The role of an intense jet in the Tsugaru Strait in the formation of the
outflow gyre revealed using high-frequency radar data
The seasonal pattern of the eastward jet through the Tsugaru Strait
between 2014 and 2019 was investigated using surface velocity data
obtained from high-frequency radar located in the eastern part of the
strait. The vorticity-front-model was used to estimate the volume
transport of low-vorticity water and the intensity of the vorticity gap
at the front using the climatological mean zonal velocity distribution.
The flow mode at the outlet was then defined as either the summer/autumn
“gyre mode” or winter/spring “coastal mode”. The distribution of the
parameters was consistent with the theoretical understanding, showing
that in addition to the volume transport, an increase in the vorticity
gap can also contribute to the development of the gyre. The results also
suggest an impact from the jet in the strait on the coastal flow along
the coast of Japan.