Oregon State University (OSU) has developed an ocean loading and self-attraction file from TPXO9v2a for the following constituents: M2, S2, N2, K2, K1, O1, P1, Q1, Mm, Mf, M4, Mn4, Ms4, 2N2, S1. The file is in OTIS binary format and can be accessed through the scripts provided in the OTPS package, the TMD toolbox, or the pyTMD Python package. The load model is included in the OTPS software package, available at https://www.tpxo.net/otps
Direction for using the load tide to make tide predictions with the TMD toolbox v2.5
- Download the OTPS software package, available at https://www.tpxo.net/otps
The load tide model (load_file), located in the /DATA directory of the OTPS package
- Download the TPX09.v2a global model from https://www.tpxo.net/global and unpack into a directory.
This model provides the grid file and u file which are needed to create a “Model_file” which is currently required by version 2.5 of the TMD toolbox.
You must register, following instructions on the www.tpxo.net page, to download the TPXO global tide models.
- Create a directory on your computer called tpxo9v2a_load
- Copy the load_file from the OTPS package to the tpxo9v2a_load directory and rename it to h_load_file
- In the tpxo9v2a_load directory, create an ASCII “Model_file” named Model_tpxo9v2a_load. This file should contain the following lines of text, in the following order:
where “path” is the location of the TPX09.v2a global model you downloaded in step 2. Or, if you prefer, you can also add the path to your matlab script.
- You can then use tmd_tide_predict to predict the self-attraction and loading component of the tide for your location of interest. This can then be added to your tide prediction. Below is an example of a call to tmd_tide_predict:
Additional comments: This process will be simplified in the next release of the TMD toolbox: TMD3.0