Tide Amplitude Extraction for TPXO model

[anupocean]

Hi,

I'm a new user of the pyTMD package and I'm trying to extract tidal amplitude and phase at multiple locations. Could you please guide me on which format of the tidal model data (NetCDF or binary) I should download to use with pyTMD?

Thank you!

[tsutterley]

Hi @anupocean,
They should both hopefully work. The binary files use the io.OTIS routines and the netCDF files use the io.ATLAS routines, but they should give equivalent predictions.

[anupocean]

Hi @tsutterley
Thank you so much reaching out.
Just to confirm—by TPXO9.1, do you mean the version that uses binary files with the io.OTIS routines, and by TPXO9-atlas-v5-nc, you're referring to the NetCDF version that works with the io.ATLAS routines in the currently in the model database? Let me know if I am wrong.

[tsutterley]

TPXO9-atlas-v5 is a set of binary files and TPXO9-atlas-v5-nc is a set of netCDF4 files. TPXO9.1 is a single binary file that is lower resolution (doesn't include outputs from the regional model runs). There is also now TPXO10-atlas-v2 available from the TPXO group.

[anupocean]

I noticed that TPXO10 is not listed among the available models in the pyTMD database. If I manage to get access to the TPXO10 version, will it still be compatible with the pyTMD package? I guess I should define it by myself.

[tsutterley]

TPXO10-atlas-v2 is available but you're right I don't have the lower resolution global model TPXO10. You're the first to ask for it :)

[tsutterley]

with the lower resolution global models, use the binaries

[anupocean]

Hi,
To add to this I would like to have a clarification on one more query. I was trying the plot the m2 constituent for the whole globe. For this I had downloaded the h_m2_tpxo10_atlas_30_v2.nc (TPXO10_atlas_v2). The nc file contains two variables hRe and hIm. So to convert into the amplitude and phase is this the correct approach. Am I correct to visualise the amplitude and phase using the calculations shown below.

amp = np.sqrt(hRe2 + hIm2)

####### Amplitude
amp = np.abs(z)

#########Phase
phase = np.arctan2(-hIm, hRe) * 180/np.pi
phase = np.mod(phase, 360) # wrap into [0, 360)

[tsutterley]

Yes. That would get you the amplitude in mm and the phase in degrees.

[anupocean]

Thank you @tsutterley .