Dmitry Kaplunenko, POI, e-mail: dimkap@poi.dvo.ru
Alexander Ostrovskii, P.P. Shirshov Institute of Oceanology
Vyacheslav Lobanov, V.I.Il`ichev Pacific Oceanological Institute
Olga Trusenkova, V.I.Il`ichev Pacific Oceanological InstituteSvetlana Ladychenko, V.I.Il`ichev Pacific Oceanological Institute
Aleksander Lazaryuk, V.I.Il`ichev Pacific Oceanological InstituteDmitry Shvoev, P.P. Shirshov Institute of Oceanology

Study of abyssal circulation

JJ Park, 2009

Senjyu et al. (2005)

Study of abyssal circulation NorthWestern part ofJapan Sea

Profiler IO RAS «Aqualog»
30-40 mOcean Sensors• SBE 37SI CTProfiler• SBE41 CTD• SBE43f DO• Fluorometer• Aquadopp CM• Underwater winch

250 and 400 m

2 times a day

Aqualog mooring scheme onshore

Study of abyssal circulation NorthWestern part ofJapan Sea

Here we analyzed data on temperature,salinity
and oxygen, obtained during the period of its
work.

The Aqualog profiler had
been installed at the 440m depth over thecontinental slope off thePrimorye coast on April
18, 2015, and was
performing 4 profilings
per day up to the 60 m
depth until October 15,
2015 when it wasretrieved and data werecollected. The Aqualog
measurements included
pressure, temperature,salinity, current velocity
vectors, dissolved oxygen
concentration, acoustic
scattering strength,
turbidity, andfluorescence in the watercolumn between thesubsurface and near-Satellite data within area of Aqualog
installation

Sea surface temperature (SST) retrieved from NOAA satellite AVHRR imagery wasobtained from the Center for Regional Satellite Monitoring of Environment, FarEastern Branch of Russian Academy of Sciences, Vladivostok(http://satellite.dvo.ru/).

Ship borne data within area of Aqualog
installation

There is a considerable increase indissolved oxygen concentration around
42.5° N in the layer from the surface
down to 250 m, with the concentration
as high as 320 umol/kg even at the100 m depth. These features imply an
intrusion of colder, fresher, and oxygen
rich water in the 100-200 m layer.

In situ measurements during mesoscale
eddy passing area of Aqualog installation
Temperature, salinity and oxygen
concentration
at the 200 m depth increase by 1.51.8° C, 0.01-0.03 psu,
and 17 umol/kg, respectively, implying
an intrusion ofwarmer, saltier, and oxygen richer
water
It is also worth noting that there are nosuch extremes at the inshore ship
station at the distance of just few
kilometers
These features imply that intrusions ofdifferent water masses with sizes just few
kilometers occur in this area.

Conclusions
The Aqualog-profiler is efficient tool for study different scale processes
within shelf and shelf off area in the marginal seas like the Japan Sea
The obtained data from the Aqualog is well matched to the other kind ofdata available for study mesoscale activity within the areas of intensive
water exchange between shelf and open sea
The detected anticyclonic eddy moving southwestward with thePrimorye Current was detected from NOAA satellite AVHRR imagery
from May 30 through June 9 when the sky was free of clouds. The eddy
was moving southeastward with the Primorye Current, advecting cold

water from the current offshore at its eastern periphery and the warm
open sea water inshore at its western periphery.
Thus, this eddy represents an example of how large slope eddies
effectuate water exchange between shelf areas and deep sea Verticalstructure of this eddy can be determined from the Aqualog time series

GratitudesФото экспедиции

The authors wish to thank the captain and crew of R/V “Akademik M.A.
Lavrentiev” for their help during the cruise No. 69 and others

This study was supported by the grant No. 16-05-00899 from the Russian Fund of Fundamental
Research.