Rock-Water-Ice topographic-isostatic gravity field model 2012 (RWI 2012 model)
Cite as:
Grombein, Thomas; Seitz, Kurt; Heck, Bernhard (2014): Rock-Water-Ice topographic-isostatic gravity field model 2012 (RWI 2012 model). GFZ Data Services. https://doi.org/10.5880/ICGEM.2014.001
Status
I N R E V I E W : Grombein, Thomas; Seitz, Kurt; Heck, Bernhard (2014): Rock-Water-Ice topographic-isostatic gravity field model 2012 (RWI 2012 model). GFZ Data Services. https://doi.org/10.5880/ICGEM.2014.001
Abstract
High-resolution spherical harmonic representation of the Earth's topographic, isostatic, and topographic-isostatic gravitational potential based on a three-layer decomposition of the topography with variable density values and a modified Airy-Heiskanen concept incorporating seismic Moho depths.
Main features:
- Three-layer decomposition of the topography using information of the 5'x5'global topographic database DTM2006.0
- Rigorous separate modeling of rock, water, and ice masses with layer-specific density values (2670, 1000, 920 kg m-3)
- Avoidance of geometry changes compared to classical condensation methods (e.g. rock-equivalent heights)
- Ellipsoidal arrangement of the topography using the GRS80 ellipsoid as reference surface
- Adapted and modified Airy-Heiskanen isostatic concept - Incorporation of seismic Moho depths derived from CRUST2.0
- Location-dependent estimation of the crust-mantle density contrast
Processing:
- Forward modelling in the space domain using tesseroid mass bodies
- Transformation of global gridded values to the frequency domain by applying harmonic analysis up to degree and order 1800
Model versions:
- Spherical harmonic coefficients of the RWI model are provided by three versions
(GM = 3.986004415e+14 m3 s-2, a = 6378136.3 m):
RWI_TOPO_2012 (topographic potential)
RWI_ISOS_2012 (isosatic potential)
RWI_TOIS_2012 (topographic-isostatic potential)
- To allow the evaluation of the RWI model by synthesis software that by default subtracts the coefficients of a normal gravity field, three additional versions are available:
RWI_TOPO_2012_plusGRS80 (topographic potential + GRS80)
RWI_ISOS_2012_plusGRS80 (isosatic potential + GRS80)
RWI_TOIS_2012_plusGRS80 (topogr.-isostatic potential + GRS80)
where the following zonal harmonic coefficients of the GRS80 normal gravity field are added to the coefficients of the RWI model:
Note that these coefficients are already rescaled to the above specified parameters GM and a of the RWI model.
Details about the used DTM2006.0 topography model can be found in Pavlis et al. (2012, https://doi.org/10.1029/2011JB008916). Details about the used CRUST2.0 model is available from Laske et al. (2000, https://igppweb.ucsd.edu/~gabi/crust2.html).
Authors
Grombein, Thomas;Geodetic Institute, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany;Astronomical Institute, University of Bern (AIUB), Bern, Switzerland
Seitz, Kurt;Geodetic Institute, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Heck, Bernhard;Geodetic Institute, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Contact
Grombein, Thomas; Astronomical Institute, University of Bern (AIUB), Bern, Switzerland;
CharacterString: High-resolution spherical harmonic representation of the Earth's topographic, isostatic, and topographic-isostatic gravitational potential based on a three-layer decomposition of the topography with variable density values and a modified Airy-Heiskanen concept incorporating seismic Moho depths.
Main features:
- Three-layer decomposition of the topography using information of the 5'x5'global topographic database DTM2006.0
- Rigorous separate modeling of rock, water, and ice masses with layer-specific density values (2670, 1000, 920 kg m-3)
- Avoidance of geometry changes compared to classical condensation methods (e.g. rock-equivalent heights)
- Ellipsoidal arrangement of the topography using the GRS80 ellipsoid as reference surface
- Adapted and modified Airy-Heiskanen isostatic concept - Incorporation of seismic Moho depths derived from CRUST2.0
- Location-dependent estimation of the crust-mantle density contrast
Processing:
- Forward modelling in the space domain using tesseroid mass bodies
- Transformation of global gridded values to the frequency domain by applying harmonic analysis up to degree and order 1800
Model versions:
- Spherical harmonic coefficients of the RWI model are provided by three versions
(GM = 3.986004415e+14 m3 s-2, a = 6378136.3 m):
RWI_TOPO_2012 (topographic potential)
RWI_ISOS_2012 (isosatic potential)
RWI_TOIS_2012 (topographic-isostatic potential)
- To allow the evaluation of the RWI model by synthesis software that by default subtracts the coefficients of a normal gravity field, three additional versions are available:
RWI_TOPO_2012_plusGRS80 (topographic potential + GRS80)
RWI_ISOS_2012_plusGRS80 (isosatic potential + GRS80)
RWI_TOIS_2012_plusGRS80 (topogr.-isostatic potential + GRS80)
where the following zonal harmonic coefficients of the GRS80 normal gravity field are added to the coefficients of the RWI model:
C( 0,0) = 0.100000014676351e+01
C( 2,0) = -0.484167032228604e-03
C( 4,0) = 0.790304535833168e-06
C( 6,0) = -0.168725253450154e-08
C( 8,0) = 0.346053594536695e-11
C(10,0) = -0.265006548323563e-14
C(12,0) = -0.410788602320538e-16
C(14,0) = 0.447176931400485e-18
C(16,0) = -0.346362561442980e-20
Note that these coefficients are already rescaled to the above specified parameters GM and a of the RWI model.
Details about the used DTM2006.0 topography model can be found in Pavlis et al. (2012, https://doi.org/10.1029/2011JB008916). Details about the used CRUST2.0 model is available from Laske et al. (2000, https://igppweb.ucsd.edu/~gabi/crust2.html).
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CharacterString: Grombein, Thomas
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CharacterString: Astronomical Institute, University of Bern (AIUB), Bern, Switzerland
CI_OnLineFunctionCode (codeList=http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode codeListValue=http://www.isotc211.org/2005/resources/Codelist/gmxCodelists.xml#CI_OnLineFunctionCode_information): information
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Abstract
;Geodetic Institute, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany;Astronomical Institute, University of Bern (AIUB), Bern, Switzerland
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