.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "examples/plot_diags_prior_eddies.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note :ref:`Go to the end ` to download the full example code. .. rst-class:: sphx-glr-example-title .. _sphx_glr_examples_plot_diags_prior_eddies.py: Diagnostics prior to eddy detection =================================== .. GENERATED FROM PYTHON SOURCE LINES 8-12 Initialisations ----------------- Import needed stuff. .. GENERATED FROM PYTHON SOURCE LINES 12-23 .. code-block:: Python import cmocean as cm import matplotlib.pyplot as plt import xarray as xr from shoot.dyn import get_geos, get_lnam, get_okuboweiss from shoot.grid import get_dx_dy from shoot.plot import create_map, pcarr from shoot.samples import get_sample_file xr.set_options(display_style="text") .. rst-class:: sphx-glr-script-out .. code-block:: none .. GENERATED FROM PYTHON SOURCE LINES 24-25 Read data .. GENERATED FROM PYTHON SOURCE LINES 25-30 .. code-block:: Python root_path = "OBS/SATELLITE/jan2024_ionian_sea_duacs.nc" path = get_sample_file(root_path) ds = xr.open_dataset(path).isel(time=0) # ds = ds.sel(longitude=slice(24, 34), latitude=slice(31, 35)) .. GENERATED FROM PYTHON SOURCE LINES 31-32 Compute grid metrics only once .. GENERATED FROM PYTHON SOURCE LINES 32-34 .. code-block:: Python dx, dy = get_dx_dy(ds) .. GENERATED FROM PYTHON SOURCE LINES 35-39 Geostrophic currents -------------------- ADT .. GENERATED FROM PYTHON SOURCE LINES 39-43 .. code-block:: Python fig, ax = create_map(ds.longitude, ds.latitude, figsize=(8, 5)) ds.adt.plot(ax=ax, cmap="cmo.balance", add_colorbar=False, transform=pcarr) ds.adt.plot.contour(ax=ax, transform=pcarr, colors="k", levels=20) .. image-sg:: /examples/images/sphx_glr_plot_diags_prior_eddies_001.png :alt: time = 2024-01-01 :srcset: /examples/images/sphx_glr_plot_diags_prior_eddies_001.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out .. code-block:: none .. GENERATED FROM PYTHON SOURCE LINES 44-45 Compute gestrophic current .. GENERATED FROM PYTHON SOURCE LINES 45-47 .. code-block:: Python ugeos, vgeos = get_geos(ds.adt, dx=dx, dy=dy) .. GENERATED FROM PYTHON SOURCE LINES 48-49 Compare them to dataset currents .. GENERATED FROM PYTHON SOURCE LINES 49-65 .. code-block:: Python fig0, ax0 = create_map(ds.longitude, ds.latitude, figsize=(8, 5)) kwqv = dict(units="dots", width=1, scale_units="dots", scale=1 / 20, transform=pcarr) ds.plot.quiver(x="longitude", y="latitude", u="ugos", v="vgos", color="k", ax=ax0, label="dataset", **kwqv) ax0.quiver( ds.longitude.values, ds.latitude.values, ugeos.values, vgeos.values, color="tab:orange", label="computed", **kwqv, ) plt.title("Geostrophic currents") plt.legend() .. image-sg:: /examples/images/sphx_glr_plot_diags_prior_eddies_002.png :alt: Geostrophic currents :srcset: /examples/images/sphx_glr_plot_diags_prior_eddies_002.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out .. code-block:: none .. GENERATED FROM PYTHON SOURCE LINES 66-72 Local normalized angular momentum ---------------------------------- The normalized angular momentum is computed at the center of 2D scanning window. Window in km .. GENERATED FROM PYTHON SOURCE LINES 72-74 .. code-block:: Python window_lnam = 50 .. GENERATED FROM PYTHON SOURCE LINES 75-76 Local normalized angular momentum .. GENERATED FROM PYTHON SOURCE LINES 76-78 .. code-block:: Python lnam = get_lnam(ds.ugos, ds.vgos, window_lnam, dx=dx, dy=dy) .. GENERATED FROM PYTHON SOURCE LINES 79-80 Plot .. GENERATED FROM PYTHON SOURCE LINES 80-85 .. code-block:: Python fig1, ax1 = create_map(ds.longitude, ds.latitude, figsize=(8, 5)) lnam.plot(cmap=cm.cm.diff, ax=ax1, add_colorbar=False, transform=pcarr) plt.title(f"Local angular momentum [{window_lnam}km]") .. image-sg:: /examples/images/sphx_glr_plot_diags_prior_eddies_003.png :alt: Local angular momentum [50km] :srcset: /examples/images/sphx_glr_plot_diags_prior_eddies_003.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out .. code-block:: none Text(0.5, 1.0, 'Local angular momentum [50km]') .. GENERATED FROM PYTHON SOURCE LINES 86-90 Okubo-Weiss ----------- Diagnostic .. GENERATED FROM PYTHON SOURCE LINES 90-93 .. code-block:: Python ow = get_okuboweiss(ds.ugos, ds.vgos, dx=dx, dy=dy) .. GENERATED FROM PYTHON SOURCE LINES 94-95 Plot .. GENERATED FROM PYTHON SOURCE LINES 95-99 .. code-block:: Python fig2, ax2 = create_map(ds.longitude, ds.latitude, figsize=(8, 5)) ow.plot(cmap=cm.cm.balance, ax=ax2, add_colorbar=False, transform=pcarr) ow.plot.contour(levels=[0], colors="k", transform=pcarr, ax=ax2) plt.title("Okubo-Weiss") .. image-sg:: /examples/images/sphx_glr_plot_diags_prior_eddies_004.png :alt: Okubo-Weiss :srcset: /examples/images/sphx_glr_plot_diags_prior_eddies_004.png :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out .. code-block:: none Text(0.5, 1.0, 'Okubo-Weiss') .. rst-class:: sphx-glr-timing **Total running time of the script:** (0 minutes 1.217 seconds) .. _sphx_glr_download_examples_plot_diags_prior_eddies.py: .. only:: html .. container:: sphx-glr-footer sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: plot_diags_prior_eddies.ipynb ` .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: plot_diags_prior_eddies.py ` .. container:: sphx-glr-download sphx-glr-download-zip :download:`Download zipped: plot_diags_prior_eddies.zip ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_