7 Interpretation of SAR Signatures of the Sea Surface
123
Fig. 7.8 ERS-2 SAR image
(∼ 100 km × 100 km) taken
on 4 October 2003 at 12:40
UTC. The arrows show
movement direction of the
radar signatures and the
numbers denote their speed in
m/s estimated with the use of
the co-located Envisat ASAR
and ERS-2 SAR images
The highest V values (5–6 m/s) were derived for the atmospheric features (not
shown). The velocities of the oceanic signatures (the Soya Warm Current front,
packets of IWs, etc.) are significantly less and lie between 0 and 0.9 m/s (see
Fig. 7.8). The arrows in Fig. 7.8 indicate direction of movement, while the numbers near the arrows are the respective velocities in m/s. The southward West
Sakhalin Current is observed to the south of Cape Kuznetsov. The speed of this
current changes rapidly, as the distance D from the coast increases: at D = 3 km
V = 0.4 m/s and at D = 5 km V = 0.8 m/s. The small-sized radar signatures,
aligned from Cape Krilion and Rock of Danger to the west, indicate the presence of
strong tidal outflow from the Okhotsk Sea. The signatures near Cape Krilion have
an arched shape. The tidal outflow moves the radar signature C toward the Hokkaido
coast at the speed of 0.4 m/s.
At the same time, the radar signature T moves westward at the speed of 0.7–0.9
m/s (Fig. 7.8). Close inspection of the derived movement shows that the bright radar
signature W, corresponding to the convergence zone between the Tsushima Current
and the West Sakhalin Current, undergoes cyclonic displacement. Its southern part
moves to the northwest at the speed of 0.5 m/s and northern one moves toward the
coast at the speed of 0.3 m/s. A narrow light-dark band in the lower right hand
section of Fig. 7.8 is very likely an IW soliton. Its northern side moves westward
at a rate of 0.8 m/s, while the southern one displaces slower (0.3 m/s), due to the
Soya Warm Current influence. Several packets of IWs are visible to the east of the
123
Fig. 7.8 ERS-2 SAR image
(∼ 100 km × 100 km) taken
on 4 October 2003 at 12:40
UTC. The arrows show
movement direction of the
radar signatures and the
numbers denote their speed in
m/s estimated with the use of
the co-located Envisat ASAR
and ERS-2 SAR images
The highest V values (5–6 m/s) were derived for the atmospheric features (not
shown). The velocities of the oceanic signatures (the Soya Warm Current front,
packets of IWs, etc.) are significantly less and lie between 0 and 0.9 m/s (see
Fig. 7.8). The arrows in Fig. 7.8 indicate direction of movement, while the numbers near the arrows are the respective velocities in m/s. The southward West
Sakhalin Current is observed to the south of Cape Kuznetsov. The speed of this
current changes rapidly, as the distance D from the coast increases: at D = 3 km
V = 0.4 m/s and at D = 5 km V = 0.8 m/s. The small-sized radar signatures,
aligned from Cape Krilion and Rock of Danger to the west, indicate the presence of
strong tidal outflow from the Okhotsk Sea. The signatures near Cape Krilion have
an arched shape. The tidal outflow moves the radar signature C toward the Hokkaido
coast at the speed of 0.4 m/s.
At the same time, the radar signature T moves westward at the speed of 0.7–0.9
m/s (Fig. 7.8). Close inspection of the derived movement shows that the bright radar
signature W, corresponding to the convergence zone between the Tsushima Current
and the West Sakhalin Current, undergoes cyclonic displacement. Its southern part
moves to the northwest at the speed of 0.5 m/s and northern one moves toward the
coast at the speed of 0.3 m/s. A narrow light-dark band in the lower right hand
section of Fig. 7.8 is very likely an IW soliton. Its northern side moves westward
at a rate of 0.8 m/s, while the southern one displaces slower (0.3 m/s), due to the
Soya Warm Current influence. Several packets of IWs are visible to the east of the