interpolation

[pooran]

Hi everybody,
I interpolated hycom data on a new grid, but I have a problem and the new interpolation file does not coincide on a grid in the boundaries,
could you please explain to me how to solve this problem?
looking forward to any suggestions.

Best,
Pooran

[kate]

I don't understand what you are saying. What exactly is the problem? What tools are you using?

[pooran]

I don't understand what you are saying. What exactly is the problem? What tools are you using?

Dear Kate,
Actually, I don't want to use Roms model, I am going to find a good way to interpolation hycom data ( with resolution 1/18 degree) on my grid ( with resolution 2 min).
I used cdo to do it, but I did not get a good interpolation in the boundaries.
I was wondering if you could tell me the best way to remap or interpolation data.

Thank you in advance.
Pooran

[kate]

Well, the steps you need to take might well depend on what you are planning to use the interpolated fields for. For ROMS, we typically use something like the scrip or ESMPy remapping tools for the horizontal remapping, but sometimes the land masks don't match and we need to do some lateral extrapolation too.

[pooran]

Well, the steps you need to take might well depend on what you are planning to use the interpolated fields for. For ROMS, we typically use something like the scrip or ESMPy remapping tools for the horizontal remapping, but sometimes the land masks don't match and we need to do some lateral extrapolation too.

Dear Kate,
I would really appreciate your useful information, if it is possible could you please tell me more details about extrapolation,
which software is good to do it? sorry if my question is simple, It is my first time to do this work.

Regards,
Pooran

[kate]

Well, it depends. I would use pyroms, others would use Matlab. pyroms comes with a HYCOM interpolation example using scrip (which has to be compiled).

[pooran]

Well, it depends. I would use pyroms, others would use Matlab. pyroms comes with a HYCOM interpolation example using scrip (which has to be compiled).

Many thanks for your help

[sonaljit.m]

You can also use basic python/matlab routines for interpolation. For my grids, I do interpolation from HYCOM/NCODA to the ROMS grid using scipy.griddata and scipy.interp1d.
griddata is for 2D interpolation: I use it for transforming the fields from HYCOM meshgrid to the ROMS meshgrid. And for the 1D interpolation from HYCOM vertical grid to ROMS sigma grid, I use interp1d.