ContributionContribution to monitoring the cold water route is

constructed along 3 axes:

1- monitoring transport of the Malvinas Current

2- documenting water mass transformation in the

Argentine Basin (& DP)

3- monitoring transport through Drake PassageMoorings & altimetry

Argo floats launched with parking depths at 400 db and 1000 db to document point 2

Malvinas Current

Current meters moorings in the Malvinas Current below

Jason ground track 026.

Isobaths [500 1000 1500 2000 3000 4000 5000],

positions of SAF and BCF as in Saraceno et al 2004

Blue dots moorings in 1993-1995

Red dots : moorings in 2001-2003

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15-year-long MC transport time series computed from altimetric data and statistical information brought by the two current meters data sets (in black), and from current meter measurements [2001-2003 data set (in red); 1993-1995 data set ((in blue)]. Correlation 0.8)Change in regime : annual cycle after 2000

3

Regression of the windstress curl on

the transport time series at 41°S confidence intervals ----- 15% ___ 5%

on the 13-year-long time series

[1992:2005]

on the first part of the time series

[1992:2000]

on the second part of the time series

[2001:2005]

4

Regression of the windstress curl on

the transport time series at 41°S confidence intervals ----- 15% ___ 5%

on the 13-year-long time series

[1992:2005]

on the first part of the time series

[1992:2000]

on the second part of the time series

[2001:2005]

Circulation around Zapiola Rise• f/h contours over bathymetry

• Velocities from ARGO floats ( pf3900111 et pf3900110)

• order of 20 cm/s at 2000 db

• anticyclonic circulation around ZR

Transport estimate (Saunders and King )

flow over 100 Sv

ZA acts as a blender

Martin Saraceno

Transport

• transport time series (Low pass filtered)

•possible collapses of the anticyclone - impact on mixing.

Moorings presently in the water

10 moorings in the water since Feb 2006: M1 to M10.

Location : below Jason track # 104: 9 Jason cross over points + 1 extra in Yaghan Basin for a better resolution of the stronger flow.

M10 (CM + sediment traps) recovered and redeployed in Dec 2006.

M1 to M10 to be recovered in April 2008 (coll. Korea , KORDI Jae Hak Lee)

Mooring operations 2006-2010coll. LOCEAN/ KORDI/ AWI

2006-200810 moorings in the water since Feb 2006M10 (CM + sediment traps) recovered and redeployed in Dec 2006.M1 to M10 to be recovered in April 2008during Zero-Drake IPY Cruise - E. Farhbach

2008-20095 to 6 moorings to be redeployed in the Yaghan Basin in April 2008:Low frequency mode in SSH in Yaghan BasinM1 to M5 funded (coll. LOCEAN& Kordi)? an extra mooring between M3 and M4 ?

Recovery in September 2009

All operations from R.V. Polarstern

12 floats launched from R.V. Puerto Deseado

March 16, 2005: 6 floats launched in Drake Passage

3 with 400 db parking depth

3 with 1000 db parking depth

July 2 2005: 6 floats launched off the coast of Argentina

3 with 400 db parking depth

3 with 1000 db parking depth

Pseudo-trajectories

April 2007: 2 floats died ( in the same area 36-30W and 38-42S after a life of 11 and 20 months)5 floats left the Argentine Basin (eastward towards South Africa)5 floats still in the Argentine Basin (eastern part) and functionning

12 floats to be deployed again in Drake Passage: from Polarstern in April 2008.

dead

Profiles and seasons.

Positions of the profiles- Color represents seasons.First winter (blue dots) over the Malvinas plateau and

Patagonian slope.Second winter (blue cross) more to the East

No float aboveZapiola Rise

Temperature and salinity as a function n : float 394

1st winter : ventilation over Malvinad Plateau: cooling and freshening until n = 27.6.

Water (= 27.33) in contact with atmosphere (ventilation)

2nd winter:

ventilation until 27.10 only. Float no more in the argentine basin. Left since cycle 48.

T

S

Low frequency variabilityModels with data assimilation Mercator, ECCO ..On-going or funded - proposed? Or to be proposed? Moorings across WBB and SRP (Choke points)