CLIVARCliCSCAR Southern Ocean Panel

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CLIVAR/CliC/SCARSouthern Ocean Panel
Nico Caltabiano, on behalf of the panel
NOCS, 13-14 March 2008
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What observing systems are already in place?
http//argo.ocean.fsu.edu/
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What observing systems are already in place?
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What observing systems are already in place?
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DIMES Fieldwork Overview
DIMES will obtain multiple, concurrent measures
of mixing and upwelling and their driving
processes in the SE Pacific and SW Atlantic
sectors of the ACC.

• Experimental components
• 8 cruises 5 U.S.-led, 3 U.K.-led in 3.5 years
• Mid-depth tracer release
• Turbulence (microstructure) measurements
• Internal wave and eddy (finestructure)
  measurements with profiling (EM-APEX) floats
• Eddy measurements with isopycnal floats
  U.S.-led
• Mooring cluster to measure eddy - internal wave
  coupling U.K.-led

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DIMES Fieldwork Tracer Release
We will release a tracer on a 1300-m-deep
isopycnal to measure the integrated rates of
mid-depth mixing and upwelling.

• Experimental components
• 8 cruises 5 U.S.-led, 3 U.K.-led in 3.5 years
• Mid-depth tracer release
• Turbulence (microstructure) measurements
• Internal wave and eddy (finestructure)
  measurements with profiling (EM-APEX) floats
• Eddy measurements with isopycnal floats
  U.S.-led
• Mooring cluster to measure eddy - internal wave
  coupling U.K.-led

Pilot simulation of the DIMES tracer release with
an eddy-resolving numerical model (2 years after
release)
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DIMES Fieldwork Micro- and Finestructure
We will collect 300 full-depth profiles of
temperature, salinity and velocity microstructure
with specialized profilers during three summer
cruises, and 4500 profiles of finestructure with
a fleet of autonomous floats profiling year-round
in the upper 1500 m. These will help us to assess
the distribution of mixing and upwelling, and
their driving processes.

• Experimental components
• 8 cruises 5 U.S.-led, 3 U.K.-led in 3.5 years
• Mid-depth tracer release
• Turbulence (microstructure) measurements
• Internal wave and eddy (finestructure)
  measurements with profiling (EM-APEX) floats
• Eddy measurements with isopycnal floats
  U.S.-led
• Mooring cluster to measure eddy - internal wave
  coupling U.K.-led

Turbulence profiler
EM-APEX float
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DIMES Fieldwork Mooring cluster
We will deploy a cluster of moored current
meters, MMPs, a rising microstructure profiler,
an ADCP and a PIES to obtain temperature,
salinity and velocity profiles in Drake Passage
for 2 years. These will allow us to measure the
set of physical processes coupling
geostrophically balanced and unbalanced motions
in the ACC.
Bathymetry (colours), satellite altimetry ground
tracks (black lines), and location of Drake
Passage moorings (red circles).

• Experimental components
• 8 cruises 5 U.S.-led, 3 U.K.-led in 3.5 years
• Mid-depth tracer release
• Turbulence (microstructure) measurements
• Internal wave and eddy (finestructure)
  measurements with profiling (EM-APEX) floats
• Eddy measurements with isopycnal floats
  U.S.-led
• Mooring cluster to measure eddy - internal wave
  coupling U.K.-led

Polar Front
Lateral mooring
Central mooring
Rising microstructure profiler
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Southern Elephant Seals as Oceanographic Samplers
Coverage from SMRU seal-tag CTD data during 2004/5
(Boehme, Fedak et al., SMRU)
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Activities over the past year

• Participation in IPY (CASO, SASSI)
• SOOS meeting

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SOOS Timetable

• 29 Feb. 2007 Extensive outline of SOOS document
• 31 May 2008 Completion of writing assignments
  for different parts of the SOOS document
• 5-11 July 2008 Presentation of the draft
  document, and discussion, at expanded meeting of
  the SCAR/SCOR Oceanography Expert Group, and as
  part of the SCAR/IASC Ocean Science Conference
  (St Petersburg, Russia) to obtain further
  feedback
• 30 September 2008 Inclusion of feedback to
  finalise document
• 31 October 2008 Publish the document

http//www.clivar.org/organization/southern/expert
group/SOOS.htm
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Future meetings

• Panel meeting (Feb 2009, Melbourne, Australia)
• SOOS evaluation
• Carbon science within SOOS
• Climate/Carbon process study development
• Report of state of southern climate system
  variations and key modes
• Gaps in climate modeling
• Reanalysis and fluxes in Southern Ocean/Ice
  system
• The SCAR/IASC Open Science Conference (July 2008,
  St Petersburg, Russia)
• Ocean in High CO2 World (Oct 2008, Monaco)

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Indices

• Stratification indices
• At nominal 35S locations in the South Atlantic,
  South Pacific, and Indian Ocean
• AA peninsula and time-series stations in polar
  basins but significantly distant from the source
  areas ?- Weddell Gyre ?and Ross Gyre
• Ice indices
• Satellite sea-ice extent thickness on repeat
  tracks
• Grounding line index (InSAR mission)
• Upper Ocean
• Shelf salinity in Ross Sea
• Mixed layer depth and salinity
• Transport indices
• AA continental slope at 3 locations and northern
  Drake Passage

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Key points

• A major CLIVAR Southern Ocean science goal is to
  quantify freshwater fluxes, and to achieve that
  we need accessibility of diverse data already in
  various pipelines to re-analysis efforts
• IPY-period synthesis
• SO Indices