Vertical Regridding

Authors: Jason Boutte and Jill Zhang

Updated: 11/07/24 [xcdat v0.8.0]

Related APIs:

• xarray.Dataset.regridder.vertical

We’ll cover vertical regridding using xgcm. Two examples are outlined here to apply vertical regridding/remapping using ocean variables and atmosphere variables, respectively.

The data used in this example can be found in the xcdat-data repository.

Notebook Kernel Setup

Users can install their own instance of xcdat and follow these examples using their own environment (e.g., with VS Code, Jupyter, Spyder, iPython) or enable xcdat with existing JupyterHub instances.

First, create the conda environment:

conda create -n xcdat_notebook -c conda-forge xcdat xesmf matplotlib ipython ipykernel cartopy nc-time-axis gsw-xarray jupyter pooch

Then install the kernel from the xcdat_notebook environment using ipykernel and name the kernel with the display name (e.g., xcdat_notebook):

python -m ipykernel install --user --name xcdat_notebook --display-name xcdat_notebook

Then to select the kernel xcdat_notebook in Jupyter to use this kernel.

Example 1: Remapping Ocean Variables

%matplotlib inline

import dask.array as da
import gsw_xarray as gsw
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import xarray as xr
import xcdat as xc

import warnings

warnings.filterwarnings("ignore")

/opt/miniconda3/envs/xcdat_notebook/lib/python3.13/site-packages/esmpy/interface/loadESMF.py:94: VersionWarning: ESMF installation version 8.8.0, ESMPy version 8.8.0b0
  warnings.warn("ESMF installation version {}, ESMPy version {}".format(

# Keys for sea water potential temperature (thetao) and salinity (so) from the NCAR model in CMIP6
keys = ["so_omon_cesm2", "thetao_omon_cesm2"]

ds = xr.merge([xc.tutorial.open_dataset(x) for x in keys])

# lev coordinate is in cm and bounds is in m, convert lev to m
with xr.set_options(keep_attrs=True):
    ds.lev.load()
    ds["lev"] = ds.lev / 100
    ds.lev.attrs["units"] = "meters"

ds = ds.drop_vars(["nlon_bnds"])
ds

2025-03-14 17:03:48,385 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.
2025-03-14 17:03:48,385 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.
2025-03-14 17:03:48,412 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.
2025-03-14 17:03:48,412 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.

<xarray.Dataset> Size: 183MB
Dimensions:    (time: 3, lev: 60, nlat: 384, nlon: 320, d2: 2, vertices: 4)
Coordinates:
    lat        (nlat, nlon) float64 983kB -79.22 -79.22 -79.22 ... 72.19 72.19
  * lev        (lev) float64 480B 5.0 15.0 25.0 ... 5.125e+03 5.375e+03
    lon        (nlat, nlon) float64 983kB 320.6 321.7 322.8 ... 319.4 319.8
  * nlat       (nlat) int32 2kB 1 2 3 4 5 6 7 8 ... 378 379 380 381 382 383 384
  * nlon       (nlon) int32 1kB 1 2 3 4 5 6 7 8 ... 314 315 316 317 318 319 320
  * time       (time) object 24B 1850-01-15 13:00:00.000008 ... 1850-03-15 12...
Dimensions without coordinates: d2, vertices
Data variables:
    so         (time, lev, nlat, nlon) float32 88MB ...
    time_bnds  (time, d2) object 48B 1850-01-01 02:00:00 ... 1850-04-01 00:00:00
    lat_bnds   (nlat, nlon, vertices) float32 2MB -79.49 -79.49 ... 72.41 72.41
    lon_bnds   (nlat, nlon, vertices) float32 2MB 320.0 321.1 ... 320.0 319.6
    lev_bnds   (lev, d2) float32 480B 0.0 10.0 10.0 ... 5.25e+03 5.5e+03
    thetao     (time, lev, nlat, nlon) float32 88MB ...
Attributes: (12/45)
    Conventions:            CF-1.7 CMIP-6.2
    activity_id:            CMIP
    case_id:                15
    cesm_casename:          b.e21.BHIST.f09_g17.CMIP6-historical.001
    contact:                cesm_cmip6@ucar.edu
    creation_date:          2019-01-16T23:15:40Z
    ...                     ...
    sub_experiment:         none
    sub_experiment_id:      none
    branch_time_in_parent:  219000.0
    branch_time_in_child:   674885.0
    branch_method:          standard
    further_info_url:       https://furtherinfo.es-doc.org/CMIP6.NCAR.CESM2.h...

xarray.Dataset

• Dimensions:
  • time: 3
  • lev: 60
  • nlat: 384
  • nlon: 320
  • d2: 2
  • vertices: 4
• Coordinates: (6)
  • lat
    (nlat, nlon)
    float64
    -79.22 -79.22 ... 72.19 72.19

    axis :

    Y

    bounds :

    lat_bnds

    standard_name :

    latitude

    title :

    Latitude

    type :

    double

    units :

    degrees_north

    valid_max :

    90.0

    valid_min :

    -90.0

    array([[-79.22052261, -79.22052261, -79.22052261, ..., -79.22052261,
            -79.22052261, -79.22052261],
           [-78.68630626, -78.68630626, -78.68630626, ..., -78.68630626,
            -78.68630626, -78.68630626],
           [-78.15208992, -78.15208992, -78.15208992, ..., -78.15208992,
            -78.15208992, -78.15208992],
           ...,
           [ 71.29031715,  71.29408252,  71.30160692, ...,  71.30160692,
             71.29408252,  71.29031716],
           [ 71.73524335,  71.73881845,  71.74596231, ...,  71.74596231,
             71.73881845,  71.73524335],
           [ 72.18597561,  72.18933231,  72.19603941, ...,  72.19603941,
             72.18933231,  72.18597562]])

  • lev
    (lev)
    float64
    5.0 15.0 ... 5.125e+03 5.375e+03

    axis :

    Z

    bounds :

    lev_bnds

    positive :

    down

    standard_name :

    olevel

    title :

    ocean model level

    type :

    double

    units :

    meters

    array([5.000000e+00, 1.500000e+01, 2.500000e+01, 3.500000e+01, 4.500000e+01,
           5.500000e+01, 6.500000e+01, 7.500000e+01, 8.500000e+01, 9.500000e+01,
           1.050000e+02, 1.150000e+02, 1.250000e+02, 1.350000e+02, 1.450000e+02,
           1.550000e+02, 1.650984e+02, 1.754790e+02, 1.862913e+02, 1.976603e+02,
           2.097114e+02, 2.225783e+02, 2.364088e+02, 2.513702e+02, 2.676542e+02,
           2.854837e+02, 3.051192e+02, 3.268680e+02, 3.510935e+02, 3.782276e+02,
           4.087846e+02, 4.433777e+02, 4.827367e+02, 5.277280e+02, 5.793729e+02,
           6.388626e+02, 7.075633e+02, 7.870025e+02, 8.788252e+02, 9.847059e+02,
           1.106204e+03, 1.244567e+03, 1.400497e+03, 1.573946e+03, 1.764003e+03,
           1.968944e+03, 2.186457e+03, 2.413972e+03, 2.649001e+03, 2.889385e+03,
           3.133405e+03, 3.379793e+03, 3.627670e+03, 3.876452e+03, 4.125768e+03,
           4.375392e+03, 4.625190e+03, 4.875083e+03, 5.125028e+03, 5.375000e+03])

  • lon
    (nlat, nlon)
    float64
    320.6 321.7 322.8 ... 319.4 319.8

    axis :

    X

    bounds :

    lon_bnds

    standard_name :

    longitude

    title :

    Longitude

    type :

    double

    units :

    degrees_east

    valid_max :

    360.0

    valid_min :

    0.0

    array([[320.56250892, 321.68750895, 322.81250898, ..., 317.18750883,
            318.31250886, 319.43750889],
           [320.56250892, 321.68750895, 322.81250898, ..., 317.18750883,
            318.31250886, 319.43750889],
           [320.56250892, 321.68750895, 322.81250898, ..., 317.18750883,
            318.31250886, 319.43750889],
           ...,
           [320.25133086, 320.75380113, 321.25577325, ..., 318.74424456,
            319.24621668, 319.74869143],
           [320.23459477, 320.70358949, 321.17207442, ..., 318.82794339,
            319.29642832, 319.76542721],
           [320.21650899, 320.6493303 , 321.08163473, ..., 318.91838308,
            319.3506875 , 319.78351267]])

  • nlat
    (nlat)
    int32
    1 2 3 4 5 6 ... 380 381 382 383 384

    long_name :

    cell index along second dimension

    units :

    1

    array([  1,   2,   3, ..., 382, 383, 384], dtype=int32)

  • nlon
    (nlon)
    int32
    1 2 3 4 5 6 ... 316 317 318 319 320

    long_name :

    cell index along first dimension

    units :

    1

    bounds :

    nlon_bnds

    array([  1,   2,   3, ..., 318, 319, 320], dtype=int32)

  • time
    (time)
    object
    1850-01-15 13:00:00.000008 ... 1...

    axis :

    T

    bounds :

    time_bnds

    standard_name :

    time

    title :

    time

    type :

    double

    array([cftime.DatetimeNoLeap(1850, 1, 15, 13, 0, 0, 8, has_year_zero=True),
           cftime.DatetimeNoLeap(1850, 2, 14, 0, 0, 0, 0, has_year_zero=True),
           cftime.DatetimeNoLeap(1850, 3, 15, 12, 0, 0, 0, has_year_zero=True)],
          dtype=object)

• Data variables: (6)
  • so
    (time, lev, nlat, nlon)
    float32
    ...

    cell_measures :

    area: areacello volume: volcello

    cell_methods :

    area: mean where sea time: mean

    comment :

    Sea water salinity is the salt content of sea water, often on the Practical Salinity Scale of 1978. However, the unqualified term 'salinity' is generic and does not necessarily imply any particular method of calculation. The units of salinity are dimensionless and the units attribute should normally be given as 1e-3 or 0.001 i.e. parts per thousand.

    description :

    Sea water salinity is the salt content of sea water, often on the Practical Salinity Scale of 1978. However, the unqualified term 'salinity' is generic and does not necessarily imply any particular method of calculation. The units of salinity are dimensionless and the units attribute should normally be given as 1e-3 or 0.001 i.e. parts per thousand.

    frequency :

    mon

    id :

    so

    long_name :

    Sea Water Salinity

    mipTable :

    Omon

    out_name :

    so

    prov :

    Omon ((isd.003))

    realm :

    ocean

    standard_name :

    sea_water_salinity

    time :

    time

    time_label :

    time-mean

    time_title :

    Temporal mean

    title :

    Sea Water Salinity

    type :

    real

    units :

    0.001

    variable_id :

    so

    [22118400 values with dtype=float32]

  • time_bnds
    (time, d2)
    object
    1850-01-01 02:00:00 ... 1850-04-...

    array([[cftime.DatetimeNoLeap(1850, 1, 1, 2, 0, 0, 0, has_year_zero=True),
            cftime.DatetimeNoLeap(1850, 2, 1, 0, 0, 0, 0, has_year_zero=True)],
           [cftime.DatetimeNoLeap(1850, 2, 1, 0, 0, 0, 0, has_year_zero=True),
            cftime.DatetimeNoLeap(1850, 3, 1, 0, 0, 0, 0, has_year_zero=True)],
           [cftime.DatetimeNoLeap(1850, 3, 1, 0, 0, 0, 0, has_year_zero=True),
            cftime.DatetimeNoLeap(1850, 4, 1, 0, 0, 0, 0, has_year_zero=True)]],
          dtype=object)

  • lat_bnds
    (nlat, nlon, vertices)
    float32
    -79.49 -79.49 ... 72.41 72.41

    array([[[-79.48714, -79.48714, -78.9529 , -78.9529 ],
            [-79.48714, -79.48714, -78.9529 , -78.9529 ],
            [-79.48714, -79.48714, -78.9529 , -78.9529 ],
            ...,
            [-79.48714, -79.48714, -78.9529 , -78.9529 ],
            [-79.48714, -79.48714, -78.9529 , -78.9529 ],
            [-79.48714, -79.48714, -78.9529 , -78.9529 ]],
    
           [[-78.9529 , -78.9529 , -78.41866, -78.41866],
            [-78.9529 , -78.9529 , -78.41866, -78.41866],
            [-78.9529 , -78.9529 , -78.41866, -78.41866],
            ...,
            [-78.9529 , -78.9529 , -78.41866, -78.41866],
            [-78.9529 , -78.9529 , -78.41866, -78.41866],
            [-78.9529 , -78.9529 , -78.41866, -78.41866]],
    
           [[-78.41866, -78.41866, -77.88441, -77.88441],
            [-78.41866, -78.41866, -77.88441, -77.88441],
            [-78.41866, -78.41866, -77.88441, -77.88441],
            ...,
    ...
            ...,
            [ 71.08543,  71.07581,  71.51766,  71.52684],
            [ 71.07581,  71.07003,  71.51215,  71.51766],
            [ 71.07003,  71.0681 ,  71.51031,  71.51215]],
    
           [[ 71.50664,  71.51215,  71.95984,  71.95463],
            [ 71.51215,  71.51766,  71.96504,  71.95984],
            [ 71.51766,  71.52684,  71.97371,  71.96504],
            ...,
            [ 71.52684,  71.51766,  71.96504,  71.97371],
            [ 71.51766,  71.51215,  71.95984,  71.96504],
            [ 71.51215,  71.51031,  71.9581 ,  71.95984]],
    
           [[ 71.95463,  71.95984,  72.41355,  72.4087 ],
            [ 71.95984,  71.96504,  72.41841,  72.41355],
            [ 71.96504,  71.97371,  72.4265 ,  72.41841],
            ...,
            [ 71.97371,  71.96504,  72.41841,  72.4265 ],
            [ 71.96504,  71.95984,  72.41355,  72.41841],
            [ 71.95984,  71.9581 ,  72.41193,  72.41355]]], dtype=float32)

  • lon_bnds
    (nlat, nlon, vertices)
    float32
    320.0 321.1 321.1 ... 320.0 319.6

    array([[[320.    , 321.125 , 321.125 , 320.    ],
            [321.125 , 322.25  , 322.25  , 321.125 ],
            [322.25  , 323.375 , 323.375 , 322.25  ],
            ...,
            [316.625 , 317.75  , 317.75  , 316.625 ],
            [317.75  , 318.875 , 318.875 , 317.75  ],
            [318.875 , 320.    , 320.    , 318.875 ]],
    
           [[320.    , 321.125 , 321.125 , 320.    ],
            [321.125 , 322.25  , 322.25  , 321.125 ],
            [322.25  , 323.375 , 323.375 , 322.25  ],
            ...,
            [316.625 , 317.75  , 317.75  , 316.625 ],
            [317.75  , 318.875 , 318.875 , 317.75  ],
            [318.875 , 320.    , 320.    , 318.875 ]],
    
           [[320.    , 321.125 , 321.125 , 320.    ],
            [321.125 , 322.25  , 322.25  , 321.125 ],
            [322.25  , 323.375 , 323.375 , 322.25  ],
            ...,
    ...
            ...,
            [318.4456, 318.9632, 319.0276, 318.5423],
            [318.9632, 319.4814, 319.5136, 319.0276],
            [319.4814, 320.    , 320.    , 319.5136]],
    
           [[320.0003, 320.4864, 320.4516, 320.0004],
            [320.4864, 320.9724, 320.9029, 320.4516],
            [320.9724, 321.4578, 321.3534, 320.9029],
            ...,
            [318.5423, 319.0276, 319.0972, 318.6466],
            [319.0276, 319.5136, 319.5484, 319.0972],
            [319.5136, 320.    , 320.    , 319.5484]],
    
           [[320.0004, 320.4516, 320.414 , 320.0004],
            [320.4516, 320.9029, 320.8276, 320.414 ],
            [320.9029, 321.3534, 321.2405, 320.8276],
            ...,
            [318.6466, 319.0972, 319.1724, 318.7595],
            [319.0972, 319.5484, 319.586 , 319.1724],
            [319.5484, 320.    , 320.    , 319.586 ]]], dtype=float32)

  • lev_bnds
    (lev, d2)
    float32
    0.0 10.0 10.0 ... 5.25e+03 5.5e+03

    units :

    m

    array([[   0.     ,   10.     ],
           [  10.     ,   20.     ],
           [  20.     ,   30.     ],
           [  30.     ,   40.     ],
           [  40.     ,   50.     ],
           [  50.     ,   60.     ],
           [  60.     ,   70.     ],
           [  70.     ,   80.     ],
           [  80.     ,   90.     ],
           [  90.     ,  100.     ],
           [ 100.     ,  110.     ],
           [ 110.     ,  120.     ],
           [ 120.     ,  130.     ],
           [ 130.     ,  140.     ],
           [ 140.     ,  150.     ],
           [ 150.     ,  160.0492 ],
           [ 160.0492 ,  170.28871],
           [ 170.28871,  180.88516],
           [ 180.88516,  191.97578],
           [ 191.97578,  203.68582],
    ...
           [1045.455  , 1175.3855 ],
           [1175.3855 , 1322.532  ],
           [1322.532  , 1487.2219 ],
           [1487.2219 , 1668.9749 ],
           [1668.9749 , 1866.4738 ],
           [1866.4738 , 2077.7002 ],
           [2077.7002 , 2300.214  ],
           [2300.214  , 2531.4863 ],
           [2531.4863 , 2769.193  ],
           [2769.193  , 3011.3948 ],
           [3011.3948 , 3256.599  ],
           [3256.599  , 3503.732  ],
           [3503.732  , 3752.0613 ],
           [3752.0613 , 4001.11   ],
           [4001.11   , 4250.58   ],
           [4250.58   , 4500.291  ],
           [4500.291  , 4750.1367 ],
           [4750.1367 , 5000.0557 ],
           [5000.0557 , 5250.0137 ],
           [5250.0137 , 5499.9863 ]], dtype=float32)

  • thetao
    (time, lev, nlat, nlon)
    float32
    ...

    cell_measures :

    area: areacello volume: volcello

    cell_methods :

    area: mean where sea time: mean

    comment :

    Diagnostic should be contributed even for models using conservative temperature as prognostic field.

    description :

    Diagnostic should be contributed even for models using conservative temperature as prognostic field.

    frequency :

    mon

    id :

    thetao

    long_name :

    Sea Water Potential Temperature

    mipTable :

    Omon

    out_name :

    thetao

    prov :

    Omon ((isd.003))

    realm :

    ocean

    standard_name :

    sea_water_potential_temperature

    time :

    time

    time_label :

    time-mean

    time_title :

    Temporal mean

    title :

    Sea Water Potential Temperature

    type :

    real

    units :

    degC

    variable_id :

    thetao

    [22118400 values with dtype=float32]

• Indexes: (4)
  • lev
    PandasIndex

    PandasIndex(Index([            5.0,            15.0,            25.0,            35.0,
                      45.0,            55.0,            65.0,            75.0,
                      85.0,            95.0,           105.0,           115.0,
                     125.0,           135.0,           145.0,           155.0,
            165.0983984375, 175.47904296875, 186.29126953125,  197.6602734375,
           209.71138671875,    222.57828125,   236.408828125,    251.37015625,
           267.65419921875, 285.48365234375,    305.11921875, 326.86798828125,
            351.0934765625,  378.2276171875,  408.7846484375,  443.3776953125,
              482.73671875,  527.7280078125,   579.372890625,  638.8626171875,
              707.56328125,        787.0025,   878.825234375,   984.705859375,
             1106.20421875,     1244.566875,    1400.4971875,   1573.94640625,
             1764.00328125,   1968.94421875,    2186.4565625,    2413.9715625,
                2649.00125,    2889.3846875,    3133.4046875,    3379.7934375,
              3627.6703125,     3876.451875,     4125.768125,       4375.3925,
              4625.1903125,    4875.0834375,     5125.028125,          5375.0],
          dtype='float64', name='lev'))

  • nlat
    PandasIndex

    PandasIndex(Index([  1,   2,   3,   4,   5,   6,   7,   8,   9,  10,
           ...
           375, 376, 377, 378, 379, 380, 381, 382, 383, 384],
          dtype='int32', name='nlat', length=384))

  • nlon
    PandasIndex

    PandasIndex(Index([  1,   2,   3,   4,   5,   6,   7,   8,   9,  10,
           ...
           311, 312, 313, 314, 315, 316, 317, 318, 319, 320],
          dtype='int32', name='nlon', length=320))

  • time
    PandasIndex

    PandasIndex(CFTimeIndex([1850-01-15 13:00:00.000008, 1850-02-14 00:00:00, 1850-03-15 12:00:00],
                dtype='object', length=3, calendar='noleap', freq=None))

• Attributes: (45)

  Conventions :

  CF-1.7 CMIP-6.2

  activity_id :

  CMIP

  case_id :

  15

  cesm_casename :

  b.e21.BHIST.f09_g17.CMIP6-historical.001

  contact :

  cesm_cmip6@ucar.edu

  creation_date :

  2019-01-16T23:15:40Z

  data_specs_version :

  01.00.29

  experiment :

  all-forcing simulation of the recent past

  experiment_id :

  historical

  external_variables :

  areacello volcello

  forcing_index :

  1

  frequency :

  mon

  grid :

  native gx1v7 displaced pole grid (384x320 latxlon)

  grid_label :

  gn

  initialization_index :

  1

  institution :

  National Center for Atmospheric Research, Climate and Global Dynamics Laboratory, 1850 Table Mesa Drive, Boulder, CO 80305, USA

  institution_id :

  NCAR

  license :

  CMIP6 model data produced by <The National Center for Atmospheric Research> is licensed under a Creative Commons Attribution-[]ShareAlike 4.0 International License (https://creativecommons.org/licenses/). Consult https://pcmdi.llnl.gov/CMIP6/TermsOfUse for terms of use governing CMIP6 output, including citation requirements and proper acknowledgment. Further information about this data, including some limitations, can be found via the further_info_url (recorded as a global attribute in this file)[]. The data producers and data providers make no warranty, either express or implied, including, but not limited to, warranties of merchantability and fitness for a particular purpose. All liabilities arising from the supply of the information (including any liability arising in negligence) are excluded to the fullest extent permitted by law.

  mip_era :

  CMIP6

  model_doi_url :

  https://doi.org/10.5065/D67H1H0V

  nominal_resolution :

  100 km

  parent_activity_id :

  CMIP

  parent_experiment_id :

  piControl

  parent_mip_era :

  CMIP6

  parent_source_id :

  CESM2

  parent_time_units :

  days since 0001-01-01 00:00:00

  parent_variant_label :

  r1i1p1f1

  physics_index :

  1

  product :

  model-output

  realization_index :

  1

  realm :

  ocean

  source :

  CESM2 (2017): atmosphere: CAM6 (0.9x1.25 finite volume grid; 288 x 192 longitude/latitude; 32 levels; top level 2.25 mb); ocean: POP2 (320x384 longitude/latitude; 60 levels; top grid cell 0-10 m); sea_ice: CICE5.1 (same grid as ocean); land: CLM5 0.9x1.25 finite volume grid; 288 x 192 longitude/latitude; 32 levels; top level 2.25 mb); aerosol: MAM4 (0.9x1.25 finite volume grid; 288 x 192 longitude/latitude; 32 levels; top level 2.25 mb); atmoschem: MAM4 (0.9x1.25 finite volume grid; 288 x 192 longitude/latitude; 32 levels; top level 2.25 mb); landIce: CISM2.1; ocnBgchem: MARBL (320x384 longitude/latitude; 60 levels; top grid cell 0-10 m)

  source_id :

  CESM2

  source_type :

  AOGCM BGC

  table_id :

  Omon

  tracking_id :

  hdl:21.14100/3fc36959-d797-4d0e-a61a-814cb7e04aa3

  variable_id :

  so

  variant_info :

  CMIP6 20th century experiments (1850-2014) with CAM6, interactive land (CLM5), coupled ocean (POP2) with biogeochemistry (MARBL), interactive sea ice (CICE5.1), and non-evolving land ice (CISM2.1)

  variant_label :

  r1i1p1f1

  sub_experiment :

  none

  sub_experiment_id :

  none

  branch_time_in_parent :

  219000.0

  branch_time_in_child :

  674885.0

  branch_method :

  standard

  further_info_url :

  https://furtherinfo.es-doc.org/CMIP6.NCAR.CESM2.historical.none.r1i1p1f1

2. Create the output grid

Related API: xc.create_grid()

In this example, we will generate a vertical grid with a linear spaced level coordinate using xc.create_grid

Alternatively a grid can be loaded from a file, e.g.

grid_urlpath = "http://aims3.llnl.gov/thredds/dodsC/css03_data/CMIP6/CMIP/NOAA-GFDL/GFDL-CM4/abrupt-4xCO2/r1i1p1f1/day/tas/gr2/v20180701/tas_day_GFDL-CM4_abrupt-4xCO2_r1i1p1f1_gr2_00010101-00201231.nc"

grid_ds = xc.open_dataset(grid_urlpath)

output_grid = grid_ds.regridder.grid

output_grid = xc.create_grid(z=xc.create_axis("lev", np.linspace(5, 537, 10)))

output_grid

<xarray.Dataset> Size: 240B
Dimensions:   (lev: 10, bnds: 2)
Coordinates:
  * lev       (lev) float64 80B 5.0 64.11 123.2 182.3 ... 418.8 477.9 537.0
Dimensions without coordinates: bnds
Data variables:
    lev_bnds  (lev, bnds) float64 160B -24.56 34.56 34.56 ... 507.4 507.4 566.6

xarray.Dataset

• Dimensions:
  • lev: 10
  • bnds: 2
• Coordinates: (1)
  • lev
    (lev)
    float64
    5.0 64.11 123.2 ... 477.9 537.0

    axis :

    Z

    coordinate :

    vertical

    bounds :

    lev_bnds

    array([  5.      ,  64.111111, 123.222222, 182.333333, 241.444444, 300.555556,
           359.666667, 418.777778, 477.888889, 537.      ])

• Data variables: (1)
  • lev_bnds
    (lev, bnds)
    float64
    -24.56 34.56 34.56 ... 507.4 566.6

    xcdat_bounds :

    True

    array([[-24.55555556,  34.55555556],
           [ 34.55555556,  93.66666667],
           [ 93.66666667, 152.77777778],
           [152.77777778, 211.88888889],
           [211.88888889, 271.        ],
           [271.        , 330.11111111],
           [330.11111111, 389.22222222],
           [389.22222222, 448.33333333],
           [448.33333333, 507.44444444],
           [507.44444444, 566.55555556]])

• Indexes: (1)
  • lev
    PandasIndex

    PandasIndex(Index([               5.0,  64.11111111111111, 123.22222222222223,
           182.33333333333334, 241.44444444444446, 300.55555555555554,
            359.6666666666667,  418.7777777777778,  477.8888888888889,
                        537.0],
          dtype='float64', name='lev'))

• Attributes: (0)

3. Regridding using the linear method

Related API: xarray.Dataset.regridder.vertical()

Here we will regrid the input data to the output grid using the xgcm tool and the linear method.

We’ll interpolate salinity onto the new vertical grid.

output = ds.regridder.vertical("so", output_grid, tool="xgcm", method="linear")

output.so.isel(time=0).mean(dim="nlon").plot()
plt.gca().invert_yaxis()

2025-03-14 17:03:48,544 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.
2025-03-14 17:03:48,544 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.

4. Regridding from depth to density space

Related API: xarray.Dataset.regridder.vertical()

Here we will regrid the input data to the output grid using the xgcm tool and the linear method.

We’ll remap salinity into density space.

# Apply gsw function to calculate potential density from potential temperature (thetao) and salinity (so)
ds["dens"] = gsw.sigma0(ds.so, ds.thetao)

ds.dens.isel(time=0).mean(dim="nlon").plot()
plt.gca().invert_yaxis()

density_grid = xc.create_grid(z=xc.create_axis("lev", np.linspace(6, 26, 40)))

output = ds.regridder.vertical(
    "so", density_grid, tool="xgcm", method="linear", target_data="dens"
)

output.so.isel(time=0).mean(dim="nlon").plot()
plt.gca().invert_yaxis()

2025-03-14 17:03:50,272 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.
2025-03-14 17:03:50,272 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.

5. Regridding using the conservative method

Related API: xarray.Dataset.regridder.vertical()

Here we will regrid the input data to the output grid using the xgcm tool and the conservative method.

We’ll transform model levels using conservative regridding. In order to perform the regridding we’ll need two grid positions, the lev coordinate is center and we”ll create the outer points using cf_xarray”s bounds_to_vertices.

ds_olev = ds.cf.bounds_to_vertices("lev").rename({"lev_vertices": "olev"})

output = ds_olev.regridder.vertical(
    "so",
    output_grid,
    tool="xgcm",
    method="conservative",
    grid_positions={"center": "lev", "outer": "olev"},
)

output.so.isel(time=0).sel(lev=0, method="nearest").plot()

2025-03-14 17:03:51,436 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.
2025-03-14 17:03:51,436 [WARNING]: bounds.py(add_missing_bounds:194) >> The nlat coord variable has a 'units' attribute that is not in degrees.

<matplotlib.collections.QuadMesh at 0x1773b6e90>

Example 2: Remapping Atmosphere Variables

1. Open dataset

For this example, we are using monthly cloud fraction data and monthly air temperature data from the E3SM-2.0 model.

ds_ta = xc.tutorial.open_dataset("ta_amon_e3sm2", add_bounds=["Z"])
ds_cl = xc.tutorial.open_dataset("cl_amon_e3sm2")

ds_ta

<xarray.Dataset> Size: 15MB
Dimensions:    (time: 3, bnds: 2, plev: 19, lat: 180, lon: 360)
Coordinates:
  * plev       (plev) float64 152B 1e+05 9.25e+04 8.5e+04 ... 1e+03 500.0 100.0
  * lat        (lat) float64 1kB -89.5 -88.5 -87.5 -86.5 ... 86.5 87.5 88.5 89.5
  * lon        (lon) float64 3kB 0.5 1.5 2.5 3.5 4.5 ... 356.5 357.5 358.5 359.5
  * time       (time) object 24B 1850-01-16 12:00:00 ... 1850-03-16 12:00:00
Dimensions without coordinates: bnds
Data variables:
    time_bnds  (time, bnds) object 48B ...
    lat_bnds   (lat, bnds) float64 3kB ...
    lon_bnds   (lon, bnds) float64 6kB ...
    ta         (time, plev, lat, lon) float32 15MB ...
    plev_bnds  (plev, bnds) float64 304B 1.038e+05 9.625e+04 ... 300.0 -100.0
Attributes: (12/49)
    Conventions:                     CF-1.7 CMIP-6.2
    activity_id:                     CMIP
    branch_method:                   standard
    branch_time_in_child:            0.0
    branch_time_in_parent:           36500.0
    creation_date:                   2022-08-31T00:29:52Z
    ...                              ...
    license:                         CMIP6 model data produced by E3SM-Projec...
    cmor_version:                    3.6.1
    tracking_id:                     hdl:21.14100/6e383052-7075-49db-a426-67d...
    version:                         v20220830
    references:                      Golaz, J.-C., L. P. Van Roekel, X. Zheng...
    DODS_EXTRA.Unlimited_Dimension:  time

xarray.Dataset

• Dimensions:
  • time: 3
  • bnds: 2
  • plev: 19
  • lat: 180
  • lon: 360
• Coordinates: (4)
  • plev
    (plev)
    float64
    1e+05 9.25e+04 ... 500.0 100.0

    units :

    Pa

    axis :

    Z

    positive :

    down

    long_name :

    pressure

    standard_name :

    air_pressure

    bounds :

    plev_bnds

    array([100000.,  92500.,  85000.,  70000.,  60000.,  50000.,  40000.,  30000.,
            25000.,  20000.,  15000.,  10000.,   7000.,   5000.,   3000.,   2000.,
             1000.,    500.,    100.])

  • lat
    (lat)
    float64
    -89.5 -88.5 -87.5 ... 88.5 89.5

    bounds :

    lat_bnds

    units :

    degrees_north

    axis :

    Y

    long_name :

    Latitude

    standard_name :

    latitude

    array([-89.5, -88.5, -87.5, -86.5, -85.5, -84.5, -83.5, -82.5, -81.5, -80.5,
           -79.5, -78.5, -77.5, -76.5, -75.5, -74.5, -73.5, -72.5, -71.5, -70.5,
           -69.5, -68.5, -67.5, -66.5, -65.5, -64.5, -63.5, -62.5, -61.5, -60.5,
           -59.5, -58.5, -57.5, -56.5, -55.5, -54.5, -53.5, -52.5, -51.5, -50.5,
           -49.5, -48.5, -47.5, -46.5, -45.5, -44.5, -43.5, -42.5, -41.5, -40.5,
           -39.5, -38.5, -37.5, -36.5, -35.5, -34.5, -33.5, -32.5, -31.5, -30.5,
           -29.5, -28.5, -27.5, -26.5, -25.5, -24.5, -23.5, -22.5, -21.5, -20.5,
           -19.5, -18.5, -17.5, -16.5, -15.5, -14.5, -13.5, -12.5, -11.5, -10.5,
            -9.5,  -8.5,  -7.5,  -6.5,  -5.5,  -4.5,  -3.5,  -2.5,  -1.5,  -0.5,
             0.5,   1.5,   2.5,   3.5,   4.5,   5.5,   6.5,   7.5,   8.5,   9.5,
            10.5,  11.5,  12.5,  13.5,  14.5,  15.5,  16.5,  17.5,  18.5,  19.5,
            20.5,  21.5,  22.5,  23.5,  24.5,  25.5,  26.5,  27.5,  28.5,  29.5,
            30.5,  31.5,  32.5,  33.5,  34.5,  35.5,  36.5,  37.5,  38.5,  39.5,
            40.5,  41.5,  42.5,  43.5,  44.5,  45.5,  46.5,  47.5,  48.5,  49.5,
            50.5,  51.5,  52.5,  53.5,  54.5,  55.5,  56.5,  57.5,  58.5,  59.5,
            60.5,  61.5,  62.5,  63.5,  64.5,  65.5,  66.5,  67.5,  68.5,  69.5,
            70.5,  71.5,  72.5,  73.5,  74.5,  75.5,  76.5,  77.5,  78.5,  79.5,
            80.5,  81.5,  82.5,  83.5,  84.5,  85.5,  86.5,  87.5,  88.5,  89.5])

  • lon
    (lon)
    float64
    0.5 1.5 2.5 ... 357.5 358.5 359.5

    bounds :

    lon_bnds

    units :

    degrees_east

    axis :

    X

    long_name :

    Longitude

    standard_name :

    longitude

    array([  0.5,   1.5,   2.5, ..., 357.5, 358.5, 359.5])

  • time
    (time)
    object
    1850-01-16 12:00:00 ... 1850-03-...

    bounds :

    time_bnds

    axis :

    T

    long_name :

    time

    standard_name :

    time

    _ChunkSizes :

    1

    array([cftime.DatetimeNoLeap(1850, 1, 16, 12, 0, 0, 0, has_year_zero=True),
           cftime.DatetimeNoLeap(1850, 2, 15, 0, 0, 0, 0, has_year_zero=True),
           cftime.DatetimeNoLeap(1850, 3, 16, 12, 0, 0, 0, has_year_zero=True)],
          dtype=object)

• Data variables: (5)
  • time_bnds
    (time, bnds)
    object
    ...

    _ChunkSizes :

    [1 2]

    [6 values with dtype=object]

  • lat_bnds
    (lat, bnds)
    float64
    ...

    _ChunkSizes :

    [180 2]

    [360 values with dtype=float64]

  • lon_bnds
    (lon, bnds)
    float64
    ...

    _ChunkSizes :

    [360 2]

    [720 values with dtype=float64]

  • ta
    (time, plev, lat, lon)
    float32
    ...

    standard_name :

    air_temperature

    long_name :

    Air Temperature

    comment :

    Air Temperature

    units :

    K

    cell_methods :

    time: mean

    cell_measures :

    area: areacella

    _ChunkSizes :

    [ 1 19 180 360]

    [3693600 values with dtype=float32]

  • plev_bnds
    (plev, bnds)
    float64
    1.038e+05 9.625e+04 ... -100.0

    xcdat_bounds :

    True

    array([[ 1.0375e+05,  9.6250e+04],
           [ 9.6250e+04,  8.8750e+04],
           [ 8.8750e+04,  7.7500e+04],
           [ 7.7500e+04,  6.5000e+04],
           [ 6.5000e+04,  5.5000e+04],
           [ 5.5000e+04,  4.5000e+04],
           [ 4.5000e+04,  3.5000e+04],
           [ 3.5000e+04,  2.7500e+04],
           [ 2.7500e+04,  2.2500e+04],
           [ 2.2500e+04,  1.7500e+04],
           [ 1.7500e+04,  1.2500e+04],
           [ 1.2500e+04,  8.5000e+03],
           [ 8.5000e+03,  6.0000e+03],
           [ 6.0000e+03,  4.0000e+03],
           [ 4.0000e+03,  2.5000e+03],
           [ 2.5000e+03,  1.5000e+03],
           [ 1.5000e+03,  7.5000e+02],
           [ 7.5000e+02,  3.0000e+02],
           [ 3.0000e+02, -1.0000e+02]])

• Indexes: (4)
  • plev
    PandasIndex

    PandasIndex(Index([100000.0,  92500.0,  85000.0,  70000.0,  60000.0,  50000.0,  40000.0,
            30000.0,  25000.0,  20000.0,  15000.0,  10000.0,   7000.0,   5000.0,
             3000.0,   2000.0,   1000.0,    500.0,    100.0],
          dtype='float64', name='plev'))

  • lat
    PandasIndex

    PandasIndex(Index([-89.5, -88.5, -87.5, -86.5, -85.5, -84.5, -83.5, -82.5, -81.5, -80.5,
           ...
            80.5,  81.5,  82.5,  83.5,  84.5,  85.5,  86.5,  87.5,  88.5,  89.5],
          dtype='float64', name='lat', length=180))

  • lon
    PandasIndex

    PandasIndex(Index([  0.5,   1.5,   2.5,   3.5,   4.5,   5.5,   6.5,   7.5,   8.5,   9.5,
           ...
           350.5, 351.5, 352.5, 353.5, 354.5, 355.5, 356.5, 357.5, 358.5, 359.5],
          dtype='float64', name='lon', length=360))

  • time
    PandasIndex

    PandasIndex(CFTimeIndex([1850-01-16 12:00:00, 1850-02-15 00:00:00, 1850-03-16 12:00:00],
                dtype='object', length=3, calendar='noleap', freq='708h'))

• Attributes: (49)

  Conventions :

  CF-1.7 CMIP-6.2

  activity_id :

  CMIP

  branch_method :

  standard

  branch_time_in_child :

  0.0

  branch_time_in_parent :

  36500.0

  creation_date :

  2022-08-31T00:29:52Z

  data_contact :

  E3SM-DATA-SUPPORT@LLNL.GOV

  data_specs_version :

  01.00.33

  experiment :

  all-forcing simulation of the recent past

  experiment_id :

  historical

  external_variables :

  areacella

  forcing_index :

  1

  frequency :

  mon

  further_info_url :

  https://furtherinfo.es-doc.org/CMIP6.E3SM-Project.E3SM-2-0.historical.none.r1i1p1f1

  grid :

  data regridded to a CMIP6 standard 1x1 degree lonxlat grid from the native grid using an area-average preserving method.

  grid_label :

  gr

  history :

  2022-08-31T00:29:52Z ;rewrote data to be consistent with CMIP for variable ta found in table Amon.; v2.LR.historical_0101

  initialization_index :

  1

  institution :

  LLNL (Lawrence Livermore National Laboratory, Livermore, CA 94550, USA); ANL (Argonne National Laboratory, Argonne, IL 60439, USA); BNL (Brookhaven National Laboratory, Upton, NY 11973, USA); LANL (Los Alamos National Laboratory, Los Alamos, NM 87545, USA); LBNL (Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA); ORNL (Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA); PNNL (Pacific Northwest National Laboratory, Richland, WA 99352, USA); SNL (Sandia National Laboratories, Albuquerque, NM 87185, USA). Mailing address: LLNL Climate Program, c/o David C. Bader, Principal Investigator, L-103, 7000 East Avenue, Livermore, CA 94550, USA

  institution_id :

  E3SM-Project

  mip_era :

  CMIP6

  nominal_resolution :

  100 km

  parent_activity_id :

  CMIP

  parent_experiment_id :

  piControl

  parent_mip_era :

  CMIP6

  parent_source_id :

  E3SM-2-0

  parent_time_units :

  days since 0001-01-01

  parent_variant_label :

  r1i1p1f1

  physics_index :

  1

  product :

  model-output

  project_PI :

  Dave Bader (bader2@llnl.gov)

  realization_index :

  1

  realm :

  atmos

  source :

  E3SM 2.0 (2022): aerosol: MAM4 with new resuspension, marine organics, secondary organics, and dust (atmos grid) atmos: EAM (v2.0, cubed sphere spectral-element grid; 5400 elements, 30x30 per cube face. Dynamics: degree 3 (p=3) polynomials within each spectral element, 112 km average resolution. Physics: 2x2 finite volume cells within each spectral element, 1.5 degree (168 km) average grid spacing; 72 vertical layers; top level 60 km) atmosChem: Troposphere specified oxidants (except passive ozone with the lower boundary sink) for aerosols. Stratosphere linearized interactive ozone (LINOZ v2) (atmos grid) land: ELM (v1.0, satellite phenology mode, atmos grid), MOSART (v1.0, 0.5 degree latitude/longitude) landIce: none ocean: MPAS-Ocean (E3SMv2.0, EC30to60E2r2 unstructured SVTs mesh with 236853 cells, 719506 edges, variable resolution 60 to 30 km; 60 levels; top grid cell 0-10 m) ocnBgchem: none seaIce: MPAS-Seaice (E3SMv2.0, ocean grid; 5 ice categories; 7 ice, 5 snow layers)

  source_id :

  E3SM-2-0

  source_type :

  AOGCM AER

  sub_experiment :

  none

  sub_experiment_id :

  none

  table_id :

  Amon

  table_info :

  Creation Date:(18 November 2020) MD5:926d66e1a62ce074375d24e09d01cc11

  title :

  E3SM-2-0 output prepared for CMIP6

  variable_id :

  ta

  variant_label :

  r1i1p1f1

  license :

  CMIP6 model data produced by E3SM-Project is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). Consult https://pcmdi.llnl.gov/CMIP6/TermsOfUse for terms of use governing CMIP6 output, including citation requirements and proper acknowledgment. Further information about this data, including some limitations, can be found via the further_info_url (recorded as a global attribute in this file) and at https://pcmdi.llnl.gov/. The data producers and data providers make no warranty, either express or implied, including, but not limited to, warranties of merchantability and fitness for a particular purpose. All liabilities arising from the supply of the information (including any liability arising in negligence) are excluded to the fullest extent permitted by law.

  cmor_version :

  3.6.1

  tracking_id :

  hdl:21.14100/6e383052-7075-49db-a426-67d8943382d6

  version :

  v20220830

  references :

  Golaz, J.-C., L. P. Van Roekel, X. Zheng and co-authors, 2022: The DOE E3SM Model Version 2: Overview of the physical model and initial model evaluation. JAMES, doi: 10.1029/2022MS003156; http://e3sm.org

  DODS_EXTRA.Unlimited_Dimension :

  time

2. Create the output grid

Related API: xc.create_grid()

In this example, we will generate a grid with a linear spaced level coordinate.

output_grid = xc.create_grid(z=xc.create_axis("lev", np.linspace(100000, 1, 13)))

output_grid

<xarray.Dataset> Size: 312B
Dimensions:   (lev: 13, bnds: 2)
Coordinates:
  * lev       (lev) float64 104B 1e+05 9.167e+04 8.333e+04 ... 8.334e+03 1.0
Dimensions without coordinates: bnds
Data variables:
    lev_bnds  (lev, bnds) float64 208B 1.042e+05 9.583e+04 ... -4.166e+03

xarray.Dataset

• Dimensions:
  • lev: 13
  • bnds: 2
• Coordinates: (1)
  • lev
    (lev)
    float64
    1e+05 9.167e+04 ... 8.334e+03 1.0

    axis :

    Z

    coordinate :

    vertical

    bounds :

    lev_bnds

    array([1.000000e+05, 9.166675e+04, 8.333350e+04, 7.500025e+04, 6.666700e+04,
           5.833375e+04, 5.000050e+04, 4.166725e+04, 3.333400e+04, 2.500075e+04,
           1.666750e+04, 8.334250e+03, 1.000000e+00])

• Data variables: (1)
  • lev_bnds
    (lev, bnds)
    float64
    1.042e+05 9.583e+04 ... -4.166e+03

    xcdat_bounds :

    True

    array([[104166.625,  95833.375],
           [ 95833.375,  87500.125],
           [ 87500.125,  79166.875],
           [ 79166.875,  70833.625],
           [ 70833.625,  62500.375],
           [ 62500.375,  54167.125],
           [ 54167.125,  45833.875],
           [ 45833.875,  37500.625],
           [ 37500.625,  29167.375],
           [ 29167.375,  20834.125],
           [ 20834.125,  12500.875],
           [ 12500.875,   4167.625],
           [  4167.625,  -4165.625]])

• Indexes: (1)
  • lev
    PandasIndex

    PandasIndex(Index([100000.0, 91666.75,  83333.5, 75000.25,  66667.0, 58333.75,  50000.5,
           41667.25,  33334.0, 25000.75,  16667.5,  8334.25,      1.0],
          dtype='float64', name='lev'))

• Attributes: (0)

3. Remapping air temperature on pressure levels to a set of target pressure levels.

Related API: xarray.Dataset.regridder.vertical()

Here we will regrid the input data to the output grid using the xgcm tool and the log method.

We’ll remap pressure levels.

# Remap from original pressure level to target pressure level using logarithmic interpolation
# Note: output grids can be either ascending or descending
output_ta = ds_ta.regridder.vertical("ta", output_grid, method="log")

output_ta.ta.isel(time=0, lev=0).plot()

<matplotlib.collections.QuadMesh at 0x175eab250>

4: Remap cloud fraction from model hybrid coordinate to pressure levels

Related API: xarray.Dataset.regridder.vertical()

Here we will regrid the input data to the output grid using the xgcm tool and the linear method.

We’ll remap cloud fraction into pressure space.

# Build hybrid pressure coordinate
def hybrid_coordinate(p0, a, b, ps, **kwargs):
    return a * p0 + b * ps


pressure = hybrid_coordinate(**ds_cl.data_vars)

pressure

<xarray.DataArray (lev: 72, time: 3, lat: 180, lon: 360)> Size: 112MB
array([[[[6.85818450e+04, 6.85818450e+04, 6.85818450e+04, ...,
          7.05259253e+04, 7.05259253e+04, 7.05259253e+04],
         [6.92225598e+04, 6.92220606e+04, 6.92210543e+04, ...,
          7.13934393e+04, 7.13948044e+04, 7.13954831e+04],
         [6.96804641e+04, 6.96804641e+04, 6.96804641e+04, ...,
          7.20169379e+04, 7.20169379e+04, 7.20169379e+04],
         ...,
         [1.01909534e+05, 1.01909534e+05, 1.01909534e+05, ...,
          1.01960629e+05, 1.01960629e+05, 1.01960629e+05],
         [1.01971028e+05, 1.01971098e+05, 1.01971230e+05, ...,
          1.02018331e+05, 1.02018207e+05, 1.02018144e+05],
         [1.02057070e+05, 1.02057070e+05, 1.02057070e+05, ...,
          1.02098617e+05, 1.02098617e+05, 1.02098617e+05]],

        [[6.85818450e+04, 6.85818450e+04, 6.85818450e+04, ...,
          7.05259253e+04, 7.05259253e+04, 7.05259253e+04],
         [6.92225598e+04, 6.92220606e+04, 6.92210543e+04, ...,
          7.13934393e+04, 7.13948044e+04, 7.13954831e+04],
         [6.96804641e+04, 6.96804641e+04, 6.96804641e+04, ...,
          7.20169379e+04, 7.20169379e+04, 7.20169379e+04],
...
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01]],

        [[1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
         ...,
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
         [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
          1.23825413e+01, 1.23825413e+01, 1.23825413e+01]]]])
Coordinates:
  * lev      (lev) float64 576B 0.9985 0.9938 0.9862 ... 0.0001828 0.0001238
  * lat      (lat) float64 1kB -89.5 -88.5 -87.5 -86.5 ... 86.5 87.5 88.5 89.5
  * lon      (lon) float64 3kB 0.5 1.5 2.5 3.5 4.5 ... 356.5 357.5 358.5 359.5
  * time     (time) object 24B 1850-01-16 12:00:00 ... 1850-03-16 12:00:00

xarray.DataArray

• lev: 72
• time: 3
• lat: 180
• lon: 360

• 6.858e+04 6.858e+04 6.858e+04 6.858e+04 ... 12.38 12.38 12.38 12.38

  array([[[[6.85818450e+04, 6.85818450e+04, 6.85818450e+04, ...,
            7.05259253e+04, 7.05259253e+04, 7.05259253e+04],
           [6.92225598e+04, 6.92220606e+04, 6.92210543e+04, ...,
            7.13934393e+04, 7.13948044e+04, 7.13954831e+04],
           [6.96804641e+04, 6.96804641e+04, 6.96804641e+04, ...,
            7.20169379e+04, 7.20169379e+04, 7.20169379e+04],
           ...,
           [1.01909534e+05, 1.01909534e+05, 1.01909534e+05, ...,
            1.01960629e+05, 1.01960629e+05, 1.01960629e+05],
           [1.01971028e+05, 1.01971098e+05, 1.01971230e+05, ...,
            1.02018331e+05, 1.02018207e+05, 1.02018144e+05],
           [1.02057070e+05, 1.02057070e+05, 1.02057070e+05, ...,
            1.02098617e+05, 1.02098617e+05, 1.02098617e+05]],
  
          [[6.85818450e+04, 6.85818450e+04, 6.85818450e+04, ...,
            7.05259253e+04, 7.05259253e+04, 7.05259253e+04],
           [6.92225598e+04, 6.92220606e+04, 6.92210543e+04, ...,
            7.13934393e+04, 7.13948044e+04, 7.13954831e+04],
           [6.96804641e+04, 6.96804641e+04, 6.96804641e+04, ...,
            7.20169379e+04, 7.20169379e+04, 7.20169379e+04],
  ...
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01]],
  
          [[1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
           ...,
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01],
           [1.23825413e+01, 1.23825413e+01, 1.23825413e+01, ...,
            1.23825413e+01, 1.23825413e+01, 1.23825413e+01]]]])

• Coordinates: (4)
  • lev
    (lev)
    float64
    0.9985 0.9938 ... 0.0001238

    bounds :

    lev_bnds

    units :

    1

    axis :

    Z

    positive :

    down

    long_name :

    hybrid sigma pressure coordinate

    standard_name :

    atmosphere_hybrid_sigma_pressure_coordinate

    formula :

    p = a*p0 + b*ps

    formula_terms :

    p0: p0 a: a b: b ps: ps

    array([9.984964e-01, 9.937570e-01, 9.862053e-01, 9.773141e-01, 9.679111e-01,
           9.580128e-01, 9.476362e-01, 9.367990e-01, 9.255197e-01, 9.138175e-01,
           9.017118e-01, 8.892227e-01, 8.763706e-01, 8.631764e-01, 8.496612e-01,
           8.350952e-01, 8.178688e-01, 7.969527e-01, 7.723628e-01, 7.444748e-01,
           7.137046e-01, 6.804980e-01, 6.453200e-01, 6.086438e-01, 5.706249e-01,
           5.316395e-01, 4.924686e-01, 4.543958e-01, 4.188035e-01, 3.859990e-01,
           3.557641e-01, 3.278975e-01, 3.022136e-01, 2.785416e-01, 2.567237e-01,
           2.366148e-01, 2.180810e-01, 2.009989e-01, 1.852549e-01, 1.707441e-01,
           1.573699e-01, 1.450433e-01, 1.336822e-01, 1.232110e-01, 1.135600e-01,
           1.046650e-01, 9.646667e-02, 8.891054e-02, 8.194628e-02, 7.535534e-02,
           6.847639e-02, 6.101518e-02, 5.330956e-02, 4.567120e-02, 3.836628e-02,
           3.159325e-02, 2.544470e-02, 1.999634e-02, 1.533394e-02, 1.147379e-02,
           8.377404e-03, 5.968449e-03, 4.129833e-03, 2.797027e-03, 1.894352e-03,
           1.282995e-03, 8.689386e-04, 5.885091e-04, 3.985817e-04, 2.699489e-04,
           1.828292e-04, 1.238254e-04])

  • lat
    (lat)
    float64
    -89.5 -88.5 -87.5 ... 88.5 89.5

    bounds :

    lat_bnds

    units :

    degrees_north

    axis :

    Y

    long_name :

    Latitude

    standard_name :

    latitude

    array([-89.5, -88.5, -87.5, -86.5, -85.5, -84.5, -83.5, -82.5, -81.5, -80.5,
           -79.5, -78.5, -77.5, -76.5, -75.5, -74.5, -73.5, -72.5, -71.5, -70.5,
           -69.5, -68.5, -67.5, -66.5, -65.5, -64.5, -63.5, -62.5, -61.5, -60.5,
           -59.5, -58.5, -57.5, -56.5, -55.5, -54.5, -53.5, -52.5, -51.5, -50.5,
           -49.5, -48.5, -47.5, -46.5, -45.5, -44.5, -43.5, -42.5, -41.5, -40.5,
           -39.5, -38.5, -37.5, -36.5, -35.5, -34.5, -33.5, -32.5, -31.5, -30.5,
           -29.5, -28.5, -27.5, -26.5, -25.5, -24.5, -23.5, -22.5, -21.5, -20.5,
           -19.5, -18.5, -17.5, -16.5, -15.5, -14.5, -13.5, -12.5, -11.5, -10.5,
            -9.5,  -8.5,  -7.5,  -6.5,  -5.5,  -4.5,  -3.5,  -2.5,  -1.5,  -0.5,
             0.5,   1.5,   2.5,   3.5,   4.5,   5.5,   6.5,   7.5,   8.5,   9.5,
            10.5,  11.5,  12.5,  13.5,  14.5,  15.5,  16.5,  17.5,  18.5,  19.5,
            20.5,  21.5,  22.5,  23.5,  24.5,  25.5,  26.5,  27.5,  28.5,  29.5,
            30.5,  31.5,  32.5,  33.5,  34.5,  35.5,  36.5,  37.5,  38.5,  39.5,
            40.5,  41.5,  42.5,  43.5,  44.5,  45.5,  46.5,  47.5,  48.5,  49.5,
            50.5,  51.5,  52.5,  53.5,  54.5,  55.5,  56.5,  57.5,  58.5,  59.5,
            60.5,  61.5,  62.5,  63.5,  64.5,  65.5,  66.5,  67.5,  68.5,  69.5,
            70.5,  71.5,  72.5,  73.5,  74.5,  75.5,  76.5,  77.5,  78.5,  79.5,
            80.5,  81.5,  82.5,  83.5,  84.5,  85.5,  86.5,  87.5,  88.5,  89.5])

  • lon
    (lon)
    float64
    0.5 1.5 2.5 ... 357.5 358.5 359.5

    bounds :

    lon_bnds

    units :

    degrees_east

    axis :

    X

    long_name :

    Longitude

    standard_name :

    longitude

    array([  0.5,   1.5,   2.5, ..., 357.5, 358.5, 359.5])

  • time
    (time)
    object
    1850-01-16 12:00:00 ... 1850-03-...

    bounds :

    time_bnds

    axis :

    T

    long_name :

    time

    standard_name :

    time

    _ChunkSizes :

    1

    array([cftime.DatetimeNoLeap(1850, 1, 16, 12, 0, 0, 0, has_year_zero=True),
           cftime.DatetimeNoLeap(1850, 2, 15, 0, 0, 0, 0, has_year_zero=True),
           cftime.DatetimeNoLeap(1850, 3, 16, 12, 0, 0, 0, has_year_zero=True)],
          dtype=object)

• Indexes: (4)
  • lev
    PandasIndex

    PandasIndex(Index([    0.9984964394917621,     0.9937569563042221,     0.9862053331610676,
                0.977314063869485,     0.9679110804007753,     0.9580127663713389,
               0.9476361588543765,     0.9367989948227038,      0.925519748147335,
                0.913817504420407,     0.9017118332902198,     0.8892227360962712,
               0.8763706483341046,       0.86317642564934,     0.8496612491105949,
               0.8350951708866112,     0.8178688234772361,      0.796952749718736,
               0.7723628379433543,     0.7444748293231951,     0.7137046383204335,
               0.6804980444382399,     0.6453199679615715,     0.6086437744215841,
               0.5706249031033329,      0.531639531357463,    0.49246857402252703,
               0.4543958139891781,     0.4188034628792632,     0.3859990239199109,
              0.35576412943838015,    0.32789750608917023,     0.3022136401218828,
               0.2785415583098347,     0.2567236859052588,    0.23661478658749036,
              0.21808099703300082,    0.20099893987110398,    0.18525490222915122,
              0.17074407952158202,    0.15736987784007928,    0.14504326553270042,
               0.1336821799321061,      0.123210991427466,    0.11356000142146327,
              0.10466496728675462,    0.09646667344493705,    0.08891054314956091,
              0.08194627512473471,    0.07535533589726098,    0.06847639022971255,
             0.061015181670369456,   0.053309561434392534,   0.045671197939426804,
              0.03836628309442701,    0.03159325129128525,   0.025444696509961597,
             0.019996337978167075,   0.015333938222216858,   0.011473787230534558,
              0.00837740437894177,   0.005968449367118077,   0.004129833155024836,
            0.0027970269352932593,  0.0018943524794063876,   0.001282994908254925,
            0.0008689385700405001,   0.000588509146564753, 0.00039858170362288225,
           0.00026994886212093746, 0.00018282923550684864, 0.00012382541305561677],
          dtype='float64', name='lev'))

  • lat
    PandasIndex

    PandasIndex(Index([-89.5, -88.5, -87.5, -86.5, -85.5, -84.5, -83.5, -82.5, -81.5, -80.5,
           ...
            80.5,  81.5,  82.5,  83.5,  84.5,  85.5,  86.5,  87.5,  88.5,  89.5],
          dtype='float64', name='lat', length=180))

  • lon
    PandasIndex

    PandasIndex(Index([  0.5,   1.5,   2.5,   3.5,   4.5,   5.5,   6.5,   7.5,   8.5,   9.5,
           ...
           350.5, 351.5, 352.5, 353.5, 354.5, 355.5, 356.5, 357.5, 358.5, 359.5],
          dtype='float64', name='lon', length=360))

  • time
    PandasIndex

    PandasIndex(CFTimeIndex([1850-01-16 12:00:00, 1850-02-15 00:00:00, 1850-03-16 12:00:00],
                dtype='object', length=3, calendar='noleap', freq='708h'))

• Attributes: (0)

new_pressure_grid = xc.create_grid(
    z=xc.create_axis("lev", np.linspace(100000, 1, 13))
)

output_cl = ds_cl.regridder.vertical(
    "cl", new_pressure_grid, method="linear", target_data=pressure
)

output_cl.cl.isel(time=0, lev=0).plot()

<matplotlib.collections.QuadMesh at 0x17f0f9e50>

output_cl.cl.isel(time=0).mean(dim="lon").plot()
plt.gca().invert_yaxis()