Ocean Modeling Discussion

lmp4

So I've concluded this was 100% a problem with the inner and outer WRF domain discontinuities. As a test/fix we decided to create a 4km WRF/ROMS (single domain) coupled system (i.e. without any nesting) and ROMS runs smoothly without any issue in zeta or resulting blow-ups :D However, I'm not sure ...

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At the moment I have wetting and drying turned off. At the time I thought it might complicate things having it on and but I'll give it a go with it on!

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Here are the su/vstr fields about an hour before the simulation blows up and just when the typhoon makes landfall. I never noticed this but there seems to be somewhat the discontinuity between my outer and inner WRF domain (most notably for sustr in the affected delta). It's a small difference (0.08 ...

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I am constructing a high resolution coupled ROMS model of the South China Sea. To be specific I am looking at a strong realistic typhoon simulation with WRF 2KM coupled to ROMS 4KM via COAWST. However, I am finding continued issues near the coast just before the simulation ends. What’s strange is t ...

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For the last four months I’ve had this issue on my to do list and I think I’ve finally come to grips with what’s going on. So I have previously noted that the current ROMS-4DVAR formulation does not have an adjustment for near-equatorial geostrophic balance for the UV momentum balance [ https://www.m ...

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ROMS zeta is "absolute SSH" in the sense that it includes time mean and time varying SSH with respect to a datum (i.e. zeta=0) that is a geopotential surface, i.e. if zeta=constant there is no associated pressure gradient force. Altimetrists do not say "absolute" SSH so let me clarify: In altimetry ...

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The domain I am working with is quite near the equator -1S to -21S. This seems to be quite problematic for DA and especially since it seems that only a geostrophic balance is applied for updating the 3D UV momentum balance increments. The ECMWF NEMOVAR system deal with this by applying a β-plane ...

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Hi, I ran the I4D-Var module with my 10km model and now have an optimized initial condition. Now I have a 3km version of the model featuring the exact same domain. My question is could I run my 3km model with the optimal IC from my 10km model if I interpolate it? With my DA process I run from the ...

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Yeah that seems logical. Since I am running at such a high resolution shifting my domain away from the equator will take a while to set up so for now I think I'll create a 10km test model and see if it improves.

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Over the past few months I have been running into an issue I think I’ve finally got a grasp on! For context I am looking to perform some observational simulation studies in the Angola /Congo oceanic region (Lat: -1 to -21 S and Lon: 4.3 to 13.8 E). Now I have come across several setbacks in p ...

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Hi Alazhar, I had the exact same issue a few weeks ago with the same error as you have posted upon running it i.e. DEF_VAR - unable to define variable: CosWCosW. I will refer you to this post which I believe will solve your issue; https://www.myroms.org/forum/viewtopic.php?f=14&t=1370&p=4864&hilit ...

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I'd contact Willis and ask him.

lmp4

Hi, Sorry I forgot to follow up on this! I'd try contacting Willis (the author of the paper I linked to) directly

The database is actually a mat-lab file containing steric height corrections.

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Ok I've made a vital mistake! :( I didn't think to double check the units in varinfo.dat instead I just looked at the information given in mod_tides.F.... 'tide_Ephase' ! Input 'tidal elevation phase angle' 'degrees' ! [radians] 'SSH_Tphase, scalar, series' 'tide_period' 'idTzph' 'r2dvar' 0 ...

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If the ROMS code is correct, then is the formula presented in https://www.myroms.org/wiki/index.php/tide_start wrong? My phase angel is in degrees units from input so I assume somewhere within the code other from here it is converted into (degree/360) the standard units used as stated in mod_tides.F ...

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I think I've found a bug in how the contribution to sea surface height is added from a tidal forcing file. According to https://www.myroms.org/wiki/index.php/tide_start; the following formula is used to add the tides onto zeta. https://www.myroms.org/wiki/images/math/6/3/c ...

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I think I'm starting to get my head around the balance operator but I still am a little unsure about the standard deviations scripts and which to choose... Is my following logic correct? 1. d_std.m - Computes the 4dvar initial condition standard deviations. If I have chosen this method the balance ...

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Hi Arango, Thank you for your advice and sorry for the late response. I was using 5 loops since I wanted a quick test for the system, however after plotting the cost function you are correct in that the 4dvar algorithm was not converging. I must admit I am struggling to find a balance between ...

lmp4

*UPDATE* It works! :D Changed the time-step to 10 seconds... :? So that's now; Minimum barotropic Courant Number = 2.16784199E-03 Maximum barotropic Courant Number = 7.56383597E-02 Maximum Coriolis Courant Number = 5.22652060E-04 So since running the assimilation driver takes up alot of ...

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Having previously successfully assimilated SSTs, last week I moved on to starting to do some test SSH’s assimilation runs for the ROMS I4DVAR system for a 3km model of the Angola/Congo region. To summarize I have been having a major issue relating to assimilating SSHs into my model; • Model blows up ...

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I have been thinking about this alot recently; and to go off topic slighly I want to talk about the steric signal. All previous studies that have used AVISO SSH data have removed the steric signal. However I am really not sure how to do this myself... This paper http://www.geo.utexas.edu/courses ...

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The latest bug fix Ticket #658 https://www.myroms.org/projects/src/ticket/658 appears to target this issue with the CLIMA(ng) structure. I haven't tried to run this again but I shall assume this is sorted now

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This has resolved my issue as my model now compiles!

and thanks for the tip! I'll go through it and clean it up.

lmp4

Ok thanks! Now the references are stated in the following error message I get upon trying to compile ROMS up to -larpack ; COAWST/ROMS/Lib/ARPACK/PARPACK -lparpack -L/scratch/lp2314/COAWST/ROMS/Lib/ARPACK -larpack /scratch/lp2314/COAWST/Projects/4DVAR/Build_Angola_3km_4dvar/libADM.a(ad_step3d_t.o ...

lmp4

I came across this issue a few months ago and I've decided that I should try and see if anyone else has ever come across it. For my data assimilation (DA) application the original model (without the DA enabled) with the TS_MPDATA scheme performs better than other TS schemes. Therefore I want to run ...

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Still not getting anywhere with this! TS_MPDATA for the forward model really does perform much better

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I am indeed using the cpp settings TS_U3HADVECTION_TL & TS_C4HADVECTION_TL and thus only using TS_MPDATA for the forward model. My CPP settings are; #define TS_MPDATA /* Recursive MPDATA 3D advection turn ON */ #define TS_U3HADVECTION_TL /* 3rd-order upstream horiz. advection turn tangent linear ON ...

lmp4

I came across this issue a few months ago and I've decided that I should try and see if anyone else has ever come across it. For my data assimilation (DA) application the original model (without the DA enabled) with the TS_MPDATA scheme performs better than other TS schemes. The problem then seems ...

lmp4

Quick update on my last post, so changing to TS_MPDATA and TS_U3ADV_SPLIT made the model blowup, TS_A4VADVECTION however seemed to perform much better than TS_C4VADVECTION (my original setting). Here you can see the improvement where there is less cooling over the canyon as compared to using ...

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After looking at observations at 6 km resolution and changing my output to coarser resolution (6, 15, 30 km) I think I can conclude this is most definitely a computational artifact. At the moment I am using ERA-Interim for my atmo forcing, indeed interpolated before the run. Currently I am running ...

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I am running a high resolution application over the Congo/Angola region (3 km resolution) and upon running for a year I have noticed some cool SST's over a certain region in my domain. Specifically this region seems to be linked to the submarine canyon off the Congo river mouth. I have done a little ...

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I also am confused about this since I have just finished a 3 month run and had the exact same issue!
With my start date at 1st Jul, then after running for 3 months and my avg output says it is at 15 Aug?

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I too came across this problem recently and after reading ( Phase II, Major Overhaul of ROMS Kernel to Include Nesting) concluded that RadNud simply should not be used for the adjoint and tangent linear models, so I use RadNud for the NLM and clamped for the ADM and TLM. In 4D-Var data assimilation ...

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I am seeking to eventually apply weak constraint R4D-Var or 4D-PSAS to my model and am wondering about the type of model error that can be incorporated. Currently my model has a significant systematic error in temperature at a specific location in the domain (around +5K) for most months throughout ...

lmp4

Hi all, I am following the ROMS 4DVAR tutorials with the WC13 model and have come across an issue with the I4DVAR observation impact driver (Exercise 6). Firstly the model compiled fine with the obs impact driver enabled but would not proceed to run successfully. The error message was full of ...

lmp4

Originally I had only changed the library paths within the build script, however I have how changed it in both.

This has now resolved the issue and the WC13 model is now compiling!

Thank you for the swift reply and suggestions.

lmp4

Ok, I have successfully compiled both libarpack.a and libparpack.a. My mistake was a simple lack of reading the README file thoroughly enough, as a co-worker pointed out the use of the other ARmake sample scripts. Using the ARmake.MPI-Lunix I was then able to compile the libraries through changing ...

lmp4

I am experiencing some compile problems with Armake.inc when converting to an ifort compiler (my server does not have the pgf90 compiler). At first I have simply # the FFLAGS since I do not know the conversion to an intel compiler thus; FC = pgf90 #FFLAGS = -g FFLAGS = -u -Bstatic -fastsse -Mipa ...

Ocean Modeling Discussion

Search found 38 matches

Re: Coastal blow-ups issues: WRF typhoon to ROMS [via COAWST

Re: Coastal blow-ups issues: WRF typhoon to ROMS [via COAWST

Re: Coastal blow-ups issues: WRF typhoon to ROMS [via COAWST

Coastal blow-ups issues: WRF typhoon to ROMS [via COAWST]

SSH assimilation – No balance but UV still update?

Re: Use grided AVISO SLA data as observation data

4D-Var Balance : An addition for near equator domains

Coarse initial condition on high resolution same domain?

Re: Geostrophic Balance Breakdown? 4D-Var near the equator..

Geostrophic Balance Breakdown? 4D-Var near the equator...

Re: Compiling error when using AVERAGES_DETIDE in COAWST

Re: 'zeta' in ROMS

Re: 'zeta' in ROMS

Re: Possible bug in set_tides.F

Re: Possible bug in set_tides.F

Possible bug in set_tides.F

Re: Assimilating SSH – high res model blowup! Stability issu

Re: Assimilating SSH – high res model blowup! Stability issu

Re: Assimilating SSH – high res model blowup! Stability issu

Assimilating SSH – high res model blowup! Stability issue?

Re: 'zeta' in ROMS

Re: 4DVAR observation impact driver problem WC13

Re: TS_MPDATA and TS_U3HADVECTION_TL... Dsrc not found? I4DV

Re: TS_MPDATA and TS_U3HADVECTION_TL... Dsrc not found? I4DV

TS_MPDATA and TS_U3HADVECTION_TL... Dsrc not found? I4DVAR

Re: Compiling with TS_MPDATA and I4DVAR... Dsrc not found?

Re: Compiling with TS_MPDATA and I4DVAR... Dsrc not found?

Compiling with TS_MPDATA and I4DVAR... Dsrc not found?

Re: Cool SSTs over Congo's submarine canyon; is this realist

Re: Cool SSTs over Congo's submarine canyon; is this realist

Cool SSTs over Congo's submarine canyon; is this realistic?

Re: monthly data in average file

Re: When using the adjoint model, Rad+Nud boundary can't be

Weak constraint R4D-Var or 4D-PSAS: Systematic Model Errors?

4DVAR observation impact driver problem WC13

Re: ARPACK/PARPACK compile error WC13 I4DVAR

Re: ARPACK/PARPACK compile error WC13 I4DVAR

ARPACK/PARPACK compile error WC13 I4DVAR