.. _clouds:

Cloud Top Altitude
^^^^^^^^^^^^^^^^^^

The cloud top altitude is provided for scans where clouds are detected, and is otherwise set to NaN. This example
plots the average cloud top altitude in 2010 as a function of latitude for scans where clouds are detected.

.. code-block:: python

    import os
    import numpy as np
    import xarray as xr
    import matplotlib.pyplot as plt

    # load all of the version 7 data and set time as the dimension
    v7_folder = r'path\to\v7_data'
    data = xr.open_mfdataset(os.path.join(v7_folder, '*.nc'))
    data = data.swap_dims({'profile_id': 'time'})

    # group the data into 5 degree bins
    lat_bins = np.arange(-90, 91, 5)
    groups = data.cloud_top_altitude.sel(time='2010') \
                 .groupby_bins(data.latitude.sel(time='2010'),
                               bins=lat_bins, labels=lat_bins[1:] - 2.5)

    # plot the mean cloud top altitude in each bin
    (groups.mean(dim='time')).plot(x='latitude_bins', figsize=[6, 4])
    plt.ylim(5, 20)
    plt.xlabel('latitude')
    plt.ylabel('altitude [km]')

.. image:: ../images/ex_cloud_top_altitude.png
   :align: center