The Southern Ocean Observing System SOOS

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The Southern Ocean Observing System (SOOS)
With additional support from
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Global reach of the SO
Lumpkin and Speer (2006)
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Ocean heat storage
84 of global warming since 1955 is found in
the ocean
OCEAN
LAND
ICE SHEETS
ATMOSPHERE
SEA ICE
GLACIERS
Levitus et al., 2004
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Change in zonally-integrated ocean heat content
since 1955 is largest in the southern oceans
Levitus et al., 2004
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Ocean uptake of carbon dioxide
Sabine et al., 2004
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Saturation of the SO CO2 sink?
Le Quere et al. 2007
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Ocean acidification/saturation state
Orr et al., 2005
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Warming in ACC, no change in transport?
Comparison of Argo CTD data along streamlines
shows warming across the Southern Ocean,
strongest on southern flank of ACC. Southward
shift of isopycnals BUT little change in tilt,
hence no change in upwelling (unlike in IPCC
models).
Boening et al., 2008
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Warmer ocean drives more rapid basal melting of
PIG
Fast Recession of a West Antarctic Glacier E. J.
RIGNOT Satellite radar interferometry
observations of Pine Island Glacier, West
Antarctica, reveal that the glacier hinge-line
position retreated 1.2  0.3 kilometers per year
between 1992 and 1996, which in turn implies that
the ice thinned by 3.5  0.9 meters per year. The
fast recession of Pine Island Glacier, predicted
to be a possible trigger for the disintegration
of the West Antarctic Ice Sheet, is attributed to
enhanced basal melting of the glacier floating
tongue by warm ocean waters. Science 24 July
1998Vol. 281. no. 5376, pp. 549 - 551
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Freshening of AABW
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Why do we care if SO changes?

• Potential for positive feedbacks influencing
  global climate
• Sea ice albedo
• Carbon uptake
• Thermohaline circulation
• Sea-level rise
• Impact of acidification on ecosystems
• Impact of climate change on ecosystems (warming,
  freshening, ?mixed layer, ?light, ?circulation,
  ?sea ice, ?winds)

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Users of a SOOS

• Research community
• Resource managers
• Policy makers (when is it time to act? What are
  the consequences of not acting?)
• IPCC
• Local planners (sea-level rise)
• Antarctic tourism
• Shipping operations
• Weather and climate forecasters
• Education
• Community

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SOOS Structure

• First stage is to produce a document that
  demonstrates
• why sustained observations are needed in the
  Southern Ocean and what science/policy questions
  they address,
• what mix of observations are required to address
  these questions,
• what is presently done and possible,
• a vision for the future

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Example key science questions

• Role of Southern Ocean in global freshwater
  balance
• Stability of Southern Ocean overturning
• Stability of Antarctic ice sheet and future
  contribution to sea-level rise
• Future of Southern Ocean carbon uptake
• Future of Antarctic sea ice
• Impacts of climate change on Antarctic ecosystems
• Ecosystem response to acidification

In order to answer key Science questions need to
measure
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Key scientific challenges
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(No Transcript)
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Scope of the SOOS

• Space
• circumpolar
• Subtropical Front to coast / ice sheet grounding
  line
• Time
• days to decades (longer-term proxies from ice and
  sediment cores are critical, but lie outside of
  SOOS?)
• Domain
• sea surface to sea floor (including bathymetry)
• Ocean sea ice
• Include air-sea flux, not upper atmosphere
• Include sub-ice shelf cavity, not glacial ice
  itself
• Feasibility/readiness
• Consider READY NOW and 10 YEAR VISION
• Consider both MINIMAL and IDEAL

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Scope of the SOOS (2)

• Discipline
• Physics (ocean circulation and sea ice)
• Biology and Ecology (microbes to whales?)
• Biogeochemistry
• Bathymetry
• Surface meteorology
• Models Emphasis is on sustained observations,
  but modelling plays a key role in
• system design
• interpolation and interpretation of sparese
  observations
• demonstrating utility of SOOS (eg initialisation
  of climate models)
• Data center concept for models could be very
  powerful (eg PCMDI)

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Some examples of observing systems already in
place
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Hydrography CTD/XBT/CO2 5-10 yr interval
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Argo
http//argo.ocean.fsu.edu/
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Sound sources (red deployed by Keith Nichols,
BAS, black in the water, blue in plan) and
floats (green floats)in the Weddell Sea west of
the Greenwich Meridian. The extension of the
network will occur in cooperation with Svein
Osterhus frorm the Bjerknes centre in Bergen
(Norway)
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Southern Elephant Seal with CTD tag
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Interannual variability in Movement Patterns
2006
2005
Costa et al unpublished
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CPR Tows 1991-2008
The Survey coversgt70 of the Southern
Ocean October to April
Approximately40-50 tows each year gt4,000 samples
p.a. 5 n-mile resolution
135,000 nauticalmiles of data havebeen
collected since 1991
This represents morethan 27,000 samples, 200
taxa environmental data
Australia, Japan, NZ, Germany, UK, USA, Russia
Hosie et al
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• Satellites (e.g. SeaWiFS, Cryosat)
• South Atlantic Monitoring System
• Current meter arrays sea level monitoring
• Sediment trap moorings
• Underway measurements (e.g. CO2 , Salinity)
• Sea ice thickness snow cover drift
• Etc.

What observing systems are already in place?
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Gaps in the observing system in the Southern
Ocean region

• We are not yet able to routinely monitor the
  characteristics of the ocean in the seasonally
  and permanently ice-covered region (despite under
  ice Argo, ice-tethered profilers and animal
  -borne sensors)
• In order to properly understand the processes
  that contribute to global change (e.g.
  understanding the MOC) our monitoring efforts
  need to be extended to the deep ocean
• increase Argo depth floats
• Moorings, gliders

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Gaps in the observing system in the Southern
Ocean region

• Routine measurements beneath the ice shelves
  required to understand how the ocean/ice-shelf
  interaction will change as the climate alters,
  and what the impacts may be for deep and bottom
  water formation and the global overturning in the
  ocean
• Development of new sensors and methodologies is
  key (e.g. biogeochemistry sensors to Argo floats,
  automated under ice measuring systems, technology
  to study the long-term impact of seasonal ice
  cover on pelagic and benthic communities)

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Gaps in the observing system in the Southern
Ocean region

• Need to sample the polar oceans routinely and
  cost-effectively with an appropriate level of
  coverage to capture the main oceanographic,
  meteorological, cryospheric and ecosystems
  processes taking place there that contribute to
  global change

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Goals of St Petersburg meeting

• To get specific about what SOOS should look like
• Speakers asked to
• Present strawman plans for each component of SOOS
  (physics, ecosystems, cryosphere)
• Be specific (e.g. lines on maps, sensors, )
• Justification for the observations
• Identify dependencies on other components of SOOS
• Identify key gaps
• Draft recommendations
• Agree on next steps needed to complete plan

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Timeline

• July 5-7 St Petersburg meeting. Writing
  assignments
• August 14 Writing assignments received
• August 22 Complete first draft circulated to
  co-authors and Expert Group
• September 4 Comments received
• September 14 Complete draft circulated to
  community for comment
• October 14 Comments received.
• November 14 Publish report.

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Thank you
http//www.clivar.org/organization/southern/expert
group/SOOS.htm