cdasws Example Jupyter Notebook

This Jupyter notebook demonstrates using the cdasws Python package to access NetCDF data from cdaweb with the data returned in the xarray.Dataset. This notebook contains the following sections:

1. Prerequisites
2. Setup
3. Get Observatory Groups
4. Get Datasets
5. Get Dataset Variables
6. Get Data
7. Display Metadata
8. Plot Values
9. Additional Documentation

Notes:

1. This example only depends upon pure Python modules and does not require modules that depend upon non-Python code (such as spacepy and pycdf).
2. The use of the dataRepresentation keyword parameter below is only necessary if you also have spacepy installed.
3. It also is possible to have the data returned in a SpasePy data model instead of an xarrayDataset.

Prerequisites

Install the prerequisite software from the Python Package Index if it is not already installed.

%pip install xarray cdflib cdasws -q

Note: you may need to restart the kernel to use updated packages.

Setup

Execute some preliminary code that is necessary before the code that follows.

from cdasws.cdasws import CdasWs
from cdasws.datarepresentation import DataRepresentation as dr
import matplotlib.pyplot as plt
cdas = CdasWs()

Get Observatory Groups

The following code demonstrates how to get the available observatory groups.

obs_groups = cdas.get_observatory_groups()
for index, obs_group in enumerate(obs_groups):
    obs_group_name = obs_group['Name']
    if 'ICON' in obs_group_name:
        print(obs_group_name)

ICON

Get Datasets

The following code demontrates how to get a list of datasets.

datasets = cdas.get_datasets(observatoryGroup='ICON')
for index, dataset in enumerate(datasets):
    print(dataset['Id'], dataset['Label'])

ICON_L2-1_MIGHTI-A_LOS-WIND-GREEN Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) Sensor A: Line-of-sight Wind Profiles - T. J. Immel (UC Berkeley>SSL)
ICON_L2-1_MIGHTI-A_LOS-WIND-RED Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) Sensor A: Line-of-sight Wind Profiles - T. J. Immel (UC Berkeley>SSL)
ICON_L2-1_MIGHTI-B_LOS-WIND-GREEN Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) Sensor B - Line-of-sight Wind Profiles - T. J. Immel (UC Berkeley>SSL)
ICON_L2-1_MIGHTI-B_LOS-WIND-RED Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) Sensor B - Line-of-sight Wind Profiles - T. J. Immel (UC Berkeley>SSL)
ICON_L2-2_MIGHTI_VECTOR-WIND-GREEN MIGHTI - Cardinal Vector Winds - T. J. Immel (UC Berkeley>SSL)
ICON_L2-2_MIGHTI_VECTOR-WIND-RED MIGHTI - Cardinal Vector Winds - T. J. Immel (UC Berkeley>SSL)
ICON_L2-3_MIGHTI-A_TEMPERATURE ICON MIGHTI-A Level 2.3 Retrieved Temperature File - T. J. Immel (UC Berkeley>SSL)
ICON_L2-3_MIGHTI-B_TEMPERATURE ICON MIGHTI-B Level 2.3 Retrieved Temperature File - T. J. Immel (UC Berkeley>SSL)
ICON_L2-4_FUV_DAY ICON FUV Daytime: column density ratio of thermospheric atomic oxygen to molecular nitrogen.  - T. J. Immel (UC Berkeley>SSL)
ICON_L2-4_FUV_DAY-LIMB ICON FUV Daytime Limb - T. J. Immel (UC Berkeley > SSL)
ICON_L2-5_FUV_NIGHT FUV Short Wavelength Channel - 135.6 Altitude Profiles (night) - T. J. Immel (UC Berkeley>SSL)
ICON_L2-6_EUV ICON EUV derived ionospheric data products - T. J. Immel (UC Berkeley>SSL)
ICON_L2-7_IVM-A ICON Ion Velocity Meter (IVM) Thermal Plasma Measurements - T. J. Immel (UC Berkeley>SSL)
ICON_L2-7_IVM-B ICON IVM Thermal Plasma Measurements B - T. J. Immel (UC Berkeley>SSL)

Get Dataset Variables

The following code demonstrates how to get a dataset's variables.

ds_id = 'ICON_L2-4_FUV_DAY'
var_names = []
variables = cdas.get_variables(ds_id)
for variable in variables:
    var_name = variable['Name']
    var_names.append(var_name)
    print(var_name, variable['LongDescription'])

ICON_L24_1356_Emission Disk short wave emission
ICON_L24_Ap Ap used in retreival
ICON_L24_Disk_LOS_Zen_Angle Retrieved disk LOS zenith angle
ICON_L24_Disk_Latitude Retrieved disk latitude
ICON_L24_Disk_Longitude Retrieved disk longitude
ICON_L24_Disk_ON2 Retrieved disk column O/N2
ICON_L24_Disk_SZA Retrieved disk SZA
ICON_L24_Disk_Sigma_ON2 Retrieved disk column O/N2 uncertainty
ICON_L24_LBH_Emission Disk long wave emission

Get Data

The following code demonstrates how to get NetCDF data from the ICON_L2-4_FUV_DAY dataset.

data = cdas.get_data(ds_id, var_names,
                     '2022-11-24T23:00:00Z', '2022-11-24T23:05:00Z',
                     dataRepresentation = dr.XARRAY)[1]
print(data)

<xarray.Dataset> Size: 57kB
Dimensions:                      (Epoch_cdf: 24, record0: 6951)
Coordinates:
  * Epoch_cdf                    (Epoch_cdf) datetime64[ns] 192B 2022-11-24T2...
Dimensions without coordinates: record0
Data variables:
    time_base                    datetime64[ns] 8B 1970-01-01
    ICON_L24_1356_Emission       (Epoch_cdf) float32 96B 3.877e+03 ... 3.661e+03
    ICON_L24_Ap                  (Epoch_cdf) float32 96B 9.0 9.0 9.0 ... 9.0 9.0
    ICON_L24_Disk_LOS_Zen_Angle  (Epoch_cdf) float32 96B 119.9 119.9 ... 119.9
    ICON_L24_Disk_Latitude       (Epoch_cdf) float32 96B -19.67 ... -18.34
    ICON_L24_Disk_Longitude      (Epoch_cdf) float32 96B 200.5 201.3 ... 217.8
    ICON_L24_Disk_ON2            (Epoch_cdf) float32 96B 0.6418 0.672 ... 0.6956
    ICON_L24_Disk_SZA            (Epoch_cdf) float32 96B 8.413 9.165 ... 25.87
    ICON_L24_Disk_Sigma_ON2      (Epoch_cdf) float32 96B 0.03897 ... 0.05703
    ICON_L24_LBH_Emission        (Epoch_cdf) float32 96B 1.015e+03 ... 900.1
    Epoch                        (record0) int64 56kB 1669248003023 ... 16693...
Attributes: (12/40)
    Acknowledgement:             ['This is a data product from the NASA Ionos...
    ADID_ref:                    ['NASA Contract>NNG12FA45C']
    Calibration_file:            [' ']
    Conventions:                 ['SPDF ISTP/IACG Modified for NetCDF']
    Data_level:                  ['L2.4']
    Data_type:                   ['DP24>Data Product 2.4: FUV Daytime']
    ...                          ...
    Nco:                         ['netCDF Operators version 4.8.1 (Homepage =...
    Nc_kind:                     ['netCDF-4']
    Nc_dimensions_g:             ['Epoch=UNLIMITED', 'Covariance Matrix 2nd D...
    Nc_strings_g:                ['Acknowledgement ADID_Ref Calibration_File ...
    spase_DatasetResourceID:     ['spase://NASA/NumericalData/ICON/FUV/L2/Day...
    DOI:                         ['https://doi.org/10.48322/w3qs-ed95']

Display Metadata

The following code displays metadata for the ICON_L24_Disk_SZA variable, do

print(data.ICON_L24_Disk_SZA)

<xarray.DataArray 'ICON_L24_Disk_SZA' (Epoch_cdf: 24)> Size: 96B
array([ 8.413165,  9.165311,  9.919736, 10.674797, 11.431073, 12.187651,
       12.945468, 13.703261, 14.462048, 15.220608, 15.980153, 16.739532,
       17.499659, 18.259481, 19.019903, 19.780228, 20.540913, 21.30163 ,
       22.062748, 22.823668, 23.585054, 24.345064, 25.106302, 25.867178],
      dtype=float32)
Coordinates:
  * Epoch_cdf  (Epoch_cdf) datetime64[ns] 192B 2022-11-24T23:00:10.767000 ......
Attributes: (12/19)
    FIELDNAM:         Retrieved disk SZA
    NC_DIMENSIONS_V:  Epoch
    NC_DEFLATE:       6
    NC_SHUFFLE:       true
    NC_STORAGE:       chunked
    NC_CHUNKSIZES:    7013
    ...               ...
    VAR_NOTES:        Solar zenith angle corresponding to disk retrieval
    VAR_TYPE:         data
    NC_STRINGS_V:     CatDesc Depend_0 Display_Type FieldNam Long_Name Units ...
    DIM_SIZES:        0
    standard_name:    Retrieved disk SZA
    units:            Degrees

Plot Values

The following code plots the ICON_L24_Disk_SZA variable's values using the label values from the metadata.

data['ICON_L24_Disk_SZA'].plot()

[<matplotlib.lines.Line2D at 0x7fe2861c83a0>]

Additional Documentation

View the cdasws API for additional functions. Additional notebook examples are also available.