Search found 6 matches

by Biswamoy_Paul
Mon Aug 26, 2019 5:02 am
Forum: ROMS Adjoint
Topic: W4DPSAS: not positive definite algorithm
Replies: 0
Views: 469

W4DPSAS: not positive definite algorithm

Hi, I am running W4DPSAS for the northern Indian Ocean with UKMO-EN4 obs. For a simulation of 5 days with 50 inner loops and 1 outer loop, I am getting the error: CONGRAD - Fatal error, not possitive definite algorithm: cg_delta = -5.76565447E+09 (001, 022) at the end of TLM for loop inner=22. Does ...
by Biswamoy_Paul
Tue Oct 30, 2018 12:55 pm
Forum: ROMS Usage
Topic: Assimilating only a particular type of observation
Replies: 0
Views: 671

Assimilating only a particular type of observation

Hello all, I am assimilating XBT, CTD and ARGO T & S Met office observation data using I4DVAR. I have generated one super obs file containing all these observations. Now I want to test the impact of assimilating only ARGO Temperature. So I set the parameters in s4dvar.in as follows: bgqc_type == 2 N...
by Biswamoy_Paul
Fri Jul 20, 2018 6:38 am
Forum: ROMS Adjoint
Topic: Inconsistent values of variables in TL initial condition
Replies: 3
Views: 1137

Re: Inconsistent values of variables in TL initial condition

Thanks, Kate for your reply. Yes, I was more focused on those extreme values in velocity and tracer fields. Those high anomalies are found even in the subsurface. I assume that the line of sharp gradient in velocity field, which is exactly on the Equator (my model domain ranges from 30S to 30N), is ...
by Biswamoy_Paul
Thu Jul 19, 2018 1:32 pm
Forum: ROMS Adjoint
Topic: Inconsistent values of variables in TL initial condition
Replies: 3
Views: 1137

Inconsistent values of variables in TL initial condition

I have setup IS4DVAR for the Indian Ocean with 8~9 km resolution and 40 vertical levels. I am testing a one day run with 30 inner loops and 1 outer loop using MetOffice EN4 T and S observation data. It is running fine till the adjoint run in the last inner loop. After the corresponding Descent Algor...
by Biswamoy_Paul
Thu May 17, 2018 2:00 pm
Forum: ROMS Discussion
Topic: ROMS-4DVar is not assimilating observations!
Replies: 0
Views: 727

ROMS-4DVar is not assimilating observations!

Hello, I am in process of implementing incremental strong constraint ROMS-4DVAR (I4D-Var) for the operational forecast of Indian Ocean. I have successfully tested the WC13 configuration in our cluster. Now I am trying to setup ROMS-4DVAR for the Indian Ocean with 1/12 deg resolution and 40 vertical ...
by Biswamoy_Paul
Tue Mar 29, 2016 10:16 am
Forum: ROMS Discussion
Topic: ROMS is running beyond its assigned time limits
Replies: 1
Views: 1576

ROMS is running beyond its assigned time limits

I am using ROMS (quarter degree) for Indian Ocean with forcing files ranging from 1-JAN-2002 to 31-DEC-2011. Initial condition is on 4-JAN-2003. I preassigned the time step DT = 600 and NTIMES = 17280 (four months). Now the problem is that when I am running the model it is running beyond its assigne...