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 time-series in the time period 2004-2010, and extrapolated to earlier or later epochs to avoid poor quality solutions in the early or late phase of the GRACE mission to impact the signal model (each month is weighted equally).

For each spherical harmonic coefficient an individual model is fitted. For comparisons in the spherical harmonic domain no filter is applied. Low degree anomalies are dominated by residual signal content (non-seasonal hydrology), while the higher degree anomalies are dominated by noise.

The accuracy assessment (errors) of the combined solutions is derived empirically from the differences to the individual gontributions.

month
degree amplitudes of anomalies
including JPL
degree amplitudes of errors
04/2002
anomalies
anomalies
errors
05/2002
anomalies
anomalies
errors
08/2002
anomalies
anomalies
errors
09/2002
anomalies
anomalies
errors
10/2002
anomalies
anomalies
errors
11/2002
anomalies
anomalies
errors
12/2002
anomalies
anomalies
errors
01/2003
anomalies
anomalies
errors
02/2003
anomalies
anomalies
errors
03/2003
anomalies
anomalies
errors
04/2003
anomalies
anomalies
errors
05/2003
anomalies
anomalies
errors
07/2003
anomalies
anomalies
errors
08/2003
anomalies
anomalies
errors
09/2003
anomalies
anomalies
errors
10/2003
anomalies
anomalies
errors
11/2003
anomalies
anomalies
errors
12/2003
anomalies
anomalies
errors
01/2004
anomalies
anomalies
errors
02/2004
anomalies
anomalies
errors
03/2004
anomalies
anomalies
errors
04/2004
anomalies
anomalies
errors
05/2004
anomalies
anomalies
errors
06/2004
anomalies
anomalies
errors
07/2004
anomalies
anomalies
errors
08/2004
anomalies
anomalies
errors
09/2004
anomalies
anomalies
errors
10/2004
anomalies
anomalies
errors
11/2004
anomalies
anomalies
errors
12/2004
anomalies
anomalies
errors
01/2005
anomalies
anomalies
errors
02/2005
anomalies
anomalies
errors
03/2005
anomalies
anomalies
errors
04/2005
anomalies
anomalies
errors
05/2005
anomalies
anomalies
errors
06/2005
anomalies
anomalies
errors
07/2005
anomalies
anomalies
errors
08/2005
anomalies
anomalies
errors
09/2005
anomalies
anomalies
errors
10/2005
anomalies
anomalies
errors
11/2005
anomalies
anomalies
errors
12/2005
anomalies
anomalies
errors
01/2006
anomalies
anomalies
errors
02/2006
anomalies
anomalies
errors
03/2006
anomalies
anomalies
errors
04/2006
anomalies
anomalies
errors
05/2006
anomalies
anomalies
errors
06/2006
anomalies
anomalies
errors
07/2006
anomalies
anomalies
errors
08/2006
anomalies
anomalies
errors
09/2006
anomalies
anomalies
errors
10/2006
anomalies
anomalies
errors
11/2006
anomalies
anomalies
errors
12/2006
anomalies
anomalies
errors
01/2007
anomalies
anomalies
errors
02/2007
anomalies
anomalies
errors
03/2007
anomalies
anomalies
errors
04/2007
anomalies
anomalies
errors
05/2007
anomalies
anomalies
errors
06/2007
anomalies
anomalies
errors
07/2007
anomalies
anomalies
errors
08/2007
anomalies
anomalies
errors
09/2007
anomalies
anomalies
errors
10/2007
anomalies
anomalies
errors
11/2007
anomalies
anomalies
errors
12/2007
anomalies
anomalies
errors
01/2008
anomalies
anomalies
errors
02/2008
anomalies
anomalies
errors
03/2008
anomalies
anomalies
errors
04/2008
anomalies
anomalies
errors
05/2008
anomalies
anomalies
errors
06/2008
anomalies
anomalies
errors
07/2008
anomalies
anomalies
errors
08/2008
anomalies
anomalies
errors
09/2008
anomalies
anomalies
errors
10/2008
anomalies
anomalies
errors
11/2008
anomalies
anomalies
errors
12/2008
anomalies
anomalies
errors
01/2009
anomalies
anomalies
errors
02/2009
anomalies
anomalies
errors
03/2009
anomalies
anomalies
errors
04/2009
anomalies
anomalies
errors
05/2009
anomalies
anomalies
errors
06/2009
anomalies
anomalies
errors
07/2009
anomalies
anomalies
errors
08/2009
anomalies
anomalies
errors
09/2009
anomalies
anomalies
errors
10/2009
anomalies
anomalies
errors
11/2009
anomalies
anomalies
errors
12/2009
anomalies
anomalies
errors
01/2010
anomalies
anomalies
errors
02/2010
anomalies
anomalies
errors
03/2010
anomalies
anomalies
errors
04/2010
anomalies
anomalies
errors
05/2010
anomalies
anomalies
errors
06/2010
anomalies
anomalies
errors
07/2010
anomalies
anomalies
errors
08/2010
anomalies
anomalies
errors
09/2010
anomalies
anomalies
errors
10/2010
anomalies
anomalies
errors
11/2010
anomalies
anomalies
errors
12/2010
anomalies
anomalies
errors
02/2011
anomalies
anomalies
errors
03/2011
anomalies
anomalies
errors
04/2011
anomalies
anomalies
errors
05/2011
anomalies
anomalies
errors
07/2011
anomalies
anomalies
errors
08/2011
anomalies
anomalies
errors
09/2011
anomalies
anomalies
errors
10/2011
anomalies
anomalies
errors
11/2011
anomalies
anomalies
errors
12/2011
anomalies
anomalies
errors
01/2012
anomalies
anomalies
errors
02/2012
anomalies
anomalies
errors
03/2012
anomalies
anomalies
errors
04/2012
anomalies
anomalies
errors
06/2012
anomalies
anomalies
errors
07/2012
anomalies
anomalies
errors
08/2012
anomalies
anomalies
errors
09/2012
anomalies
anomalies
errors
11/2012
anomalies
anomalies
errors
12/2012
anomalies
anomalies
errors
01/2013
anomalies
anomalies
errors
02/2013
anomalies
anomalies
errors
04/2013
anomalies
anomalies
errors
05/2013
anomalies
anomalies
errors
06/2013
anomalies
anomalies
errors
07/2013
anomalies
anomalies
errors
10/2013
anomalies
anomalies
errors
11/2013
anomalies
anomalies
errors
12/2013
anomalies
anomalies
errors
01/2014
anomalies
anomalies
errors
03/2014
anomalies
anomalies
errors
04/2014
anomalies
anomalies
errors
05/2014
anomalies
anomalies
errors
06/2014
anomalies
anomalies
errors
08/2014
anomalies
anomalies
errors
09/2014
anomalies
anomalies
errors
10/2014
anomalies
anomalies
errors
11/2014
anomalies
anomalies
errors
01/2015
anomalies
anomalies
errors
02/2015
anomalies
anomalies
errors
03/2015
anomalies
anomalies
errors
04/2015
anomalies
anomalies
errors
05/2015
anomalies
anomalies
errors
07/2015
anomalies
anomalies
errors
08/2015
anomalies
anomalies
errors
09/2015
anomalies
anomalies
errors
12/2015
anomalies
anomalies
errors
01/2016
anomalies
anomalies
errors
02/2016
anomalies
anomalies
errors
03/2016
anomalies
anomalies
errors
05/2016
anomalies
anomalies
errors
06/2016
anomalies
anomalies
errors
07/2016
anomalies
anomalies
errors
08/2016
anomalies
anomalies
errors
11/2016
anomalies
anomalies
errors
12/2016
anomalies
anomalies
errors
01/2017
anomalies
anomalies
errors
03/2017
anomalies
anomalies
errors
04/2017
anomalies
anomalies
errors
05/2017
anomalies
anomalies
errors
06/2017
anomalies
anomalies
errors