CanyonbPy: CANYON-B Python

A Python implementation of CANYON-B (CArbonate system and Nutrients concentration from hYdrological properties and Oxygen using Neural networks) based on Bittig et al., 2018. It was developped from the MATLAB CANYON-B v1.0.

Features

Calculate macronutrients and carbonate system variables using CANYON-B neural network.

Installation

You can install canyonbpy using pip:

pip install canyonbpy

Usage

Here's a simple example of how to use canyonbpy with numpy:

from datetime import datetime
from canyonbpy import canyonb


# Prepare your data
data = {
    'gtime': [datetime(2024, 1, 1)],  # Date/time 
    'lat': [45.0],          # Latitude (-90 to 90)
    'lon': [-20.0],         # Longitude (-180 to 180)
    'pres': [100.0],        # Pressure (dbar)
    'temp': [15.0],         # Temperature (°C)
    'psal': [35.0],         # Salinity
    'doxy': [250.0]         # Dissolved oxygen (µmol/kg)
}

# Make predictions
results = canyonb(**data)

# Access results
ph = results['pH']           # pH prediction
ph_error = results['pH_ci']  # pH uncertainty

And now directly with xarray:

import xarray as xr
import canyonbpy  # accessor ds.canyonb is registered here

# ds must contain: time, latitude, longitude, pressure, temperature, salinity, doxy
ds = xr.Dataset(
    {
        "temperature": (("time", "pressure", "latitude", "longitude"), 16.0 * np.ones((2, 3, 3, 4))), 
        "salinity": (("time", "pressure", "latitude", "longitude"), 36.1 * np.ones((2, 3, 3, 4))),
        "doxy": (("time", "pressure", "latitude", "longitude"), 104 * np.ones((2, 3, 3, 4))),
    },
    coords={
        "time": ("time", [datetime(2014, 12, 9, 8, 45), datetime(2020, 12, 10, 8, 45)]),
        "pressure": ("pressure", np.array([180, 181, 182])),
        "latitude": ("latitude", np.array([17.6, 17.6, 17.6])),
        "longitude": ("longitude", np.array([-24.3, -24.3, -24.3, -24.3])),
    },
)

# Predict with CANYON-B
results = ds.canyonb.predict()

# CONTENT
results_content = ds.canyonb.content()

# results is an xr.Dataset with the same dims/coords as ds
print(results["pH"])       # xr.DataArray
print(results["pH_ci"])    # total uncertainty

# Merge predictions back into the source dataset
ds_enriched = xr.merge([ds, results])

Available parameters for prediction:

• AT: Total Alkalinity
• CT: Total Dissolved Inorganic Carbon
• pH: pH
• pCO2: Partial pressure of CO2
• NO3: Nitrate
• PO4: Phosphate
• SiOH4: Silicate

Documentation

Documentation is available here.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Citation

If you use this package in your research, please cite both the original CANYON-B paper and this implementation with the corresponding version for bug tracking (the example here shows all versions):

@article{bittig2018canyon,
  title={An alternative to static climatologies: Robust estimation of open ocean CO2 variables and nutrient concentrations from T, S, and O2 data using Bayesian neural networks},
  author={Bittig, Henry C and Steinhoff, Tobias and Claustre, Hervé and Körtzinger, Arne and others},
  journal={Frontiers in Marine Science},
  volume={5},
  pages={328},
  year={2018},
  publisher={Frontiers}, 
  doi={10.3389/fmars.2018.00328},
}

@software{bajon_canyonbpy,
  author    = {Bajon, Raphaël},
  title     = {canyonbpy: A Python implementation of CANYON-B},
  publisher = {Zenodo},
  doi       = {10.5281/zenodo.14765787},
  url       = {https://doi.org/10.5281/zenodo.14765787}
}