Gulf Stream Surface Transport and Statistics at 69W from the Geosat Altimeter.

摘要

Geosat altimeter height measurements for the Gulf Stream for three subtracks from the Exact Repeat Mission were processed to remove the geoid and mean Gulf Stream height. A Gaussian model for the Gulf Stream velocity profile was used to predict the form of the residual height profiles seen by Geosat and the mean height profile, using estimates of the width and position derived from the height residuals. Estimates of the maximum surface velocity and the surface transport were obtained by a least squares fit of the synthetic height profiles to the data. Location statistics from the Geosat data were in good agreement with values obtained from infrared images of the Gulf Stream. Maximum surface velocities were typically between 1.2 and 2.0 mls. The time series showed that surface transport is correlated primarily with the magnitude of the surface velocities, although an anomalously large increase in surface transport in the winter of 1987-1988 was caused by an increase in the width of the Gulf Stream. Analysis of the average annual signal in transport showed maximum values in the late fall and minimum transport in the late spring. Maximum (minimum) surface transport generally occurred when the Gulf Stream was north (south) of its mean position. Reprints. (EDC)