read-GRACE-geocenter

Reads geocenter data from Sutterley et al. (2019) for updating Level-2 spherical harmonic data from the NASA/DLR Gravity Recovery and Climate Experiment (GRACE) and the NASA/GFZ Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) missions

• Figshare Data Repository
• NASA GRACE mission site
• JPL GRACE Tellus site
• JPL GRACE-FO site
• UTCSR GRACE site

Calling Sequence

from read_GRACE_geocenter import read_GRACE_geocenter
CSR_input = read_GRACE_geocenter('CSR_RL06_MPIOM_SLF_iter.txt')

Inputs

• full path to input geocenter file

Outputs

• C10: cosine spherical harmonics of degree one and order zero (Z-component)
• C11: cosine spherical harmonics of degree one and order one (X-component)
• S11: sine spherical harmonics of degree one and order one (Y-component)
• time: mid-month date in year-decimal
• JD: mid-month date as Julian day
• month: GRACE month of data
• header: text header of the geocenter file (will parse YAML headers)

Dependencies

• numpy: Scientific Computing Tools For Python
• PyYAML: YAML parser and emitter for Python

Data Description

• Release-5 Geocenter Coefficients: Derived from GRACE mission measurements and OMCT ocean model outputs. Represents the largest-scale variability of hydrologic, cryospheric, and solid Earth processes as well as the atmospheric and oceanic processes not captured in the GRACE RL05 de-aliasing product. Glacial Isostatic Adjustment (GIA) estimates from A et al. (2013) have been restored. ECMWF corrections from Fagiolini et al. (2015) have been restored.

• Release-5 Geocenter Coefficients with Atmospheric and Oceanic Variability: Derived from GRACE mission measurements and OMCT ocean model outputs. Represents the largest-scale variability of atmospheric, oceanic, hydrologic, cryospheric, and solid Earth processes. Glacial Isostatic Adjustment (GIA) estimates from A et al. (2013) have been restored. Monthly estimates of atmospheric and oceanic variability from the GRACE RL05 de-aliasing product (GAC) have been restored.

• Release-6 Geocenter Coefficients: Derived from GRACE mission measurements and MPIOM ocean model outputs. Represents the largest-scale variability of hydrologic, cryospheric, and solid Earth processes as well as the atmospheric and oceanic processes not captured in the GRACE RL06 de-aliasing product. Glacial Isostatic Adjustment (GIA) estimates from A et al. (2013) have been restored.

• Release-6 Geocenter Coefficients with Atmospheric and Oceanic Variability: Derived from GRACE mission measurements and MPIOM ocean model outputs. Represents the largest-scale variability of atmospheric, oceanic, hydrologic, cryospheric, and solid Earth processes. Glacial Isostatic Adjustment (GIA) estimates from A et al. (2013) have been restored. Monthly estimates of atmospheric and oceanic variability from the GRACE RL06 de-aliasing product (GAC) have been restored.

References

T. C. Sutterley, and I. Velicogna, "Improved estimates of geocenter variability from time-variable gravity and ocean model outputs", Remote Sensing, 11(18), 2108, (2019). doi:10.3390/rs11182108

S. C. Swenson, D. P. Chambers, and J. Wahr, "Estimating geocenter variations from a combination of GRACE and ocean model output", Journal of Geophysical Research: Solid Earth, 113(B08410), (2008). doi:10.1029/2007JB005338

G. A, J. Wahr, and S. Zhong, "Computations of the viscoelastic response of a 3-D compressible Earth to surface loading: an application to Glacial Isostatic Adjustment in Antarctica and Canada", Geophysical Journal International, 192(2), 557-572, (2013). doi:10.1093/gji/ggs030

E. Fagiolini, F. Flechtner, M. Horwath, H. Dobslaw, "Correction of inconsistencies in ECMWF's operational analysis data during de-aliasing of GRACE gravity models", Geophysical Journal International, 202(3), 2150, (2015). doi:10.1093/gji/ggv276

Data Repository

T. C. Sutterley and I. Velicogna, "Geocenter Estimates from Time-Variable Gravity and Ocean Model Outputs", (2019). doi:10.6084/m9.figshare.7388540

Download

The program homepage is:
https://github.com/tsutterley/read-GRACE-geocenter
A zip archive of the latest version is available directly at:
https://github.com/tsutterley/read-GRACE-geocenter/archive/main.zip

Disclaimer

This project contains work and contributions from the scientific community This program is not sponsored or maintained by the Universities Space Research Association (USRA) or NASA. It is provided here for your convenience but with no guarantees whatsoever.

License

The content of this project is licensed under the Creative Commons Attribution 4.0 Attribution license and the source code is licensed under the MIT license.