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    "## Plot Ocean Pole Tide Map\n",
    "Plots maps of the real and imaginary geocentric pole tide admittance functions from [Desai et al. (2002)](https://doi.org/10.1029/2001JC001224)\n",
    "\n",
    "- [IERS map of ocean pole tide coefficients](ftp://maia.usno.navy.mil/conventions/2010/2010_update/chapter7/additional_info/opoleloadcoefcmcor.txt.gz)\n",
    "\n",
    "#### Python Dependencies\n",
    " - [numpy: Scientific Computing Tools For Python](https://www.numpy.org)  \n",
    " - [matplotlib: Python 2D plotting library](http://matplotlib.org/)  \n",
    " - [cartopy: Python package designed for geospatial data processing](https://scitools.org.uk/cartopy/docs/latest/)  \n",
    "\n",
    "#### Program Dependencies\n",
    "\n",
    "- `io.ocean_pole_tide.py`: Read ocean pole load tide map from IERS\n",
    "- `utilities.py`: download and management utilities for files"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Load modules"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import matplotlib.pyplot as plt\n",
    "import cartopy.crs as ccrs\n",
    "import pyTMD.io\n",
    "import pyTMD.utilities"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Read ocean pole tide coefficient maps"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# read ocean pole tide map from Desai (2002)\n",
    "ocean_pole_tide_file = pyTMD.utilities.get_data_path(['data','opoleloadcoefcmcor.txt.gz'])\n",
    "iur,iun,iue,ilon,ilat = pyTMD.io.ocean_pole_tide(ocean_pole_tide_file)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Plot ocean pole tide maps"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fig,(ax1,ax2) = plt.subplots(ncols=2,sharex=True,sharey=True,figsize=(10,4),\n",
    "    subplot_kw=dict(projection=ccrs.PlateCarree()))\n",
    "ax1.imshow(iur.real.T,extent=(ilon[0],ilon[-1],ilat[0],ilat[-1]),origin='lower')\n",
    "ax2.imshow(iur.imag.T,extent=(ilon[0],ilon[-1],ilat[0],ilat[-1]),origin='lower')\n",
    "ax1.set_title('Radial Ocean Pole Tide (real component)')\n",
    "ax2.set_title('Radial Ocean Pole Tide (imaginary component)')\n",
    "ax1.coastlines(); ax2.coastlines()\n",
    "fig.subplots_adjust(left=0.01, right=0.99, bottom=0.10, top=0.95, wspace=0.05)\n",
    "plt.show()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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