grace_input_months

Reads GRACE/GRACE-FO/Swarm files for a specified spherical harmonic degree and order and for a specified date range

Calling Sequence

from gravity_toolkit.grace_input_months import grace_input_months
GRACE_Ylms = grace_input_months(base_dir, PROC, DREL, DSET, LMAX,
  start_mon, end_mon, missing, SLR_C20, DEG1, SLR_C30=SLR_C30)

Source code

gravity_toolkit.grace_input_months(base_dir, PROC, DREL, DSET, LMAX, start_mon, end_mon, missing, SLR_C20, DEG1, **kwargs)[source]

Reads GRACE/GRACE-FO files for a spherical harmonic degree and order and a date range

Can include geocenter values for degree 1 coefficients

Can replace C20 with SLR values for all months

Can replace low-degree harmonics with SLR values for months 179+

Can correct for ECMWF atmospheric “jumps” using GAE/GAF/GAG files [18]

Can correct for Pole Tide drift following Wahr et al. [74]

Parameters:

base_dir: str

Working data directory for GRACE/GRACE-FO data

PROC: str

GRACE/GRACE-FO/Swarm data processing center

'CSR': University of Texas Center for Space Research

'GFZ': German Research Centre for Geosciences (GeoForschungsZentrum)

'JPL': Jet Propulsion Laboratory

'CNES': French Centre National D’Etudes Spatiales

'GRAZ': Institute of Geodesy from GRAZ University of Technology

'COSTG': Combination Service for Time-variable Gravity Fields

'Swarm': Time-variable gravity data from Swarm satellites

DREL: str

GRACE/GRACE-FO/Swarm data release

DSET: str

GRACE/GRACE-FO/Swarm data product

'GAA': non-tidal atmospheric correction

'GAB': non-tidal oceanic correction

'GAC': combined non-tidal atmospheric and oceanic correction

'GAD': ocean bottom pressure product

'GSM': corrected monthly static gravity field product

LMAX: int

Upper bound of Spherical Harmonic Degrees

start_mon: int

starting month to consider in analysis

end_mon: int

ending month to consider in analysis

missing: list

missing months to not consider in analysis

SLR_C20: str

Replaces C20 with SLR values

None: use original values

'CSR': use values from CSR (TN-07, TN-09, TN-11)

'GFZ': use values from GFZ

'GSFC': use values from GSFC (TN-14)

DEG1: str

Use Degree 1 coefficients

None: No degree 1 replacement

'Tellus': TN-13 coefficients from PO.DAAC [58]

'SLR': Satellite laser ranging coefficients from CSR [11]

'UCI': GRACE/GRACE-FO coefficients from [60]

'Swenson': GRACE-derived coefficients from [62]

'GFZ': GFZ GravIS coefficients

MMAX: int or NoneType, default None

Upper bound of Spherical Harmonic Orders

SLR_21: str or NoneType, default ‘’

Replace C21 and S21 with SLR values

None: use original values

'CSR': use values from CSR

'GFZ': use values from GFZ GravIS

'GSFC': use values from GSFC

SLR_22: str or NoneType, default ‘’

Replace C22 and S22 with SLR values

None: use original values

'CSR': use values from CSR

'GSFC': use values from GSFC

SLR_C30: str or NoneType, default ‘’

Replace C30 with SLR values

None: use original values

'CSR': use values from CSR (5x5 with 6,1)

'GFZ': use values from GFZ GravIS

'GSFC': use values from GSFC (TN-14)

SLR_C40: str or NoneType, default ‘’

Replace C40 with SLR values

None: use original values

'CSR': use values from CSR (5x5 with 6,1)

'GSFC': use values from GSFC

SLR_C50: str or NoneType, default ‘’

Replace C50 with SLR values

None: use original values

'CSR': use values from CSR (5x5 with 6,1)

'GSFC': use values from GSFC

POLE_TIDE: bool, default False

Correct GSM data with pole tides following Wahr et al. [74]

ATM: bool, default False

Correct data with ECMWF “jump” corrections following Fagiolini et al. [18]

DEG1_FILE: str or NoneType, default None

full path to degree 1 coefficients file

MODEL_DEG1: bool, default False

least-squares model missing degree 1 coefficients

Returns:

clm: np.ndarray: cosine spherical harmonics to degree/order LMAX and MMAX
slm: np.ndarray: sine spherical harmonics to degree/order LMAX and MMAX
eclm: np.ndarray: uncalibrated cosine spherical harmonic errors
eslm: np.ndarray: uncalibrated sine spherical harmonic errors
time: np.ndarray: time of each measurement (mid-month)
month: np.ndarray: GRACE/GRACE-FO months of input datasets
l: np.ndarray: spherical harmonic degree to LMAX
m: np.ndarray: spherical harmonic order to MMAX
title: str: Processing string denoting low degree zonals replacement, geocenter usage and corrections
directory: str: Directory of exact GRACE/GRACE-FO/Swarm product
attributes: dict: Attributes of input files and corrections

gravity_toolkit.grace_input_months.read_ecmwf_corrections(base_dir, LMAX, months, MMAX=None)[source]

Read atmospheric jump corrections from [18]

Parameters:

base_dir: str: Working data directory for GRACE/GRACE-FO data
LMAX: int: Upper bound of Spherical Harmonic Degrees
months: list: list of GRACE/GRACE-FO months
MMAX: int or NoneType, default None: Upper bound of Spherical Harmonic orders

Returns:

clm: float: atmospheric correction cosine spherical harmonics
slm: float: atmospheric correction sine spherical harmonics
files: list: atmospheric correction files

gravity_toolkit.grace_input_months.regress_model(t_in, d_in, t_out, ORDER=2, CYCLES=None, RELATIVE=0.0)[source]

Calculates a regression model for extrapolating values

Parameters:

t_in: float: input time array
d_in: float: input data array
t_out: float: time array for output regressed values
ORDER: int, default 2: maximum polynomial order for regression model
CYCLES: list or NoneType, default None: list of cyclical terms to include in regression model
RELATIVE: float, default 0.0: relative time for polynomial coefficients in fit

Returns:

d_out: float: output regressed value data array