units

Class for converting GRACE/GRACE-FO Level-2 data to specific units

Calling Sequence

Calculating the degree dependent factors for converting harmonic units

from gravity_toolkit.units import units
from gravity_toolkit.read_love_numbers import read_love_numbers
hl,kl,ll = read_love_numbers(love_numbers_file, REFERENCE='CF')
dfactor = units(lmax=lmax).harmonic(hl,kl,ll)
to_cmwe = dfactor.cmwe

Calculating the degree dependent factors for converting spatial units

from gravity_toolkit.units import units
from gravity_toolkit.read_love_numbers import read_love_numbers
hl,kl,ll = read_love_numbers(love_numbers_file, REFERENCE='CF')
dfactor = units(lmax=lmax).spatial(hl,kl,ll)
from_cmwe = dfactor.cmwe

Source code

General Attributes and Methods

class gravity_toolkit.units(lmax: int | None = None, a_axis: float = 637813700.0, flat: float = 0.0033528106647474805)[source]

Class for converting spherical harmonic and spatial data to specific units

Parameters:

lmax: int or NoneType, default None: Upper bound of Spherical Harmonic Degrees
a_axis: float, default 6.378137e8: semi-major axis of the Earth’s ellipsoid in cm
flat: float, default 1.0/298.257223563: flattening of the Earth’s ellipsoid

Attributes:

GM: float: Gravitational Constant of the Earth in cm³/s²
g_wmo: float: standard gravitational acceleration in cm/s²
omega: float: Angular velocity of the Earth in radians/s
l: int: spherical harmonic degree up to lmax

property b_axis: float: semi-minor axis of the Earth’s ellipsoid in cm

property rad_e: float: average radius of the Earth in cm with the same volume as the ellipsoid

property rho_e: float: average density of the Earth in g/cm³

property mass: float: approximate mass of the Earth in g

harmonic(hl, kl, ll, **kwargs)[source]

Calculates degree dependent factors for converting spherical harmonic units from [73]

Parameters:

hl: float: Vertical Displacement load Love numbers
kl: float: Gravitational Potential load Love numbers
ll: float: Horizontal Displacement load Love numbers
include_elastic: bool, default True: Include compensation for elastic response
include_ellipsoidal: bool, default False: Include consideration for Earth’s oblateness

Attributes:

norm: float: fully normalized spherical harmonics
cmwe: float: centimeters water equivalent
mmwe: float: millimeters water equivalent
mmGH: float: millimeters geoid height
mmCU: float: millimeters elastic crustal deformation (uplift)
mmCH: float: millimeters elastic crustal deformation (horizontal)
cmVCU: float: centimeters viscoelastic crustal uplift from [76]
mVCU: float: meters viscoelastic crustal uplift from [76]
microGal: float: microGal gravity perturbations
mbar: float: millibar equivalent surface pressure
Pa: float: pascals equivalent surface pressure

spatial(hl, kl, ll, **kwargs)[source]

Calculates degree dependent factors for converting spatial units from [73]

Parameters:

hl: float: Vertical Displacement load Love numbers
kl: float: Gravitational Potential load Love numbers
ll: float: Horizontal Displacement load Love numbers
include_elastic: bool, default True: Include compensation for elastic response

Attributes:

norm: float: fully normalized spherical harmonics
cmwe: float: centimeters water equivalent
mmwe: float: millimeters water equivalent
mmGH: float: millimeters geoid height
microGal: float: microGal gravity perturbations

get(var: str)[source]

Get the degree dependent factors for a specific unit

Parameters:

var: str: Unit name for spherical harmonics or spatial fields

static bycode(var: int) → str[source]

Get the name for a units code

Parameters:

var: int: Named unit code for spherical harmonics or spatial fields

static get_attributes(var: str) → str[source]

Get the variable attributes for a specific unit name

Parameters:

var: tuple: Units and descriptive longname