Russian Academy of Sciences
Talk presented at SAMOC-3 Meeting, Rio de Janeiro, Brazil, May 11, 2010
Physical Oceanography at SIO RAS,
and Selected Results on the South Atlantic
Peter O. Zavialov Deputy Director, Shirshov Institute of Oceanology Head, Physical Oceanography Division
Founded: 1946Employees: ~1200Scientists: ~600PhD’s: ~160 DSc’s: ~90Graduate students: ~60Fleet: 6
Biological OceanographyDivision
GeologicalOceanographyDivision
PhysicalOceanographyDivision
OceanEngineeringDivision
6 Labs 13 Labs 13 Labs 7 Labs
P.P.SHIRSHOV INSTITUTE OF OCEANOLOGY (SIO RAS)
+ 5 regional filial branches
Faculty and staff : 108 scientists, 53 engineers, total 161
Graduate students: 17
Publications in 2009: 109 journal aricles, 6 books
SIO RAS PO Division in 2009
Laboratory Head
Ocean-Atmosphere Interactions and Climate Variability S. Gulev
Experimental Physical Oceanography A. Zatsepin
Geophysical Fluid Dynamics G. Reznik
Ocean Optics and Remote Sensing O. Kopelevich
Ocean Acoustics Yu. Chepurin
Noises and Sound Fluctuations in the Ocean A. Vedenev
Internal Waves and Tides E. Morozov
General Ocean Circulation V. Zhmur
Large-Scale Variability of Thermohaline Fields V. Byshev
Continental Discharges and Anthropogenic Impacts P. Zavialov
Turbulence, Mixing, and Microscale Processes V. Zhurbas
Numerical Modeling
Surface Waves and Nonlinear Wave Processes
E. Semenov
V. Zakharov
SIO RAS PO Division in 2009
Ongoing projects of SIO RAS in the seas surrounding Russia
Ongoing projects of SIO RAS in the seas surrounding Russia
1. Antarctic Bottom Water transportthrough SA abyssal channels[E.G.[E.G. Morozov et alMorozov et al..] – ] – multiple publications, multiple publications, 2000-20102000-2010
Vema Channelis a deep passage (4700 m) for AABW in the Rio
Grande Rise (4200 m deep plateau)
The transport of AABW in the Vema Channel is estimated at 3 Sv.
Mean velocities are 30 cm/s;Maximum velocities reach 60 cm/s
Stations occupied in the Vema Channel
Potential temperature across the Vema Channel
The flow is strongly mixed.
The coldest water is
displaced to the eastern wall of
the channel due to the Ekman
friction
Meridional velocity in Vema Channel
Note the southward countercurrent above 4100 m
Velocity profile in Chain F.Z. Total transport through the Chain F.Z. is estimated as 0.1 Sv
“Bifurcation” of the flow while sinking from 4000 m to 4500 m.Agreement with laboratory model experiment.
22. CURRENTS AND WATER MASSES IN THE . CURRENTS AND WATER MASSES IN THE SOUTH ATLANTICSOUTH ATLANTIC
• Golivetz S.V., and M.N. Koshlyakov, Cyclonic Eddies of the Subantarctic Front and Formation of the Antarctic Intermediate Water. Oceanology 43, 305–317. 2003.
• Golivetz S.V., and M.N. Koshlyakov, Eddy Formation at the Subantarcic Front from Sattellite Observations and Formation of the Antarctic Intermediate Water. Oceanology 44, 451–460. 2004.
• Golivetz S.V., and M.N. Koshlyakov, Synoptic Eddies of the Subantarctic and Agulhas Fronts and Generation of the Antarctic Intermediate Water. Oceanology 49, 151–165.
• Gladyshev S.V., M.N. Koshlyakov, and R.Yu. Tarakanov, Currents in the Drake Passage Based on Observations in 2007. Oceanology 48, 821–833, 2008.
• Koshlyakov M.N., S.V. Gladyshev, R.Yu. Tarakanov, and N.I. Ryzhikov, Deep Currents in the Central Part of Drake Passage based on the Data of 2008 Hydrographic Survey. Oceanology, 2010 (in press).
• Tarakanov R. Yu., Circumpolar Bottom Water in the Scotia Sea and the Drake Passage, Oceanology 50 (1), 1–1, 2010.
M.V. Koshlyakov
Abyssal Abyssal and deep water masses at section Drk03and deep water masses at section Drk03
1) 11-15/12/2003 – R/V Akademik Vavilov 2) 8-14/11/2005 – R/V Akademik Ioffe3) 16-20/11/2005 – R/V Akademik Ioffe 4) 11-19/11/2007 – R/V Akademik Ioffe5) 23/10-3/11/2008 – R/V Akademik Vavilov 6) 1-20/1/2010 – R/V Akademik Ioffe
Circulation and upper boundary depth of Circulation and upper boundary depth of Weddel Sea Deep WaterWeddel Sea Deep Water in the Scotia Sea in the Scotia Sea and Drake Passageand Drake Passage
Water exchange in theWater exchange in the Circumpolar Bottom Circumpolar Bottom WaterWater layer across Drk03 and Drk07 sections layer across Drk03 and Drk07 sections based on LADCP measurementsbased on LADCP measurements
Nearly zero total transport of CBW, as well as WSDW seen in three sections (2003, 2007, 2010) may indicate that the Shackleton Ridge has significantly greater influence on the deep and bottom water circulation than previously thought
Hydrographic survey of 2008 in Drake PassageHydrographic survey of 2008 in Drake Passage
Geostrophic currents in the bottom layer, Geostrophic currents in the bottom layer, and virtual pathway of ABW propagationand virtual pathway of ABW propagation
Hypothetic new mechanism of Hypothetic new mechanism of Antarctic Antarctic Intermediate WaterIntermediate Water formation due to the SAF formation due to the SAF cyclonic eddiescyclonic eddies
Example of synoptic SSHExample of synoptic SSH anomalyanomaly in thein the westernwestern SouthSouth AtlanticAtlantic (10.10.200010.10.2000) showing ) showing several cyclonic eddiesseveral cyclonic eddies
Balance componentWater
transport,106 m3/с
Transport of salt content anomaly with reference to the
mean salinity of the box, 105 kg/s
Subantarctic Front cyclones 10.0 –17.6
Subantarctic Front anticyclones –1.4 2.2
Agulhas Front anticyclones 13.3 0.5
South Atlantic Current –17.5 5.3
Currents on the northern boundary of the box
–4.9 –3.1
Mixing on the upper boundary of the box – 8.0
Mixing on the lower boundary of the box – 3.3
Isopycnal mixing on the northern boundary of the box
– 2.8
Isopycnal mixing on the open part of the box boundary along 20°E
– –0.2
Vertical advection on the upper boundary of the box
–1.6 –3.6
Vertical advection on the lower boundary of the box 2.1 2.4
Components of the water and salt balances in the layer of Components of the water and salt balances in the layer of Antarctic Intermediate Water in the South AtlanticAntarctic Intermediate Water in the South Atlantic
Notice: Positive values of the transports of water and salt content anomalies mean flow of water into the box and salinification of water in it. Negative values mean water outflow and freshening. 88
• Zavialov, P.O., A.G. Kostianoy, and O.O. Moller Jr. Tracing Freshwater Discharge Effects on South Brazilian Shelf, Geophys. Res. Letters, doi:10.1029/2003GL018265, 2003.
• Zavialov, P.O., O.O. Moller Jr., and E.D. Campos, SAFARI Cruise: Direct Measurements of Currents on South Brazilian Shelf. Continental Shelf Res., 2002.
33. SHELF CIRCULATION IN SW ATLANTIC, . SHELF CIRCULATION IN SW ATLANTIC, AND ROLE OF LA PLATA DISCHARGEAND ROLE OF LA PLATA DISCHARGE
Analysis of velocity data collected on SWA shelf
Analysis of velocity data collected on SWA shelf
Northward countercurrent on the SWA shelf
SAFARI Cruise (May 2002)
“Zoo” of temperature inversions in La Plata ROFI
“Zoo” of temperature inversions in ROFI
No inversion (away from ROFI)
Typical inversions
SAFARI Cruise: Depth of Tmax, m
40
50
30
15
50
SAFARI Cruise: (Tmax-Tsurf), oC
2
3
4
1
2
SAFARI Cruise: Synthetic TS diagram
Cold season temperature anomalies in La Plata ROFI are 70-80% due to air-sea interactions in the presence of buoyancy controlled stratification - and only 20-30% due to mixing with river waters
THANK YOU
FOR YOUR ATTENTION