southern ocean observing system cp summerhayes

7/31/2019 Southern Ocean Observing System CP Summerhayes

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The Design of a Southern Ocean

Observing System (SOOS)

With additionalsupport from

C. P. Summerhayes and M. D. SparrowScientific Committee on Antarctic Research (SCAR)

Oceanology International 2010


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Outline

Why are coherent, sustained observations of theSouthern Ocean needed?

What aspects of the Southern Ocean would amonitoring system address, and who would use theinformation?

What is already in place, and what are the gaps?

Where are we in relation to planning and

implementation?


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The Role of Winds There is a pressure and temperature

gradient from tropics to poles;

It creates high pressure at mid latitudes andlow pressure near the poles;

Here we see the Pressure anomaly pattern

(isobars);

Winds run along the contours;

They create a Polar Vortex extending fromsurface to stratosphere;

This strong barrier of winds keeps warm

moist air away.

There is local high pressure at the pole

Icebergs move west along coast in polar

easterlies

J Turner and others

Amundsen Sea Low (ASL) develops because

the continent is off-centre.

This local circulation makes West Antarctica respond differently from East

Antarctica to climate change.

High P

Low P

ASL

Weak high


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Continent cools while peninsula warms

Change in mean

Ann. Temp. C

(1969-2000)

West peninsula

Warm air is brought

in from the north by

Amundsen Sea Low.

Air warms at

0.53 C/decade at

Faraday/Vernadsky

since 1950.

(1.03 C/decade

in winter)

Correlates with

decrease in sea ice.

High P

Low P

Thompson and Solomon 2002


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The need to monitor sea ice

Ozone hole keeps

SO winds 15%

stronger; shieldscontinent from

warm winds and

maintains

sea ice cover

Ozone hole should

disappear by 2070;

IPCC models imply33% decrease in sea

Ice by 2100;

Krill and higher

predators affected;

Increase 1%/decade


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Breeding success and ecological response

Shifts in the penguin population on the

western Antarctic Peninsula are attributed to

changes in precipitation patterns and sea ice.

McClintock, 2008

More snowfall and less sea ice

McClintock 2008


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Responses of Southern Ocean Ecosystems to Change

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

Year

Density(no.m-2)

1

10

100

1000

Atkinson et al, 2004, Nature

As krill decrease, salps increase

!(

!(!(!(!(

!(!(!(

!(!(Change per decade

over twofold decrease

up to twofold decrease

less than 5% change

up to twofold increase

over twofold increase

0 100 200 300 400

Winter ice duration (days)

Krilldensity(no.m-2)

1920s and 1930s

post 1976 era

1000

100

10

1

0.1

As sea ice decreases, krill decrease


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Year

Interannual variability

Years of low krill availability

R

eproductiveoutputindex

1985 1990 1995 2000

-4

-3

-2

-1

0

1

2

4

Antarctic fur seal

Gentoo penguin

Black-browed albatross

Reid & Croxall, 2008

3

El Nio = warm = less ice

W of Antarctic Peninsula =

Implication: will have less production if

Ocean warms and sea ice shrinks.


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S Rintoul, 2001

Circulation complexities beneath the sea ice

Nutrients exported from the Southern Ocean support 75%

of oceanic primary production north of 30S (Sarmiento et al.)


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Global reach of the Southern Ocean

Lumpkin and Speer (2006)

Critical part of the global thermohaline circulation


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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

Boning et al, 2008


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Warm ocean makes glaciers melt faster in Antarctica

potential impacts on global sea level

NOCs Autosub3

Changes in thickness of the

Antarctic ice sheet - Zwally et al., 2005

Face of the Pine Island Glacier, 2009:Antarcticas fastest-melting glacier.

Ocean temperature under the glacier

from Autosub3; Pierre Dutrieux (BAS)


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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 Qur etc)?


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Aragonite pteropod

- planktonic marine

snaila major food

in the Southern Ocean

(N. Bednarsek, BAS)

Acidification of the Southern Ocean% saturation in aragonite;

blue = undersaturated;

dissolution may begin

Ocean Carbon-Cycle Model Intercomparison Project (OCMIP-2) models (adapted from Orr et al., 2005)

Increasing acidity; Feely 2008

Ocean takes up 35% of

human emissions;

Southern Ocean takes up40% of that

%


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Outline


What aspects of the Southern Ocean would amonitoring system address, and who would use the

information?



implementation?


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SOOS is being designed to address sixkey challenges

Role of Southern Ocean in global freshwater balance

Stability of Southern Ocean overturning

Stability of Antarctic ice sheet and futurecontribution to sea-level rise

Future of Southern Ocean carbon uptake

Future of Antarctic sea ice

Impacts of climate change on Antarctic ecosystems


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Top-level challenges used toidentify key variables to bemeasured.

and theplatforms that canmake them.


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Potential users of a SOOS include

Research community

Resource managers (including CCAMLR etc)Convention on Conservation of Antarctic MarineLiving Resources

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.


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Outline



information?



implementation?


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Repeat

hydrography

~5-10 yr interval withcarbon

Many lines already signedup to; some are not.


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(Figure in need of updating)

Ship-of-opportunity lines

XBT/XCTD/ADCP/pCO2etc

Often several occupations

per year.


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Moorings in strategic locations

(Background from Orsi et al., 1999)

Proposed mooringarray to sampleAABW export sites,to measure thelower limb of theMOC.

Most locationssigned up for, buthow to sustain?

Contours show

inventory of CFC-11 in the densitylayer correspondingto AABW


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Reasonable coverage around most of ACC; data density drops in subpolar regions.

Southern Ocean Argo


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Array of sound sources deployed totrack modified Argo floats under iceduring IPY. Who will sustain these?

Also needed in Ross Sea who willdo this?

Temperature plot and velocity fieldderived from profiling float data

(AWI; Fahrbach et al)

Argo-under-ice


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Different spatio-temporal samplingavailable from CTD tagging of marinemammals.

Species can be targeted to access specificicy regions.

Invaluable data for both ecological andh sical sciences.

Photo Lars

Boheme


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Circulation, processes and changebeneath ice shelves

Locations of currentor planned drillholes through ice

shelves to sampleocean water in iceself cavity.

Many of these have

firm commitments,but how to sustain?


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The Survey covers>70 % of theSouthern OceanOctober to April

135,000 nautical

miles of data havebeen collected since1991

This represents morethan 27,000 samples,

200+ taxa+environmental data

Approximately40-50 tows each year>4,000 samples p.a.5 n-mile resolution

Australia, Japan, NZ,Germany, UK, USA,Russia

Continuous Plankton Recorder Tows 1991-2008

(Hosie et al)


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What observing

system elementsare 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.


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Gaps

Ice-covered regions still poorly sampled, despite progress

Deep ocean below depth of Argo (2km)

Ocean in ice shelf cavities poorly observed

Seabed is poorly observed (benthic communities etc)

Non-physical measurements rarely routinely made (need other

sensors for Argo etc)

etc


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Outline



information?



implementation?


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SOOS Timeline - plan

August 2006: Initial scoping workshop, Hobart

October 2007: Workshop in Bremen. Planning andwriting tasks assigned

July 2008: St. Petersburg progress review meeting

September 2009: Venice progress review meeting;OceanObs SOOS CWP

March 2010: Full draft SOOS plan on www for final

open consultation

June 2010: Launch at IPY Conference, Oslo

July 2010: Commence implementation...


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Implementation needs:-

Continued commitment from those already involved

SOOS starting design is in place, and feasibility wasdemonstrated during IPY. But needs maintaining and building-up, in financially difficult times

More nations and institutes to participate

The vast majority of the Southern Ocean belongs to noindividual nation

All nations with an interest/capacity are needed to contribute can POGO help with this?

Precise knowledge of what is needed

Quantified targets for the data density/spatial coveragerequired for each parameter

Model analyses needed for this (BAS/NOCS?)


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Vision

Design of SOOS will change as science and technologyprogresses

Visions for 5-10 years and 30 years already in SOOS plan, butwill evolve

Need to use SOOS-derived science outputs to refine sciencedrivers

Need to drive technology developments to maximise SOOSeffectiveness, not just adopt them as they happen

e.g. ice-capable gliders, enhanced autonomous technologyfor roughest seas etc.

Impact

Need to be able to demonstrate the value that SOOS brings,scientifically, economically and societally (how? who?)


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Management

SOOS Implementation Panel, drawn from SCAR/SCOR andCLIVAR groups, and other key organisations

Will oversee links and synergies with e.g. GOOS, GCOS,CAML, WCRP, SCAR, SCOR, POGO etc

Strategic data policy and management (SOOS portal, or other?SCAR SCADM, AAD?)

Secretariat (AAD?)

Commitment of resource

SOOS requires people and institutes to commit time and effort $OO$ requires long-term investment how to achieve?


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Ask not whatSOOS can do

for you.

More information:-

www.clivar.org/organization

/southern/expertgroup/SOOS.htm


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Thank you for your attention

southern ocean observing system cp summerhayes

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