New ultrahigh‐resolution picture of Earth's gravity field

9 10 Abstract 11 We provide an unprecedented ultra-high resolution picture of Earth's gravity over all continents 12 and numerous islands within ± 60 degree latitude. This is achieved through augmentation of new 13 satellite and terrestrial gravity with topography data, and use of massive parallel computation 14 techniques, delivering local detail at ~200 m spatial resolution. As such, our work is the first-of- 15 its-kind to model gravity at unprecedented fine scales yet with near-global coverage. The new 16 picture of Earth's gravity encompasses a suite of gridded estimates of gravity accelerations, 17 radial and horizontal field components and quasigeoid heights at over 3 billion points covering 18 80% of Earth's land masses. We identify new candidate locations of extreme gravity signals, 19 suggesting that the CODATA standard for peak-to-peak variations in free-fall gravity is too low 20 by about 40%. The new models are beneficial for a wide range of scientific and engineering 21 applications and freely available to the public. 22 23 Keywords 24

[1]  W. Featherstone,et al.  Topographic/isostatic evaluation of newgeneration GOCE gravity field models , 2012 .

[2]  Christian Hirt,et al.  Prediction of vertical deflections from high-degree spherical harmonic synthesis and residual terrain model data , 2010 .

[3]  Future Satellite Gravimetry for Geodesy , 2004 .

[4]  Christian Hirt,et al.  Efficient and accurate high-degree spherical harmonic synthesis of gravity field functionals at the Earth’s surface using the gradient approach , 2012, Journal of Geodesy.

[5]  Sten Claessens.  Solutions to ellipsoidal boundary value problems for gravity field modelling , 2006 .

[6]  Reiner Rummel,et al.  Height unification using GOCE , 2012 .

[7]  M. Wieczorek,et al.  Gravity and Topography of the Terrestrial Planets , 2015 .

[8]  Dorota A. Grejner-Brzezinska,et al.  Gravity Modeling for High‐Accuracy GPS/INS Integration , 1998 .

[9]  黄晓燕,et al.  IgG , 2010, Definitions.

[10]  Georges Balmino,et al.  Spherical harmonic modelling to ultra-high degree of Bouguer and isostatic anomalies , 2012, Journal of Geodesy.

[11]  T. H. Meyer,et al.  What Does Height Really Mean ? Part IV : GPS Heighting , 2007 .

[12]  Will Featherstone,et al.  GNSS‐based heighting in Australia: Current, emerging and future issues , 2008 .

[13]  N. K. Pavlis,et al.  Terrain-Related Gravimetric Quantities Computed for the Next EGM , 2006 .

[14]  A. Eicker,et al.  ITG-Grace2010: the new GRACE gravity field release computed in Bonn , 2010 .

[15]  C. C. Tscherning,et al.  The use of height data in gravity field approximation by collocation , 1981 .

[16]  Michael G. Sideris,et al.  Topographic Reductions in Gravity and Geoid Modeling , 2013 .

[17]  Rene Forsberg,et al.  A Study of Terrain Reductions, Density Anomalies and Geophysical Inversion Methods in Gravity Field Modelling , 1984 .

[18]  T. H. Meyer,et al.  What Does Height Really Mean? Part IV: GPS Orthometric Heighting , 2006 .

[19]  T. Gruber,et al.  Impact of GOCE Level 1b data reprocessing on GOCE-only and combined gravity field models , 2013, Studia Geophysica et Geodaetica.

[20]  A. B. WATTS,et al.  Isostasy and Flexure of the Lithosphere , 2001 .

[21]  Nico Sneeuw,et al.  The polar gap , 1997 .

[22]  F. Sansò,et al.  First GOCE gravity field models derived by three different approaches , 2011 .

[23]  N. K. Pavlis,et al.  The development and evaluation of the Earth Gravitational Model 2008 ( EGM 2008 ) , 2012 .

[24]  Andrew Jarvis,et al.  Hole-filled SRTM for the globe Version 4 , 2008 .

[25]  R. Pail,et al.  Alternative method for angular rate determination within the GOCE gradiometer processing , 2011 .

[26]  Will Featherstone,et al.  Combining EGM2008 and SRTM/DTM2006.0 residual terrain model data to improve quasigeoid computations in mountainous areas devoid of gravity data , 2010 .

[27]  N. K. Pavlis,et al.  The development and evaluation of the Earth Gravitational Model 2008 (EGM2008) , 2012 .

[28]  A. Jäggi,et al.  Combined satellite gravity field model GOCO01S derived from GOCE and GRACE , 2010 .

[29]  B. Taylor,et al.  CODATA recommended values of the fundamental physical constants: 2006 | NIST , 2007, 0801.0028.

[30]  R. Rapp.  Use of potential coefficient models for geoid undulation determinations using a spherical harmonic representation of the height anomaly/geoid undulation difference , 1997 .

[31]  Helmut Moritz,et al.  Geodetic Reference System 1980 , 1980 .

[32]  Christian Hirt.  RTM Gravity Forward-Modeling Using Topography/Bathymetry Data to Improve High-Degree Global Geopotential Models in the Coastal Zone , 2013 .

[33]  N. K. Pavlis,et al.  Earth Gravitational Model 2008 , 2008 .

[34]  C. Gerlach,et al.  Validation of GOCE global gravity field models using terrestrial gravity data in Norway , 2012 .

[35]  Christopher Jekeli,et al.  An analysis of vertical deflections derived from high-degree spherical harmonic models , 1999 .

[36]  B. Taylor,et al.  CODATA Recommended Values of the Fundamental Physical Constants: 2010 | NIST , 2007, 0801.0028.

[37]  D. Fabre,et al.  Global Bathymetry and Elevation Data at 30 Arc Seconds Resolution: SRTM30_PLUS , 2009 .

[38]  W. Featherstone,et al.  Is Australian Data Really Validating EGM2008, or Is EGM2008 Just in/Validating Australian Data? , 2010 .

[39]  Will Featherstone,et al.  The importance of using deviations of the vertical for the reduction of survey data to a geocentric datum , 2000 .

[40]  M. Drinkwater,et al.  GOCE: ESA’s First Earth Explorer Core Mission , 2003 .

[41]  Gerhard Wübbena,et al.  Mutual validation of GNSS height measurements and high-precision geometric-astronomical leveling , 2011 .

[42]  W. Featherstone,et al.  Complete spherical Bouguer gravity anomalies over Australia , 2009 .