physoce-datasets

A Python package and command line interface aimed at standardizing the access of various oceanographic datasets and calculating derived parameters according to modern best practices.

Why physoce-datasets?

This package provides an opinionated interface which aims to simplify and align access to datasets across providing institutions (NASA, ECMWF, etc.); as such, it is aimed primarily at those looking for streamlined data access. If you are an expert user who wants a lot of control over the details of the download and analysis process, this may not be for you. However, if you want:

• a unified command line and Python interface across datasets
• expert-informed derived variables such as wind stress and eddy kinetic energy
• long time series at a single or a few locations
• the simplest downloading and opening process possible

then this package is designed for you!

Install

uv

uv is the preferred way to manage this package. Please refer to the uv installation instructions. Once uv is installed, you can initialize a virtual environment with uv sync or you can run any commands directly with uv run and uv will handle the venv creation and activation auto-magically.

# add physoce-datasets to your project folder, equivalent to a pip install
uv add physoce-datasets
# you can now run physoce-datasets from your project folder
uv run physoce-datasets --help

Once you've added physoce-datasets to your project, you can import any of the download classes in your scripts:

# note the import uses underscore in place of dash
from physoce_datasets import copernicus_marine, era5, ooi_ea

Alternatively, you can run the command line interface from anywhere using uv tools:

# run physoce-datasets from the command line anywhere!
uvx physoce-datasets --help

pip

Of course, you can also use the classic pip, but you have to handle creating and activating the venv yourself:

python -m venv .venv
source .venv/bin/activate
pip install physoce-datasets

Credentials

Upon usage, this package may prompt for credentials to various data stores. Please refer to their documentation for how to access credentials and how credentials are stored:

• Copernicus Marine Services
• Copernicus Climate Data Store
• NASA Earthdata

Command Line Interface

Run the CLI with uv:

uv run physoce-datasets --help

Note that if you prefer the pip environment management, activate your environment according to the above and replace all uv run commands with python, e.g.:

python physoce-datasets --help

Top level commands are based on providing agency or program:

• copernicus-marine: Data from Copernicus Marine Services.
• era5: Data from ERA5 single levels.
• nasa: Data from NASA Harmony API. Currently not implemented due to issues with the API, see warning above.
• ooi-ea: Data from NSF Ocean Observatories Initiative Endurance Array.

Show provider command help, which will include available datasets for downloading:

uv run physoce-datasets ooi-ea --help

The specific dataset to download is specified after the provider:

uv run physoce-datasets ooi-ea profiler-chl --help

Available datasets are currently as follows:

• copernicus-marine
  • eke: Eddy kinetic energy derived from altimetric sea surface height anomalies.
• era5
  • wind-stress: Wind stress derived from ERA5 10 m winds using the COARE 3.5 algorithm.
• nasa
  • sst: Multi-scale Ultra-high Resolution (MUR) sea surface temperature. Currently not implemented due to issues with the API, see warning above.
• ooi-ea
  • mooring-ctd: Temperature, salinity, pressure, and density derived from mooring-mounted CTDs.
  • profiler-ctd: Mixed layer depth and stratification derived from temperature, salinity, pressure, and density from profiler-mounted CTDs.
  • profiler-chl: Chlorophyll a derived from profiler-mounted fluorometers.

Options

All command line interfaces share the same base options:

• --location: Location for the dataset in the format 'lon,lat' (e.g., '-132.0,36.55'). Required for all commands!
• --save-dir: Directory where the dataset file is written. If not set, defaults to .data/, relative to the current working directory.
• --save-file: File name to save the dataset. If not set, a default file name based on the data to be downloaded will be used.
• --start-date: Start date in YYYY-MM-DD format. If not set, uses 2000-01-01, or the earliest available date, whichever is later.
• --end-date: End date in YYYY-MM-DD format. If not set, uses the current date or the latest available date, whicher is earlier.

Examples

Run eke download with defaults:

uv run physoce-datasets copernicus-marine eke

Run wind-stress with specified options:

uv run physoce-datasets era5 wind-stress --save-dir data --save-file wind-stress.nc --start-date 2020-01-01 --end-date 2020-01-31 --location -130,45

Python Interface

Downloaders can also be used within Python scripts and Python notebooks as well.

Importing and initializing the classes takes similar arguments as the command line interface:

from physoce_datasets import copernicus_marine

# initialize the downloader
eke_downloader = copernicus_marine.EddyKineticEnergy(
    latitude=45,
    longitude=-130,
    start_date="2020-01-01",
    end_date="2020-12-31",
    save_dir="data",
    save_file="eke.nc",
)

# perform the download
eke_downloader.download()

# open the dataset; **kwargs are passed to underlying xr.open_dataset() call
ds = eke_downloader.open_dataset(**kwargs)

era5 and nasa downloaders follow the exact same interface.

The OOI Endurance Array downloaders follow a slightly different notation, using the site argument rather than latitude and longitude:

from physoce_datasets import ooi_ea

# initialize the downloader
eke_downloader = ooi_ea.ProfilerCTD(
    site="CE02SHSP",  # case insensitive
    start_date="2020-01-01",
    end_date="2020-12-31",
    save_dir="data",
    save_file="eke.nc",
)

Available profiler sites are CE01ISSP, CE02SHSP, CE04OSPS, CE04OSPD, CE06ISSP, CE07SHSP, CE09OSPM, and RS01SBPS.

Available mooring sites are CE01ISSM, CE02SHSM, CE04OSSM, CE06ISSM, CE07SHSM, and CE09OSSM.

More information on these sites can be found at the OOI Endurance Array, the OOI Cabled Endurance Array, and the OOI Cabled Continental Margin Array sites.

If you'd like to turn off logging in scripts, you can do so with the Python standard library logging module:

import logging

# supress info logging from physoce_datasets
logging.getLogger("physoce_datasets").setLevel(logging.WARNING)

Contributions

Do you have a publicly available dataset that you've got a great download script for? Do you have specialist knowledge required for calculating derived data products? Please consider opening an issue or submitting a pull request! We welcome any and all contributions to this project.

If you'd like to contribute to the code or documentation, please refer to the developer instructions below:

1. Create a fork of the repository.

2. Clone your fork to your local machine:

   git clone https://github.com/your-username-here/physoce-datasets.git
   cd physoce-datasets
   

3. Setup the development environment by installing development and documentation dependencies and installing pre-commit hooks:

   uv sync --dev
   pre-commit install
   

   If you're only updating code, you don't need the docs group. If you're only updating docs, you do need the dev group.

4. Create a new branch with a helpful name:

   git checkout -b your-great-new-feature
   

5. Make your code changes, stage them via git add, and commit them with git commit -m 'here's my great code changes'.

6. Push your changes to your fork using:

   git push -u origin your-great-new-feature
   

7. Open a pull request in the upstream repository.

Thanks so much for contributing to open source code!

AI Contribution Policy

We share the same AI Usage Policy as xarray. In short, this allows developers to use AI tools as a part of their development workflow, but requires that contributors understand all submitted code and take full responosiblity for their changes.