This study presents a basic analysis of ERS-1 altimeter data, from its 3-da
y repeat track periods taken over a section of the Gulf Stream. Along track
variations of radar backscatter (sigma (o)) have been compared with positi
ons of the Gulf Stream derived from the composite maps of sea surface tempe
rature from ship and satellite-sensor observations, produced by NOAA. Varia
tions in sigma (o), indicating potential interaction with the Gulf Stream,
are found at both high and low wind speed conditions. At high wind speeds,
comparison with model wind data indicates that peaks in altimeter-derived w
ind speeds along the path of the North Wall of the Gulf Stream may be relat
ed to real increases in wind speed. A possible reason may be a tendency for
winter storm tracks to follow the same path as sections of the Gulf Stream
. At low wind speeds, minima in altimeter-derived winds are associated with
sections of the path of the Gulf Stream but there were no comparable occur
rences of low wind speeds in model wind fields, with implied consequences f
or winds derived from satellite sensor data. Although, for low wind speeds,
the cause of these 'anomalously high' backscatter regions is unknown, such
associated relatively 'calmer' waters have been previously noted as the re
sult either of a tendency for surface slicks to be confined to the shears a
ssociated with local current systems or by wave-current interaction mechani
sms causing a local reduction in the sea surface roughness.