NEW GLOBAL MEAN DYNAMIC TOPOGRAPHY FROM A GOCE GEOID MODEL , ALTIMETER MEASUREMENTS AND OCEANOGRAPHIC IN-SITU DATA

The use of recent GOCE geoid models together with an altimeter Mean Sea Surface significantly improves the estimate of the ocean Mean Dynamic Topography at 100 km resolution compared to the use of previous GRACE geoid models. However, at scales shorter than 100km, the combined effect of geoid omission and commission errors prevents from directly using such models to estimate the ocean MDT and additional information is needed. In this study, the methodology used by [1] to estimate the CNES-CLS09 MDT is applied to include the shortest scales provided by in-situ measurements of current velocities and dynamic heights and compute a new, high resolution Mean Dynamic Topography for the global ocean. Improvements over the previous CNES-CLS09 MDT are quantified through comparison to independent insitu velocities.

[1]  F. Hernandez,et al.  High‐frequency response of wind‐driven currents measured by drifting buoys and altimetry over the world ocean , 2003 .

[2]  S. Bruinsma,et al.  Accuracy of the Preliminary GOCE Geoid Models from an Oceanographic Perspective , 2012 .

[3]  N. Picot,et al.  The CNES_CLS11 Global Mean Sea Surface Computed from 16 Years of Satellite Altimeter Data , 2012 .

[4]  M. Rio.  Use of Altimeter and Wind Data to Detect the Anomalous Loss of SVP-Type Drifter’s Drogue , 2012 .

[5]  Russ E. Davis,et al.  Water-following characteristics of a mixed layer drifter , 1987 .

[6]  Semyon A. Grodsky,et al.  Spurious trends in global surface drifter currents , 2011 .

[7]  G. Dibarboure,et al.  Velocity Mapping Capabilities of Present and Future Altimeter Missions: The Role of High-Frequency Signals , 2002 .

[8]  Ole Baltazar Andersen,et al.  DNSC08 mean sea surface and mean dynamic topography models , 2009 .

[9]  L. Centurioni,et al.  Removing Spurious Low-Frequency Variability in Drifter Velocities , 2013 .

[10]  Gilles Larnicol,et al.  New CNES‐CLS09 global mean dynamic topography computed from the combination of GRACE data, altimetry, and in situ measurements , 2011 .

[11]  D. Chambers,et al.  Mean Dynamic Topography of the Ocean Derived from Satellite and Drifting Buoy Data Using Three Different Techniques , 2009 .

[12]  Gilles Larnicol,et al.  What can we learn from Global Altimetry/Hydrography comparisons? , 2006 .

[13]  C. Förste,et al.  The new ESA satellite‐only gravity field model via the direct approach , 2013 .