Monthly anomalies are derived by subtraction of a deterministic signal model (bias, trend, annual and semi-annual variations) from the monthly solutions. The signal model is fitted to the monthly means of all GRACE-FO time-series contributing to the operational combination.

For each spherical harmonic coefficient an individual model is fitted, the signal model is evaluated at the middle epochs of the monthly solutions and then the spherical harmonic coefficients are expanded into global grids, applying a 400 km Gauss filter.

Anomalies over continents are mainly due to non-periodic hydrological signals or non-linear ice melt in polar regions. These should be consistent in all time-series. Anomalies over the oceans are dominated by noise and allow for a rough noise assessment of the different time-series.

month	AIUB	CSR	GFZ	GRGS	ITSG	JPL	LUH	COMB
06/2018
07/2018
10/2018
11/2018
12/2018
01/2019
02/2019
03/2019
04/2019
05/2019
06/2019
07/2019
08/2019
09/2019
10/2019
11/2019
12/2019
01/2020
02/2020
03/2020
04/2020
05/2020
06/2020
07/2020
08/2020
09/2020
10/2020
11/2020
12/2020
01/2021
02/2021
03/2021
04/2021
05/2021
06/2021
07/2021
08/2021
09/2021
10/2021
11/2021
12/2021
01/2022