Ocean Modeling Discussion

Kate, I'd be very interested to know what solutions you come up with if you manage to pin it down, because I've grappled unsuccessfully with the same problem (I consider the extent to which I had to smooth my bathymetry/reduce my timestep to make it go away an unsuccessful fix). I had an especially ...

I thought about this problem a little bit more thoroughly, and it occurs to me that what is essentially a discontinuity every four steps (at least in my fields; it's very clear to me that 03-12 are cumulatively additive, as are 15-24) introduces a major problem when you try to do simple centered ave...

...good eye! Thanks! I think you're right; when I look at the forcing files generated with the conventional wisdom of these forums, my swrad (generated from ERA's ssr) and swflux (generated from ERA's e and tp) are clearly cumulatively additive through each set of four (00,03,06,09;12,15,18,21) 3-ho...

Hi everyone, Has Patrick Marchesiello (et al 2009)'s RSUP3 advection scheme to address spurious diapycnal mixing in sigma coordinate models been implemented in ROMS-Rutgers by anyone? The 2009 paper suggests it was going to be, but I don't see it in the latest release's cppdefs options or on the myr...

Hi Hernan, If you have the time, I have a clarification question. It's pretty trivial, so apologies in advance. I am curious what cpp options you recommend for the shortwave radiation in an application that forces with ERA-interim. I like SOLAR_SOURCE in general, to estimate heat penetration w/expon...

This is extremely helpful, thank you!

As a note, it looks like the server for your recommended dataset is moving to http://apps.ecmwf.int/datasets/data/interim_full_daily/ , so you may want to update your bookmark.

Hi everyone! I feel like I must be doing something fundamentally wrong in my application of ROMS to the northern California current at very high resolution. Since I'm pretty much self-taught from the forums, this does not come as a huge surprise to me, but it's definitely getting to be time to look ...

Hi everyone! I've run into an interesting problem: my ROMS run seems to be hanging, post-restart, on its first attempt to write a new timepoint into ocean_avg.nc (one model day after restarting). I think I've done everything normally; nrrec is -1, my ininame is my restart file, ldefout went to false...

Yeah, I really enjoy not having to do so anymore -- especially since all this arose from the challenge of recompiling after editing BCs, since last time I'd checked that was still necessary (as BCs were stored in .h)!

Thanks again for the responses, you two. I do appreciate your time.

Hi Kate -- thanks for the response. It actually occurred to me that I haven't updated my .in file in a long time; I know that a variety of things have changed, like how boundary conditions are now defined in .in instead of .h. So that's something to do, but I feel like it doesn't really explain the ...

Hi all, I've successfully compiled and run ROMS many times, but have never encountered a problem like this. I hadn't recompiled in the last several releases; when I finally needed to, it took a little bit of troubleshooting, in that I needed to revert the Linux-ifort.mk back to an older version that...

Investigating the bathymetry, the 0s were clearly set by the mask, possibly when processed by seagrid, which I used to generate my grid. I used these instructions, here, to make my bathymetry: (https://www.myroms.org/wiki/index.php/seagrid) and then afterwards used your smooth_bath.m to modify the o...

Actually, I did it with some care, using your matlab scripts and the instructions on the wiki. But obviously, not carefully enough!

Thanks for the insight,
Liz

I am reasonably confident in my forcing -- is there a way to tell whether ROMS is successfully interpolating from a coarser forcing grid onto the ROMS grid? As for CFL numbers, this is with the original 180s timestep. If I remember correctly, they need to be less than 0.5 or perhaps 0.25 depending o...

I turned off the diagnostic flags in my .h file and recompiled, then ran. Same blow-up at the second timestep (bear in mind that 3506880, on day 7306 since 01/01/1980, which is 01/02/2000, is the initial time): STEP Day HH:MM:SS KINETIC_ENRG POTEN_ENRG TOTAL_ENRG NET_VOLUME C => (i,j,k) Cu Cv Cw Max...

Gotcha, thanks. I fixed it by creating the coordinates attribute directly inside NCL before writing it to a .nc file. Now I've finally got a model that runs... until it blows up on first timestep it tries to advance. :( The heart of the problem in the logfile is definitely: STEP Day HH:MM:SS KINETIC...

I discovered that my forcing files were missing the 'coordinates = "lon lat"' attribute. I added it manually with NCO... I /think/ correctly, with, for example, ncatted -a coordinates,'lwrad_down',c,c,"lon lat" lwrad_down.ORG.2000.nc but something really weird pops up in the subs...

Nevermind, solved.

I have a similar problem, only it looks like this: Input Grid File: ocean_grd.nc Input Nonlinear Initial File: ocean_ini.nc Input Forcing File 01: swrad.ORG.2000.nc READ_PHYPAR - could not find input file: With no file name after the colon! There are eight forcing files in all, one apiece for the va...

Interpolation it is, then. I think I will try to use the myriad MATLAB tools available through myroms.org - there are so many, and they're so well-documented, that I might as well take advantage. (To those of you who've developed them, thanks!) In the long term I'm planning on three one-way nested g...

Thanks for the prompt reply! :) Before I go further, I guess I need to make sure -- does the lat/lon grid that ROMS expects have to be regular (in the 'evenly spaced lat/lon points' sense), thus requiring interpolation from the very irregular lat/lon grid in my dataset before I show it to ROMS at al...

So, on the topic of regridding winds from NARR data... here's a question that has more to do with basic netCDF processing than ROMS-specifics. (Sorry for that.) I've noticed that all of my data files from NCEP's NARR have a time dimension, and then x and y dimensions -- longitude and latitude are st...

I had to solve this problem recently (admittedly with 2009b, not 2010, but the error is the same). As far as I could find, there seem to be two schools of thought in these forums for how to deal with this particular seagrid2roms issue: 1. Recognize that MATLAB has their own netcdf commands and rewri...