Narwhal

Oceanographic data analysis in Python

Narwhal is a Python module built on pandas and matplotlib. Narwhal is designed for manipulating and visualizing oceanographic data.

Data are organized into self-describing Cast and CastCollection data structures. Convenience methods and functions are included for:

• interpolation
• density and depth calculation
• buoyancy frequency estimation
• baroclinic mode analysis
• water type fraction inversion

Quickly visualize results

The narwhal.plotting submodule contains convenience methods for creating T-S diagrams, cast plots, and section plots. Here's some data from off the coast of northeastern Greenland:

Python wrapper for the thermodynamic equation of state

Narwhal provides a ctypes wrapper for the Gibbs Seawater Toolbox in the narwhal.gsw submodule, making things like the following possible:

density = narwhal.gsw.rho(cast["sa"], cast["ct"], cast["p"])

Currently, GSW 3.05 is packaged with Narwhal.

Data should not be tied to software

For storage, data is serialized to JSON or HDF files. These common formats are open and easily imported into other analysis packages (such as MATLAB), or visualization libraries (such as D3).

Installation

git clone https://github.com/njwilson23/narwhal.git
pip install -r narwhal/requirements.txt
pip install narwhal

Dependencies

• Python 2.7+ or Python 3.4+
• pandas
• matplotlib
• scipy
• requests
• dateutil
• six
• C-compiler (for GSW)
• h5py (optional, required for HDF read/write)

If Karta is installed, it will be used for fast and accurate geographical calculations.

Narwhal is experimental. See also python-oceans and oce (R).