Combined monthly gravity fields of the GRACE satellite mission in spherical harmonic representation (Level-2 product) generated by the Combination Service for Time-variable Gravity Fields (COST-G; Jäggi et al. (2020):http://dx.doi.org/10.1007/1345_2020_109), a product center for time-variable gravity fields of IAG's International Gravity Field Service (IGFS). COST-G GRACE RL01 is a combination of AIUB-RL02, GFZ-RL06, GRGS-RL04 (unconstrained solution), ITSG-GRACE2018, and CSR-RL06. The original time-series were provided by the analysis centers (ACs) and partner analysis centers (PCs) of COST-G.

COST-G performs a harmonization and quality control of the individual input solutions of the COST-G ACs and PCs. The combination of COST-G GRACE RL01 is then performed applying variance component estimation on the solution level (Jean et al., 2018): https://doi.org/10.1007/s00190-018-1123-5). The resulting COST-G combined gravity fields are validated assessing their signal and noise content in the spectral and spatial domain (Meyer et al., 2019: https://doi.org/10.1007/s00190-019-01274-6) and by the COST-G Product Evaluation Group (PEG).