movement. At high wind speeds, only contours of the eddy or its center can be
drawn on RI due to shear-wave mechanism (the interaction of waves and currents);
in this case it is often not possible to determine eddy size and direction of rotation.
The manifestation of eddies in radar imagery can be also due to the young, not solid
ice.
For the purposes of illustration we shall use in this paper a few visible band
images (from the QuickBird and the Landsat-5 TM sensors) as well as satellite radar
images obtained from the ASAR Envisat, SAR ERS-2, and Sentinel-1.
Submesoscale Eddies in the Russian Seas
The Black Sea
The semi-enclosed Black Sea is characterized by intense mesoscale dynamics.
Typical elements of the circulation are mesoscale (∼20–100 km) eddies, vortex
dipoles, jets, the lifetime of which reaches several months (R d in the open Black Sea
is equal to 15–20 km, in the shelf zone near Gelendzhik it is 8 km [37]). The main
results of the study of mesoscale dynamics of the Black Sea and its connection with
the large-scale water circulation (the Rim Current propagating cyclonically),
dependence on the wind forcing and topography of the continental slope, horizontal
and vertical exchange in the active layer of the Black Sea are presented in numerous
works (e.g., [6, 7, 20, 24, 33, 36]).
Satellite high-resolution images reveal submesoscale eddies both in the coastal
zone and in the deep area of the Black Sea. A set of visible images of the QuickBird
satellite, which was exhibited in the programme “Google Earth” in 2009 [18],
demonstrate the variety of eddies with sizes of 1–10 km in the coastal zone, which
appear due to the presence of water with high content of suspended matter and
surfactants (see Figs. 1, 2, 3, 4, 5 and 6), the dates of these images were not
specified).
Anticyclonic eddy with a diameter of about 7 km is clearly manifested in the
region of the villages of Khosta and Kudepsta in Fig. 1. Source of suspended matter
is the outflow of the rivers Mzymta and Psou located to the southeast of this point.
The formation of this eddy may be caused by the instability of the coastal northwestward current associated with local features of the shoreline.
A cyclonic eddy with a diameter of 4 km is seen in Fig. 2, in the area of the
Bakalskaya Spit (north-western coast of Crimea). This eddy is manifested in the
field of suspended matter, the source of which may be only local resuspension of
waters near the sandy spit under the action of wind waves. It could be formed by
rounding the spit with a coastal current.
A cyclonic eddy with a diameter of 2 km is observed at a distance of 5 km from
the coast in the area of a northern suburb of Sochi (village of Mamay, Fig. 3). In
this case, a spiral vortex is manifested due to the presence on the sea surface of a
large amount of surfactant. This cyclone could be a result of short-term wind
Satellite Remote Sensing of Submesoscale Eddies …
399
drawn on RI due to shear-wave mechanism (the interaction of waves and currents);
in this case it is often not possible to determine eddy size and direction of rotation.
The manifestation of eddies in radar imagery can be also due to the young, not solid
ice.
For the purposes of illustration we shall use in this paper a few visible band
images (from the QuickBird and the Landsat-5 TM sensors) as well as satellite radar
images obtained from the ASAR Envisat, SAR ERS-2, and Sentinel-1.
Submesoscale Eddies in the Russian Seas
The Black Sea
The semi-enclosed Black Sea is characterized by intense mesoscale dynamics.
Typical elements of the circulation are mesoscale (∼20–100 km) eddies, vortex
dipoles, jets, the lifetime of which reaches several months (R d in the open Black Sea
is equal to 15–20 km, in the shelf zone near Gelendzhik it is 8 km [37]). The main
results of the study of mesoscale dynamics of the Black Sea and its connection with
the large-scale water circulation (the Rim Current propagating cyclonically),
dependence on the wind forcing and topography of the continental slope, horizontal
and vertical exchange in the active layer of the Black Sea are presented in numerous
works (e.g., [6, 7, 20, 24, 33, 36]).
Satellite high-resolution images reveal submesoscale eddies both in the coastal
zone and in the deep area of the Black Sea. A set of visible images of the QuickBird
satellite, which was exhibited in the programme “Google Earth” in 2009 [18],
demonstrate the variety of eddies with sizes of 1–10 km in the coastal zone, which
appear due to the presence of water with high content of suspended matter and
surfactants (see Figs. 1, 2, 3, 4, 5 and 6), the dates of these images were not
specified).
Anticyclonic eddy with a diameter of about 7 km is clearly manifested in the
region of the villages of Khosta and Kudepsta in Fig. 1. Source of suspended matter
is the outflow of the rivers Mzymta and Psou located to the southeast of this point.
The formation of this eddy may be caused by the instability of the coastal northwestward current associated with local features of the shoreline.
A cyclonic eddy with a diameter of 4 km is seen in Fig. 2, in the area of the
Bakalskaya Spit (north-western coast of Crimea). This eddy is manifested in the
field of suspended matter, the source of which may be only local resuspension of
waters near the sandy spit under the action of wind waves. It could be formed by
rounding the spit with a coastal current.
A cyclonic eddy with a diameter of 2 km is observed at a distance of 5 km from
the coast in the area of a northern suburb of Sochi (village of Mamay, Fig. 3). In
this case, a spiral vortex is manifested due to the presence on the sea surface of a
large amount of surfactant. This cyclone could be a result of short-term wind
Satellite Remote Sensing of Submesoscale Eddies …
399