REMOTELY-SENSED SEA-SURFACE THERMAL PATTERNS IN THE GULF OF CADIZ ANDTHE STRAIT OF GIBRALTAR - VARIABILITY, CORRELATIONS, AND RELATIONSHIPS WITH THE SURFACE WIND-FIELD
Am. Folkard et al., REMOTELY-SENSED SEA-SURFACE THERMAL PATTERNS IN THE GULF OF CADIZ ANDTHE STRAIT OF GIBRALTAR - VARIABILITY, CORRELATIONS, AND RELATIONSHIPS WITH THE SURFACE WIND-FIELD, J GEO RES-O, 102(C3), 1997, pp. 5669-5683
Satellite image sequences (covering periods of a few days throughout t
he annual cycle) of the waters off southern Iberia have been analyzed
in conjunction with concurrent surface wind speed data from coastal st
ations. Qualitative analysis reveals a large degree of temporal and sp
atial variability in the thermal signature of the sea surface over per
iods of both a few days and several months. During the summer, a cool
seasurface temperature signature extends from the western Iberian coas
t around Cape St. Vincent and eastward as far as Fare. At the same tim
e, a warm signature originating on the Iberian coast between Faro and
Cadiz extends into the Strait of Gibraltar. These two features are sho
wn to sometimes adopt more westerly positions, and the strait experien
ces regions of cool thermal signature originating at its southern side
. During winter, the surface flow into the Mediterranean through the S
trait of Gibraltar is anomalously warm and appears to come from the in
terior of the Gulf of Cadiz. Quantitative measurements show that tempo
ral variability over timescales of a few days at individual sites is m
aximum in midsummer. Spatial thermal variability over the whole region
is found to peak toward the end of the summer. Statistical analyses o
f the data reveal the coupling between the surface wind field in the G
ulf of Cadiz and the surface thermal pattern (especially during the su
mmer). Wind-induced, across-stream upwelling in the Strait of Gibralta
r, although dynamically subordinate to tidal and density-driven proces
ses, is shown to occasionally dominate the surface thermal signature.