.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/hydrology/plot_16_monteith_canopy_resistance.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_api_gallery_hydrology_plot_16_monteith_canopy_resistance.py>`
        to download the full example code or to run this example in your browser via JupyterLite.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_api_gallery_hydrology_plot_16_monteith_canopy_resistance.py:


Monteith's canopy resistance (1965)
===================================

John Monteith treated a vegetated surface as one big leaf whose stomata add a
surface resistance in series with the aerodynamic resistance of the air above
it. Penman's equation becomes the Penman-Monteith equation, which reduces to
Penman's for a wet surface and falls as the stomata close. The example
computes the aerodynamic and surface resistances of the FAO reference grass
and the evaporation it gives, a few millimetres a day.

.. GENERATED FROM PYTHON SOURCE LINES 12-49



.. image-sg:: /api/gallery/hydrology/images/sphx_glr_plot_16_monteith_canopy_resistance_001.png
   :alt: Penman-Monteith: stomata throttle evaporation
   :srcset: /api/gallery/hydrology/images/sphx_glr_plot_16_monteith_canopy_resistance_001.png
   :class: sphx-glr-single-img





.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np

    from earthsciencekit.constants import CP_DRY_AIR, LATENT_HEAT_VAPORIZATION
    from earthsciencekit.hydrology import (
        aerodynamic_resistance,
        bulk_surface_resistance,
        penman_evaporation,
        penman_monteith_evaporation,
        psychrometric_constant,
    )

    air, pressure, density, deficit, energy = 293.15, 101325.0, 1.2, 1000.0, 150.0
    grass = 0.12  # m
    aerodynamic = aerodynamic_resistance(2.0, 2.0, 2 / 3 * grass, 0.123 * grass, 0.0123 * grass)
    surface = bulk_surface_resistance(100, 0.5 * 24 * grass)  # leaf area index 24 h for clipped grass
    reference = penman_monteith_evaporation(energy, air, deficit, density, aerodynamic, surface, pressure)
    wet = density * CP_DRY_AIR * deficit / (psychrometric_constant(pressure) * LATENT_HEAT_VAPORIZATION * aerodynamic)
    assert np.isclose(aerodynamic, 208 / 2, rtol=0.01) and np.isclose(surface, 70, rtol=0.01)
    assert np.isclose(
        penman_monteith_evaporation(energy, air, deficit, density, aerodynamic, 0, pressure), penman_evaporation(energy, air, wet, pressure)
    )
    assert 3 < reference * 86400 < 6

    resistance = np.linspace(0, 1000, 201)
    fig, ax = plt.subplots()
    for wind in (1.0, 2.0, 5.0):
        ra = aerodynamic_resistance(wind, 2.0, 2 / 3 * grass, 0.123 * grass, 0.0123 * grass)
        ax.plot(
            resistance, penman_monteith_evaporation(energy, air, deficit, density, ra, resistance, pressure) * 86400, label=f"wind {wind:g} m/s"
        )
    ax.plot(surface, reference * 86400, "ko", label=f"FAO grass reference, {reference * 86400:.1f} mm/day")
    ax.set(xlabel="surface resistance [s/m]", ylabel="evaporation [mm/day]", title="Penman-Monteith: stomata throttle evaporation")
    ax.legend()

    plt.show()


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.095 seconds)


.. _sphx_glr_download_api_gallery_hydrology_plot_16_monteith_canopy_resistance.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: lite-badge

      .. image:: images/jupyterlite_badge_logo.svg
        :target: ../../../lite/lab/index.html?path=api/gallery/hydrology/plot_16_monteith_canopy_resistance.ipynb
        :alt: Launch JupyterLite
        :width: 150 px

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_16_monteith_canopy_resistance.ipynb <plot_16_monteith_canopy_resistance.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_16_monteith_canopy_resistance.py <plot_16_monteith_canopy_resistance.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_16_monteith_canopy_resistance.zip <plot_16_monteith_canopy_resistance.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_