Peru Current System: A modeling approach. J. Geophys. Res. 110, C10021

Gabersek S et al. (2007) The Sicily Channel Regional Model forecasting system: initial boundary conditions sensitivity and case study evaluation. Ocean Sci 3: 31-41

Happy modeling!
M.-A. Ahumada-Sempoal
Thank you for your patience and your picture ! You really help me a lot,and give me a good example.
I will read these references to learn more about model.
Running model gives me a lot of problems as well as so much fun.I am happy whwen I get these answers.Thank you very much!
Through the picture you showd me , I get my answer finnaly.Thank you!

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