1. The Southern Ocean Observing System (SOOS)
With additional support from

2. Talk Outline
Why are coherent, sustained observations of the Southern Ocean needed?
Who would use them?
What aspects of the Southern Ocean would a monitoring system address, and how?
What is already in place, and what are the gaps?
Where are we in relation to planning and implementing the observing system, and what is next?
How would a SOOS link to other international efforts?

3. Talk Outline
Why are coherent, sustained observations of the Southern Ocean needed?
Who would use them?
What aspects of the Southern Ocean would a monitoring system address, and how?
What is already in place, and what are the gaps?
Where are we in relation to planning and implementing the observing system, and what is next?
How would a SOOS link to other international efforts?

4. Global reach of the Southern Ocean
Reasons for a SOOS -
Lumpkin and Speer (2006)
Critical part of the global thermohaline circulation

5. Change in zonally-integrated ocean heat content
since 1955 is largest in the southern oceans
Levitus et al., 2005
Important term in global heat budget, but Southern Ocean is still undersampled compared with rest of World Ocean

6. Boening et al., 2008

7. Warming in ACC, no change in overturning?
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 7

8. Freshening of AABW 8

10. The Weddell gyre circulation and the area of observations carried out during WECCON and CASO
Fahrbach, AWI

11. Area of WSBW on the transect decreased by 25%
from 1992 to 2008
1992
2008
Fahrbach, AWI

12. Bottom melting: heat source and effect of pressure.
Mode 1: Thermohaline circulation induced by sea ice formation and drainage of dense saline water. Melting point decreases as much as 1oC due to oC/dbar-1
Mode 2: Direct inflow of intermediate-depth ‘warm’ water from the slope-front region (e.g. Circumpolar Deep Water intrusion through deep troughs).
Mode 3: Ice-front interactions (tidal pumping, coastal currents)
AASW
CDW
ISW
Jacobs et al., 1992
Ice shelf water may refreeze to form marine ice, or sink to participate in the formation of Antarctic bottom water, which regulates global climate.
Mode 1 dominates for large ice shelves in the Weddell, and Ross seas.
Mode 2 melts large volumes of ice where deep water has access to glacier grounding lines, e.g. Amundsen Sea.

13. Conclusions
Ice shelf melting controls > 50% of the ice sheet/ice shelf mass balance.
This neglects ice-front sub-aqueous melting.
Low melt on large ice shelves (far from CDW), Queen Maud Land, East Peninsula.
High melt on West Peninsula (CDW), Amundsen, Bellingshausen sea (CDW), Wilkes Land (?).
Quadratic dependence on temperature where CDW fuels high melt.
Elsewhere, linear relationship might still hold but not enough ocean temperature data near GL.

14. Antarctica loss increased from -112 to -196 Gt/yr
EAIS 61 Gt/yr
WAIS 59 Gt/yr
WAIS 60 Gt/yr
WAIS 50 Gt/yr
AP 45 Gt/yr
AP 46Gt/yr
Antarctica loss increased from
-112 to -196 Gt/yr

16. Ocean uptake of carbon dioxide
Sabine et al., 2004
Southern Ocean a key region for uptake of anthropogenic CO2 – but is the carbon sink weakening (Le Quéré etc)?

17. Le Quere et al., 2007

18. Why a SOOS (continued…) ?
Krill stocks in key parts of the Southern Ocean are in steep decline… need to understand why, and the implications.
(Atkinson et al., Nature, 2004)

19. Why a SOOS (continued…) ?
Changes in Southern Ocean temperature and circulation could have strong impacts on West Antarctic ice sheet (and hence global sea level)
Nutrients exported from the Southern Ocean support 75% of oceanic primary production north of 30S (Sarmiento et al.)
The Southern Ocean includes some of the most productive and unique marine ecosystems on Earth
etc…

20. 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)

21. Talk Outline
Why are coherent, sustained observations of the Southern Ocean needed?
Who would use them?
What aspects of the Southern Ocean would a monitoring system address, and how?
What is already in place, and what are the gaps?
Where are we in relation to planning and implementing the observing system, and what is next?
How would a SOOS link to other international efforts?

22. Potential users of a SOOS include …
Research community
Resource managers (including CCAMLR etc)
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
Etc.

23. Talk Outline
Why are coherent, sustained observations of the Southern Ocean needed?
Who would use them?
What aspects of the Southern Ocean would a monitoring system address, and how?
What is already in place, and what are the gaps?
Where are we in relation to planning and implementing the observing system, and what is next?
How would a SOOS link to other international efforts?

24. Scope of the SOOS Space: circumpolar
Subtropical Front to coast / ice shelf 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, 5-10 YEAR VISION and BY 2030
consider both MINIMAL and IDEAL

25. Scope of the SOOS 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 sparse observations
demonstrating utility of SOOS (eg initialisation of climate models)

26. Talk Outline
Why are coherent, sustained observations of the Southern Ocean needed?
Who would use them?
What aspects of the Southern Ocean would a monitoring system address, and how?
What is already in place, and what are the gaps?
Where are we in relation to planning and implementing the observing system, and what is next?
How would a SOOS link to other international efforts?

27. Some examples of observing system elements already in place…

28. Hydrography CTD/XBT/CO2 5-10 yr interval
Hydrography still the mainstay

29. Argo http://argo.ocean.fsu.edu/
Note should use most up to date version of this figure (site is down today )

30. Sound sources deployed in Weddell Sea to track modified Argo floats under ice
Ensonification of certain areas (e.g. Weddell Sea) allows under ice tracking of floats

31. Temperature and current field in the area of Maud Rise derived from floats – Olaf Klatt
Geschwindigkeit und Temperatur in 800m Tiefe. geglättet

32. Tagging of marine mammals (SEaOS etc)
These guys are also very helpful…

33. Elephant seal oceanography
Mapping the ocean underneath the sea ice for the first time (Charassin et al., PNAS, 2008).

34. SEaOS: Number of profiles
SODB: 10513
Argo: 19463
SEaOS: 22230
SEaOS especially useful as can obtain data under ice.
Accuracy of T now around C
Courtesy L. Boehme

35. Mapping high latitude fronts

36. Sea ice formation from salinity change
Charassin et al., PNAS, 2008

37. Near circumpolar coverage from elephant seal data …
Use of seals…Large increase in data, especially under ice! Important for both ecosystems and physics…
Other species can be targeted to access specific icy regions.
Invaluable data for both ecological and physical sciences.

38. Continuous Plankton Recorder Tows 1991-2008
The Survey covers >70 % of the
Southern Ocean
October to April
Approximately tows each year
>4,000 samples p.a.
5 n-mile resolution
135,000 nautical miles of data have been collected since
1991
This represents more than 27,000 samples,
200+ taxa
+environmental data
SCAR CPR study – Zooplankton observing system
Australia, Japan, NZ,
Germany, UK, USA,
Russia
Hosie et al

39. What observing system elements are already in place?
Above plus:-
Satellites (e.g. SeaWiFS, Cryosat)
Current meter arrays
Tide gauge network
Sediment trap moorings
Underway measurements (e.g. CO2 , Salinity…)
Sea ice thickness; snow cover; drift
Etc….
What observing system elements are already in place?
Many different observations in place, but many gaps and could be more coordination between disciplines…

40. Gaps in the observing system in the
Southern Ocean region
Ice-covered regions still poorly sampled, despite progress
Deep ocean below depth of Argo
Ocean in ice shelf cavities
Seabed is poorly observed (benthic communities etc)
Non-physical measurements rarely routinely made (need other sensors for Argo etc)
etc

41. 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)
This is not least because it is thought that a steadily warming ocean may degrade ice shelves and glacier snouts from beneath, thinning them so that they break up as did the Larsen ice shelf in 2002.The break-up of such ice shelves removes the dam that slows glacier discharge from the interior, thus having an effect on how rapidly inland ice can drain to the sea and raise sealevel

42. 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

43. Talk Outline
Why are coherent, sustained observations of the Southern Ocean needed?
Who would use them?
What aspects of the Southern Ocean would a monitoring system address, and how?
What is already in place, and what are the gaps?
Where are we in relation to planning and implementing the observing system, and what is next?
How would a SOOS link to other international efforts?

44. SOOS Timeline August 2006: Initial scoping workshop, Hobart
October 2007: Workshop in Bremen. Planning and writing tasks assigned
July 2008: St. Petersburg progress review meeting
January 2009: Make draft SOOS planning document available to community for comment
February 2009: Comments received
March 2009: Publish report
April 2009: Commence implementation...

45. SOOS Structure
SOOS planning document (to go out to the community for comment) will outline the aspects discussed here:-
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 what is possible,
a vision for the future (in 5-10 years; and by 2030)

46. SOOS designed to address six key challenges
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
Guided by Science….

47. In report we will use a two layer table system – firstly identify what variables we need to measure…(table still draft)
(*draft*)

48. Then what platforms are required to measure variables (note table is still draft)

49. Strawman Southern Ocean Observing System
Initial SOOS consists of coordination/enhancement of extant elements, as discussed, including:-
Repeat full-depth hydro/tracer sections along WOCE lines
Profiling floats, open ocean and under sea ice
Sensors on marine mammals
Sea ice observations
Ocean-ice shelf interaction
Surface meteorology observations
Surface and sea-ice drifters
Ecological monitoring …

52. CFC-11
Orsi et al., 1999

53. Strawman Southern Ocean Observing System
5-10 years and 2030 vision (see planning document for details) as previous, but including:
Enhanced profiling floats with additional sensors, depth range and longevity.
Cost-effective time series stations, using data capsule technology and expendable moorings.
Supply/research ships doing routine surveys/sections on way into Antarctic bases
Network of integrated fast ice “mass balance” stations
A network of ice-capable gliders
etc

54. Strawman Southern Ocean Observing System
SOOS coordination group to oversee the implementation of the observing system, plus:-
Relevant data archaeology
Delivery of Southern Ocean climate information
Modeling
Identification of remote sensing needs
Identification of key gaps requiring enhanced process understanding
Array design studies
Technology development requirements …

55. Strawman Southern Ocean Observing System
As an example: recommended repeat hydrography, with countries committed or interested in occupying the lines.
Again, note draft only

56. Talk Outline
Why are coherent, sustained observations of the Southern Ocean needed?
Who would use them?
What aspects of the Southern Ocean would a monitoring system address, and how?
What is already in place, and what are the gaps?
Where are we in relation to planning and implementing the observing system, and what is next?
How would a SOOS link to other international efforts?

57. SOOS Implementation
Buy-in of international programmes of relevance to SOOS (SCAR, SCOR, GOOS, CAML, POGO, WCRP,JCOMM, GCOS...), leading environmental agencies and other key players.
Links between SOOS, research programmes and international organisations will be effected by the SOOS coordination group.
Group will also oversee coordination of field activities; development of a funding strategy; etc.

58. SOOS and POGO
POGO was one of the initial supporters and sponsors of SOOS; continuing endorsement is needed.
POGO community can help by circulating details of the planning document and sending feedback to Steve Rintoul and/or Mike Sparrow
To be successful, SOOS will need all nations with current active interests in the Southern Ocean to participate, and to draw new nations in – POGO can stimulate this.

59. More information … (

60. A final word…
“Many more voyages of discovery are also needed, especially in the vast expanses of the southern seas that remain relatively unexplored”
“Troubled Waters”
The Economist, Jan 3rd 2009