Gravity

Description: Gridded gravity anomaly data from various sources.

Datasets:

Uieda, Leonardo. “Fatiando a Terra Data: Earth - Gravity Grid at 10 Arc-Minute Resolution.” Zenodo, January 20, 2022. https://doi.org/10.5281/zenodo.5882207.

Förste, Christoph, Sean.L. Bruinsma, Oleg Abrikosov, Jean-Michel Lemoine, Jean Charles Marty, Frank Flechtner, G. Balmino, F. Barthelmes, and R. Biancale. “EIGEN-6C4 The Latest Combined Global Gravity Field Model Including GOCE Data up to Degree and Order 2190 of GFZ Potsdam and GRGS Toulouse.” Application/octet-stream,application/octet-stream,application/zip. GFZ Data Services, 2014. https://doi.org/10.5880/ICGEM.2015.1.

%%capture
%load_ext autoreload
%autoreload 2

import os

from polartoolkit import fetch, maps, utils

os.environ["POLARTOOLKIT_HEMISPHERE"] = "north"

data = fetch.gravity(version="eigen").gravity
data

grdproject [WARNING]: x_inc does not divide 180; geographic boundary condition changed to natural.
grdsample [WARNING]: Output sampling interval in x exceeds input interval and may lead to aliasing.
grdsample [WARNING]: Output sampling interval in y exceeds input interval and may lead to aliasing.

<xarray.DataArray 'gravity' (y: 1401, x: 1401)> Size: 8MB
array([[977685.94, 977689.8 , 977693.5 , ..., 977690.94, 977688.06,
        977685.5 ],
       [977688.75, 977692.7 , 977696.5 , ..., 977693.1 , 977690.2 ,
        977687.56],
       [977690.44, 977694.44, 977698.5 , ..., 977695.6 , 977692.7 ,
        977689.9 ],
       ...,
       [977675.2 , 977678.25, 977681.44, ..., 977651.44, 977648.5 ,
        977644.8 ],
       [977673.  , 977676.1 , 977678.4 , ..., 977649.56, 977646.9 ,
        977643.25],
       [977670.1 , 977673.1 , 977675.5 , ..., 977646.94, 977644.44,
        977641.  ]], shape=(1401, 1401), dtype=float32)
Coordinates:
  * x        (x) float64 11kB -3.5e+06 -3.495e+06 ... 3.495e+06 3.5e+06
  * y        (y) float64 11kB -3.5e+06 -3.495e+06 ... 3.495e+06 3.5e+06
Attributes:
    Conventions:   CF-1.7
    actual_range:  [977641.0, 980201.9375]
    description:
    history:       gmt grdsample @GMTAPI@-S-I-G-M-G-N-000000 -G@GMTAPI@-S-O-G...
    long_name:     z
    title:         

xarray.DataArray

'gravity'

• y: 1401
• x: 1401

• 9.777e+05 9.777e+05 9.777e+05 ... 9.776e+05 9.776e+05 9.776e+05

  array([[977685.94, 977689.8 , 977693.5 , ..., 977690.94, 977688.06,
          977685.5 ],
         [977688.75, 977692.7 , 977696.5 , ..., 977693.1 , 977690.2 ,
          977687.56],
         [977690.44, 977694.44, 977698.5 , ..., 977695.6 , 977692.7 ,
          977689.9 ],
         ...,
         [977675.2 , 977678.25, 977681.44, ..., 977651.44, 977648.5 ,
          977644.8 ],
         [977673.  , 977676.1 , 977678.4 , ..., 977649.56, 977646.9 ,
          977643.25],
         [977670.1 , 977673.1 , 977675.5 , ..., 977646.94, 977644.44,
          977641.  ]], shape=(1401, 1401), dtype=float32)

• Coordinates: (2)
  • x
    (x)
    float64
    -3.5e+06 -3.495e+06 ... 3.5e+06

    actual_range :

    [-3500000.0, 3500000.0]

    axis :

    X

    long_name :

    x

    array([-3500000., -3495000., -3490000., ...,  3490000.,  3495000.,  3500000.],
          shape=(1401,))

  • y
    (y)
    float64
    -3.5e+06 -3.495e+06 ... 3.5e+06

    actual_range :

    [-3500000.0, 3500000.0]

    axis :

    Y

    long_name :

    y

    array([-3500000., -3495000., -3490000., ...,  3490000.,  3495000.,  3500000.],
          shape=(1401,))

• Indexes: (2)
  • x
    PandasIndex

    PandasIndex(Index([-3500000.0, -3495000.0, -3490000.0, -3485000.0, -3480000.0, -3475000.0,
           -3470000.0, -3465000.0, -3460000.0, -3455000.0,
           ...
            3455000.0,  3460000.0,  3465000.0,  3470000.0,  3475000.0,  3480000.0,
            3485000.0,  3490000.0,  3495000.0,  3500000.0],
          dtype='float64', name='x', length=1401))

  • y
    PandasIndex

    PandasIndex(Index([-3500000.0, -3495000.0, -3490000.0, -3485000.0, -3480000.0, -3475000.0,
           -3470000.0, -3465000.0, -3460000.0, -3455000.0,
           ...
            3455000.0,  3460000.0,  3465000.0,  3470000.0,  3475000.0,  3480000.0,
            3485000.0,  3490000.0,  3495000.0,  3500000.0],
          dtype='float64', name='y', length=1401))

• Attributes: (6)

  Conventions :

  CF-1.7

  actual_range :

  [977641.0, 980201.9375]

  description :

  history :

  gmt grdsample @GMTAPI@-S-I-G-M-G-N-000000 -G@GMTAPI@-S-O-G-G-G-Y-000001 -I5000.0 -R-3500000.0/3500000.0/-3500000.0/3500000.0 -Vw

  long_name :

  z

  title :

utils.get_grid_info(data)

(5000.0,
 (-3500000.0, 3500000.0, -3500000.0, 3500000.0),
 977641.0,
 980201.9375,
 'g')

fig = maps.plot_grd(
    data,
    title="EIGEN gravity field",
    cbar_label="mGals",
    coast=True,
    cmap="viridis",
    hist=True,
    cbar_yoffset=1.5,
    robust=True,
    shading=True,
)
fig.show(dpi=200)