Submesoscale Eddies
Recent observations in the upper layer of the Canada Basin [26] show that there are
small eddies with the sizes of about 2–4 km and orbital velocities up to 20 cm/s so
that the Rossby number is Ro =
U
fL = Oð1Þ, where U, L are characteristic scales of
velocity and length. These numbers obviously differ from the ones in the case of
mesoscale eddies, in which the Rossby number is in the range 0.1–0.01. Such
eddies are classified as “submesoscale” ones; it was established that they are
responsible for the re-stratification of the upper layer during winter. An important
feature of these eddies is the relatively high vertical velocity W ∼ 10
−4
–10
−3
⋅ U ∼
1–10 meters per day, in contrast with the mesoscale eddies with the vertical
velocities about W ∼ 10
−4
–10
−3
⋅ U ∼ 1–10 meters per day.
It is interesting that the very existence of the ocean submesoscale eddies was
found mainly due to the numerical modeling and ocean biochemistry satellite
remote sensing development [12].
The features of the submesoscale eddies, their role in the large-scale temperature
and salinity structures and the possibility of using the existing parameterizations [3]
remain absolutely uninvestigated in the Arctic Ocean.
Fig. 1 The scales, typical for the ocean at mid-latitudes and in the Arctic Ocean. The resolutions
appropriate to describe submesoscale eddies are depicted by captures in ovals. Note the “gray
zone” between meso- and submesoscale eddy diameters in the Arctic Ocean, which roughly
coincides with the transition zone from the hydrostatic to non-hydrostatic regimes
Arctic Ocean Modeling: The Consistent Physics on the Path …
563
Recent observations in the upper layer of the Canada Basin [26] show that there are
small eddies with the sizes of about 2–4 km and orbital velocities up to 20 cm/s so
that the Rossby number is Ro =
U
fL = Oð1Þ, where U, L are characteristic scales of
velocity and length. These numbers obviously differ from the ones in the case of
mesoscale eddies, in which the Rossby number is in the range 0.1–0.01. Such
eddies are classified as “submesoscale” ones; it was established that they are
responsible for the re-stratification of the upper layer during winter. An important
feature of these eddies is the relatively high vertical velocity W ∼ 10
−4
–10
−3
⋅ U ∼
1–10 meters per day, in contrast with the mesoscale eddies with the vertical
velocities about W ∼ 10
−4
–10
−3
⋅ U ∼ 1–10 meters per day.
It is interesting that the very existence of the ocean submesoscale eddies was
found mainly due to the numerical modeling and ocean biochemistry satellite
remote sensing development [12].
The features of the submesoscale eddies, their role in the large-scale temperature
and salinity structures and the possibility of using the existing parameterizations [3]
remain absolutely uninvestigated in the Arctic Ocean.
Fig. 1 The scales, typical for the ocean at mid-latitudes and in the Arctic Ocean. The resolutions
appropriate to describe submesoscale eddies are depicted by captures in ovals. Note the “gray
zone” between meso- and submesoscale eddy diameters in the Arctic Ocean, which roughly
coincides with the transition zone from the hydrostatic to non-hydrostatic regimes
Arctic Ocean Modeling: The Consistent Physics on the Path …
563