Skip to main content

Matsuno Analytical Wave Solution implemented in Python

Project description

pymaws: Matsuno Analytical Wave Solution implemented in Python

A python module for evaluating the initial conditions used in: The Matsuno baroclinic wave test case (under review for GEOSCI. MODEL DEV.).


pymaws has minimal requirements of:

  • Python 3.4 to 3.7
  • numpy 1.16

The package can be installed using pip:

$ pip install pymaws


The testing procedure tests all the parts of pymaws and should take anywhere from a few seconds upto 20 seconds due to random elements in the tests. To run the tests, use python3 in the command line:

$ python

You should get OK in the last line.

Getting Started

In the python environmnet, start by importing pymaws with the command:

$ from pymaws import *

The main function eval_field was loaded to your environment and a dictionary named Earth that stores the planetary parameters used in this package. (if you want to run eval_field with different parameters , see below)


Let's begin with a regular grid of lat/lon on a 20 second time interval:

$ import numpy as np
$ nlats = 100
$ nlons = 200
$ ntime = 50
$ lats = np.deg2rad(np.linspace(-80, 80, nlats))
$ lons = np.deg2rad(np.linspace(-180, 180, nlons))
$ time = np.linspace(0.0, 20, ntime)

Now, let's evaluate the meridional velocity field of an Eastward propagating Inertia-Gravity (EIG) wave:

$ v = np.zeros((ntime, nlats, nlons))
$ for t in range(ntime):
$     for j in range(nlats):
$         for i in range(nlons):
$             v[t, j, i] = eval_field(lats[j], lons[i], time[t], 
$                                           field='v', wave_type='EIG')

$ v.shape
$ (50, 200, 100)

Note that the default arguments of eval_field are n=1, k=5, amp=1e-5, wave_type='Rossby' and parameters=Earth. This package does not include visualizations of any kind, but you can use matplotlib, e.g.

$ from matplotlib import pyplot as plt
$ plt.contourf(np.rad2deg(lons), np.rad2deg(lats), v[0, :, :])
$ plt.xlim(-36,36)
$ plt.ylim(-30,30)

Meridional velocity at t=0 Meridional velocity at t=0


This version of pymaws does not solve Matsuno equations for n, k < 1,

Planetary Parameters:

The default parameters in pymaws are stored in a dictionary named Earth:

$  {'angular_frequency': 7.29212e-05,
      'gravitational_acceleration': 9.80616,
      'mean_radius': 6371220.0,
      'layer_mean_depth': 30.0}

If you want to use different planetary parameters, just copy the dictionary Earth and replace the appropriate values. For example lets change the layer_mean_depth parameter to 10 meters:

$   Earth_1 = Earth.copy()
$   Earth_1['layer_mean_depth'] = 10.0

When you run eval_field, remember to use the argument parameters=Earth_1.

How to cite pymaws

If you use pymaws in your academic work and publish a paper, we kindly ask that you cite pymaws using the following DOI:


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


Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

pymaws-0.1.0.tar.gz (9.9 kB view hashes)

Uploaded source

Built Distribution

pymaws-0.1.0-py3-none-any.whl (10.4 kB view hashes)

Uploaded py3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page