Affordable Access

Estimating mean dynamic topography in the tropical Pacific Ocean from gravity and altimetry satellites

Authors
Publication Date
Keywords
  • Circulation Oceanique
  • Courant Geostrophique
  • Topographie
  • Niveau Marin
  • Altimetrie
  • Donnees Satellite
Disciplines
  • Biology
  • Earth Science
  • Geography

Abstract

Estimating mean dynamic topography in the tropical Pacific Ocean from gravity and altimetry satellites Estimating mean dynamic topography in the tropical Pacific Ocean from gravity and altimetry satellites Lionel Gourdeau LEGOS, Toulouse, France Jean Michel Lemoine GRGS, Toulouse, France Marie He´le`ne Rio ISAC, Rome, Italy Fabrice Hernandez CLS, Ramonville, France Received 18 July 2003; accepted 1 October 2003; published 28 October 2003. [1] A new geoid model, combining the CHAMP satellite gravity data and an accurate altimetric mean sea surface, was used to investigate the 1993–1999 mean dynamic topography in the tropical Pacific Ocean. The mean dynamic topography, represented by a spherical harmonic expansion to degree 60 appear to be consistent with our knowledge of the tropical circulation, notably the South Equatorial Counter Current which is clearly visible in the western Pacific. This satellite solution, validated with in-situ data, is independent from any climatology and has a resolution similar to other classical mean dynamic topographies. Altimetry combined with geodesy can thus provide an absolute sea level which will be useful for data assimilation and tropical oceanography. INDEX TERMS: 4231 Oceanography: General: Equatorial oceanography; 0920 Exploration Geophysics: Gravity methods; 1243 Geodesy and Gravity: Space geodetic surveys; 4223 Oceanography: General: Descriptive and regional oceanography; 4512 Oceanography: Physical: Currents. Citation: Gourdeau, L., J. M. Lemoine, M. H. Rio, and F. Hernandez, Estimating mean dynamic topography in the tropical Pacific Ocean from gravity and altimetry satellites, Geophys. Res. Lett., 30(20), 2062, doi:10.1029/2003GL018200, 2003. 1. Introduction [2] Because of geoid uncertainties, altimetric applications have concentrated on ocean variability, using sea level anomalies. Several satellite gravity missions such as CHAMP, GRACE and GOCE have been devised to provide high resolution, highly accurate ge

There are no comments yet on this publication. Be the first to share your thoughts.