Time-variable gravity field models on monthly and weekly basis

GFZ’s monthly and weekly time-variable GRACE gravity field models are freely distributed in the form of GRACE Level-2 products, i.e. as sets of spherical harmonic coefficients representing the Earth’s potential field for a dedicated time-period. Different time-series for different releases (along with helpful documentation) are available at the two GRACE archives ISDC and PODAAC. Here you can also find the monthly GRACE SDS newsletter which provides an up to date status of available Level-1 and Level-2 products of the GRACE Science Data System.

Monthly time-series of gravity field models are available for releases 01 till 05. Detailed information about the current release (GFZ RL05) can be found here.

Weekly time-series of gravity field models are derived by solving subsets (aligned to GPS weeks) of the monthly normal equation systems. They offer an increased resolution in time at the expense of decreased resolution in space. Weekly models are only available for releases 04 and 05 and can be downloaded from the ISDC archive.

Static gravity field models

Additionally, GFZ – in cooperation with GRGS – derives static, i.e. long-term mean, satellite-only (from combination of GOCE, GRACE, CHAMP and/or LAGEOS tracking data) as well as combined (with terrestrial gravity data) so-called EIGEN (European Improved Gravity model of the Earth by New techniques) gravity field models. A list of available EIGEN models is given below. All of these models can be downloaded from the ICGEM data base at GFZ.

• Combined gravity field model EIGEN-6C2 complete to degree and order 1949 from GOCE, GRACE, LAGEOS and surface gravity data, released on December 10, 2012.
• Satellite-only gravity field model GO_CONS_GCF_2_DIR_R3 complete to degree and order 240 from GOCE, GRACE and LAGEOS data. This model is release 3 of the official ESA GOCE model by means of the Direct Approach and was computed by GFZ and GRGS behalf of ESA within the framework of the GOCE High Level Processing Facility (GOCE-HPF).
• Combined gravity field model EIGEN-6C complete to degree and order 1420 from GOCE, GRACE, LAGEOS and surface gravity data, released on June 27, 2011.
• Satellite-only gravity field model EIGEN-6S complete to degree and order 240 from GOCE, GRACE and LAGEOS data, released on June 27, 2011.
• Combined gravity field model EIGEN-51C complete to degree and order 359 from GRACE, CHAMP and surface gravity data, released on June 22, 2010.
• Combined gravity field model EIGEN-5C complete to degree and order 360 from GRACE, LAGEOS and surface gravity data, released on September 29, 2008.
• Satellite-only gravity field model EIGEN-5S complete to degree and order 150 from GRACE and LAGEOS data, released on September 29, 2008.
• Satellite-only gravity field model EIGEN-GL04S1 complete to degree and order 150 from GRACE and LAGEOS data, released May 24, 2006.
• Combined gravity field model EIGEN-GL04C complete to degree and order 360 from GRACE, LAGEOS and surface gravity data, released on March 31, 2006.
• Combined gravity field model EIGEN-CG03C complete to degree and order 360 from CHAMP, GRACE and surface gravity data, released on May 12, 2005.
• Combined gravity field model EIGEN-CG01C complete to degree and order 360 from CHAMP, GRACE and surface gravity data, released on October 29, 2004.
• GRACE gravity field model EIGEN-GRACE02S complete to degree and order 150 released on February 13, 2004 to the GRACE Science Team and August 9, 2004 to the public.
• First GFZ GRACE gravity field model EIGEN-GRACE01S complete to degree and order 140 released on July 25, 2003.

Links to gravity field results of other processing centers or additional help for visualization procedures or software tools for gravity field coefficients manipulation and transformation can be found here.