ROLE OF OCEAN VARIABILITY AND DYNAMIC OCEAN TOPOGRAPHY IN THE RECOVERY OF THE MEAN SEA-SURFACE AND GRAVITY-ANOMALIES FROM SATELLITE ALTIMETER DATA

Procedures to calculate mean sea surface heights and gravity anomalies from altimeter-derived sea surface heights and along-track sea surfac e slopes using the least-squares collocation procedure are derived. Th e slope data is used when repeat track averaging is not possible to re duce ocean variability effects. Tests were carried out using Topex, Ge osat, ERS-1 [35-day and 168-day (2 cycle)] data. Calculations of gravi ty anomalies in the Gulf Stream region were made using the sea surface height and slope data. Tests were also made correcting the sea surfac e heights for dynamic ocean topography calculated from a degree 360 ex pansion of data from the POCM-4B global ocean circulation model. Compa risons of the anomaly predictions were carried out with ship data usin g anomalies calculated for this paper as well as others.