English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Report

Geostrophic Ocean Surface Velocities from TOPEX Altimetry, and CHAMP and GRACE Satellite Gravity Models

Authors
/persons/resource/dobslaw

Dobslaw,  Henryk
1.3 Earth System Modelling , 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

Schwintzer,  Peter
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
1.2 Global Geomonitoring and Gravity Field , 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Gravity Field and Gravimetry -2009, Geoengineering Centres, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

/persons/resource/bar

Barthelmes,  Franz
1.2 Global Geomonitoring and Gravity Field , 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

/persons/resource/flechtne

Flechtner,  Frank
1.2 Global Geomonitoring and Gravity Field , 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

Reigber,  Christoph
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
1.1 GPS/GALILEO Earth Observation, 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

Schmidt,  Roland
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
1.2 Global Geomonitoring and Gravity Field , 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

Schöne,  Tilo
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
1.2 Global Geomonitoring and Gravity Field , 1.0 Geodesy and Remote Sensing, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

Wiehl,  Martin
Scientific Technical Report STR, Deutsches GeoForschungsZentrum;
Publikationen aller GRACE-unterstützten Projekte, Deutsches GeoForschungsZentrum;

External Ressource
No external resources are shared
Fulltext (public)

0407.pdf
(Publisher version), 2MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Dobslaw, H., Schwintzer, P., Barthelmes, F., Flechtner, F., Reigber, C., Schmidt, R., Schöne, T., Wiehl, M. (2004): Geostrophic Ocean Surface Velocities from TOPEX Altimetry, and CHAMP and GRACE Satellite Gravity Models, (Scientific Technical Report STR ; 04/07), Potsdam : Deutsches GeoForschungsZentrum GFZ, 22 p.
https://doi.org/10.48440/gfz.b103-04074


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_8633
Abstract
Recently released global gravity field models generated solely from CHAMP and GRACE satellite observations allow with an unprecedented accuracy and resolution the recovery of the mean sea surface topography from the difference between an altimetry-based mean sea surface height model and the gravity model's derived geoid. Here the CHAMP EIGEN-2 gravity field model, and the first GFZ GRACE gravity model, EIGEN-GRACE01S, are used. The mean sea surface height model has been compiled from four years'; worth of TOPEX altimeter data. To evaluate the accuracy and resolution limits of the CHAMP and GRACE geoids for the envisaged application, a low pass filter in the spatial domain with different cut-off wavelengths has been applied to the geoid and sea surface data before subtraction. The minimum wavelength, where noisy and erroneous features in the recovered sea surface topography are minimised, can be interpreted as an indicator for the best suited common spatial resolution. The EIGEN-2 model's geoid has been tested to have a resolution of 1800 km, which corresponds to a truncation degree of l = 22 in terms of spherical harmonics. Using the EIGEN-GRACE01S model, the resolution could be extended to 1000 km (l = 40). These boundaries can be attributed to the geoid's error, exceeding 2 cm in case of the CHAMP model, and in case of the GRACE model to spurious systematic signals increasing with increasing spherical harmonic degree. The calculated sea surface topography models have been used to derive absolute geostrophic sea surface velocities. An error propagation shows that the requirement of 1 cm/s for geoid induced velocity errors is fulfilled at the given resolutions for all latitudes excluding a narrow equatorial band. Maximum geostrophic velocities are derived in the 1000 km-resolution model for the Kuroshio region with 40 cm/s, and for the Gulf Stream east off Cape Hatteras with 25 cm/s.