Search found 12 matches

by LiZhou
Mon Sep 28, 2020 1:06 pm
Forum: ROMS Adjoint
Topic: How to build the ADM individually?
Replies: 2
Views: 2130

Re: How to build the ADM individually?

wilkin wrote: Mon Sep 28, 2020 11:50 am Have you looked at the extensive set of tutorials, lectures and exercises at WikiROMS ...
https://www.myroms.org/wiki/4DVar_Tutorial_Introduction
Thanks very much. I did not follow this latest tutorial page. I will learn about it.
by LiZhou
Sun Sep 27, 2020 7:38 am
Forum: ROMS Adjoint
Topic: How to build the ADM individually?
Replies: 2
Views: 2130

How to build the ADM individually?

Hi,everyone.
Adjoint model is the key part of the 4D-Var assimilation systems, where it can provide gradients information of the cost function. BUT for ROMS, anybody knows how to conduct the AD-sensitivity experiments based on ADM? Any advice about .h and .in files? Thank you very much! :D :D
by LiZhou
Mon Jan 06, 2020 1:58 am
Forum: ROMS Adjoint
Topic: how to conduct adjoint sensitivity by ROMS ADM?
Replies: 1
Views: 1793

Re: how to conduct adjoint sensitivity by ROMS ADM?

Hi everyone: I try to open cppdef: FORWARD_RHS, FORWARD_MIXING, FORWARD_READ and AD_SENSITIVITY to do this. The input file ocean_ads.nc is necessary, and I create a new file following wc13_ads.nc, whcih contains the scope masking. Its compiling works, but when run the oceanM, it come to error like: ...
by LiZhou
Sun Jan 05, 2020 8:36 am
Forum: ROMS Adjoint
Topic: Adjoint Sensitivity Driver
Replies: 1
Views: 4101

Re: Adjoint Sensitivity Driver

Hi:
Thanks very much for your introduction of AD-sensitivity. For a practical application, would you like to provide a note about how to select cpp options when conducting AD-sensitivity with ROMS?
by LiZhou
Sun Jan 05, 2020 8:22 am
Forum: ROMS Adjoint
Topic: how to conduct adjoint sensitivity by ROMS ADM?
Replies: 1
Views: 1793

how to conduct adjoint sensitivity by ROMS ADM?

Hi: As we all know, the adjoint model is a powerful tool to analyse the sensitivity of your cost function on the initial/forcing states, whcih has been used in 4DVAR assimulation approach. As a noob of ADM of ROMS, I'm confused about how to build up this framework. The adjoint sensitivty is the key...
by LiZhou
Tue Aug 20, 2019 1:09 am
Forum: ROMS Adjoint
Topic: How to build a adjoint modelling framework in ROMS?
Replies: 1
Views: 2057

Re: How to build a adjoint modelling framework in ROMS?

I have done a unformed work about adjoint sensitivity of regional ocean state to initial errors. I set CPP h files like this: /* OPTIONS associated with tangent linear, representer and adjoint models:*/ /**for ADM_FWD*/ #undef FORWARD_RHS /* use if processing forward right-hand-side terms **/ #undef...
by LiZhou
Tue Aug 20, 2019 12:48 am
Forum: ROMS Adjoint
Topic: How to build a adjoint modelling framework in ROMS?
Replies: 1
Views: 2057

How to build a adjoint modelling framework in ROMS?

Hi,everyone: Adjoint model is a very useful tool to conduct a sensitivity study as well as optimization at a 4DVAR research. ROMS have been famous as a primitive ocean model with its own adjoint model. But, the discussion of ADM is little. How can we make a chat about how to buile ADM framework in R...
by LiZhou
Thu Mar 28, 2019 11:16 am
Forum: ROMS Ice
Topic: coupled ice options
Replies: 9
Views: 10932

Re: coupled ice options

Hi, What troubled me for a long time was that how to turn on or buildup a coupling to ice model(CICE etc) in a ROMS run. I have successfully achieved a quarter-resolution simulation of Southern Ocean(30S-75S) without coupling to a ice model, whcih may cause much deviation to real ocean state. My ROM...
by LiZhou
Wed Jan 23, 2019 6:50 am
Forum: ROMS Adjoint
Topic: what are the meanings of adjoint model's input and output
Replies: 3
Views: 3309

Re: what are the meanings of adjoint model's input and outpu

hi ezaron, Sorry about replying so late! And Thanks your suggestions very much! I'd have a try sincerely! Looking forward a new talk about this! Hi Li, Suppose you are interested in a linear function of the model's trajectory. Let the value of this function be denoted, y. Then there exists another f...
by LiZhou
Wed Jan 23, 2019 6:49 am
Forum: ROMS Adjoint
Topic: what are the meanings of adjoint model's input and output
Replies: 3
Views: 3309

Re: what are the meanings of adjoint model's input and outpu

hi ezaron,
Sorry about replying so late! And Thanks your suggestions very much! I'd have a try sincerely! Looking forward a new talk about this!
by LiZhou
Tue Oct 23, 2018 8:14 am
Forum: ROMS Adjoint
Topic: what are the meanings of adjoint model's input and output
Replies: 3
Views: 3309

what are the meanings of adjoint model's input and output

Dear all, I have a modeling test about sensitivty analysis of Southern Ocean's MKE to initial conditions. Therefor, I had to use ROMS ADM to preduct of the gradient of cost function J to initial perturbations(x0'). I'm confusing that what shoule be inputted at ADM modeling step. Is it the gradident ...
by LiZhou
Tue Oct 16, 2018 12:12 pm
Forum: ROMS Adjoint
Topic: Optimal Stochastic Calculation
Replies: 1
Views: 3961

Re: Optimal Stochastic Calculation

Hi, you mentioned you had successfully run NLM,TLM and ADM about CCS. I'm doing a similar simulation of my area. So, I'm wondering how to run TLM and ADM and weather you could provide related *.h and *.in file about them. Does Optimal Stochastic means a optimail initial condition or forcing? If so, ...