.. DO NOT EDIT. .. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY. .. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE: .. "sample_data/earth_geoid.py" .. LINE NUMBERS ARE GIVEN BELOW. .. only:: html .. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_sample_data_earth_geoid.py: Earth Geoid =========== The geoid is the equipotential surface of the Earth's gravity potential that coincides with mean sea level. It's often represented by "geoid heights", which indicate the height of the geoid relative to the reference ellipsoid (WGS84 in this case). Negative values indicate that the geoid is below the ellipsoid surface and positive values that it is above. The data are on a regular grid with 0.5 degree spacing and was generated from the spherical harmonic model EIGEN-6C4 [Forste_etal2014]_. .. GENERATED FROM PYTHON SOURCE LINES 19-37 .. image:: /sample_data/images/sphx_glr_earth_geoid_001.png :alt: Geoid heights (EIGEN-6C4) :class: sphx-glr-single-img .. rst-class:: sphx-glr-script-out Out: .. code-block:: none Dimensions: (latitude: 361, longitude: 721) Coordinates: * longitude (longitude) float64 -180.0 -179.5 -179.0 ... 179.0 179.5 180.0 * latitude (latitude) float64 -90.0 -89.5 -89.0 -88.5 ... 89.0 89.5 90.0 Data variables: geoid (latitude, longitude) float64 -29.5 -29.5 -29.5 ... 15.37 15.37 Attributes: (12/37) generating_institute: gfz-potsdam generating_date: 2018/12/13 product_type: gravity_field body: earth modelname: EIGEN-6C4 max_used_degree: 1277 ... ... maxvalue: 8.4722744E+01 meter minvalue: -1.0625734E+02 meter signal_wrms: 3.0584191E+01 meter grid_format: long_lat_value attributes: longitude latitude geoid attributes_units: deg. deg. meter | .. code-block:: default import matplotlib.pyplot as plt import cartopy.crs as ccrs import harmonica as hm # Load the geoid grid data = hm.datasets.fetch_geoid_earth() print(data) # Make a plot of data using Cartopy plt.figure(figsize=(10, 10)) ax = plt.axes(projection=ccrs.Orthographic(central_longitude=100)) pc = data.geoid.plot.pcolormesh(ax=ax, transform=ccrs.PlateCarree(), add_colorbar=False) plt.colorbar( pc, label="meters", orientation="horizontal", aspect=50, pad=0.01, shrink=0.6 ) ax.set_title("Geoid heights (EIGEN-6C4)") ax.coastlines() plt.show() .. rst-class:: sphx-glr-timing **Total running time of the script:** ( 0 minutes 0.663 seconds) .. _sphx_glr_download_sample_data_earth_geoid.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download sphx-glr-download-python :download:`Download Python source code: earth_geoid.py ` .. container:: sphx-glr-download sphx-glr-download-jupyter :download:`Download Jupyter notebook: earth_geoid.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_