Deep-water seamount wakes on SEASAT SAR image in the Gulf Stream region

A SEASAT synthetic aperture radar (SAR) image taken
over the Gulf Stream region shows streak-like patterns. The
physics of their generation and interaction with the Gulf
Stream are disputed. This study seeks a convincing interpretation
for the SAR imagery patterns. Bathymetric maps
show that the sea floor area beneath the streaks is the northeast
Hoyt Hills, where isolated seamounts with the heights of
20 to 140 m above the background sea floor are distributed.
All the SAR imagery streaks originate from these seamounts
and extend downstream. Thus the SAR imagery streaks are
interpreted as surface roughness imprints of the seamount
wakes. Hydrostatic flow dynamics of the generation of wakes
on the lee side of a solid obstacle is used to explain the
generation mechanism and internal structure of the seamount
wakes. The analysis indicates that boundary conditions and
hydrodynamic conditions are favorable for the generation
and vertical propagation of the seamount wakes to the upper
layer.

In summary, the above imagery features of the streaks
on the SEASAT SAR image indicate that they are imprints
of seamount wakes on the sea surface. The seamount wakes
are generated by the interaction between seamounts and the
Gulf Stream flow. In other words, seamounts serve as a disturbance
source, and the Gulf Stream provides a dynamical
source.