Ocean Modeling Discussion

Research Scientist - Coastal Oceanographer 21322 - DARWIN, NORTHERN TERRITORY About AIMS The Australian Institute of Marine Science (AIMS) is Australia’s tropical marine research agency. Our research into some of Australia’s iconic marine ecosystems guides their management and that of similar system...

Oceanographic drivers of coral reef connectivity off northwestern Australia A PhD scholarship is available to support a joint research project between the UWA Oceans Institute (http://www.oceans.uwa.edu.au/) at the University of Western Australia and the Australian Institute of Marine Science (AIMS...

The Australian Institute of Marine Science (AIMS) is a world leader in tropical marine science and conducts research supporting environmental sustainability and economic growth in Australia’s tropical oceans. Through our highly skilled and innovative staff, state-of-the-art infrastructure, strong na...

Hi, I'd like to follow-up on this topic if it's still being investigated. I'm using this model configuraton (probably different model forcing) and the tiling issue appeared when I started using terms from the temperature equation (ocean_dia.nc). Below is a figures of the depth-averaged (upper 60 m),...

Yes, I was using EW_PERIODIC. I could try the f-plane but I've decided to just use cartesian coordinates since it eliminated the noise that was present with spherical coordinates.

Jessica

This 2-dx grid noise started turning up in one of my other set-ups, similar configuration but with a closed basin. The noise did not arise when I switched from spherical to cartesian coordinates. I need to test whether making this switch will fix the noise in this channel set-up, but I suspect it wi...

Hi, I appreciate the help. I really want to figure this out. I was wondering if tiling was an issue. I tried NtileI = 1, NtileJ = 8 with the same ocean_ini.nc file and the model output appears to be the same. The 2dx-noise appears when a larger scale mode structure develops after about 1.5 years. Wh...

I'm trying to eliminate the 2-dx grid noise in the temperature and flow field. In order to examine the baroclinic instability problem, I am currently inputting an initial perturbation to the u-field in the ocean_ini.nc file. The initial perturbation is randomly generated via matlab and within [-0.01...

With MPDATA turned off, the noise is worse. I can include a figure if you'd like. Any other possible advection schemes that might help?

Jessica

Hi, I've been working on a zonal channel flow problem on a beta-plane. An initial surface mixed layer is specified to about 200 m deep, with a surface temperature gradient. A small perturbation is input into the zonal flow. I've been having problems with 2-dx grid noise and I haven't been able to ge...

Hi, Have you looked at how the density fields adjust adjacent to these regions of steep topography? The flows that you show are in the direction that one would find for a diffusively-driven flow, with an upslope Ekman transport. The strength of this flow is dependent on the slope angle and the verti...

Great- thanks for letting me know!

-Jessica

Hi, I just want to clarify the units used for the biharmonic mixing coefficients. The constants specified for VISC4 and TNU4 have units of m^4 s^-1 in the .in-file. However, I noticed that in mod_scalars.F, visc4 and tnu4 are described as being the 'square root lateral biharmonic constant mixing coe...

Hi, I had a question about the horizontal grid set-up in ana_grid.h for BL_TEST, in which 'dx' is a function of the x-coordinate. I am interested in using nonuniform horizontal grid resolution and in specifying my grid following this form. When running BL_TEST, I noticed that the locations of the x_...

Hi John, I understand that the bottom stress, bustr, is calculated in set_vbc.F, as you mentioned. I'm interested in using the no-slip boundary condition. From the linear bottom stress, we know that Km (du/dz) = rdrg*u at the bottom u-grid point, where u is calculated at a distance dz above the bott...

Thanks for your suggestions. I will go ahead and try using the UV_LOGDRAG option.

Sorry about the typo, I meant that -.1 was +.1.

-J

Hi, is there a way to use a no slip bottom boundary condition with ROMS? I realize that you can choose logarithmic, linear, or quadratic bottom drag. I tried to specify a no slip BC by choosing a linear bottom drag and setting rdrg = +.1 to 10.0, but in each case the model blows up. Thanks for any s...