Diapositive 1

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Emerging Arctic Ocean Cimate Science Observing
Systems Issues by Jean-Claude Gascard CNRS
senior scientist Coordinator of the IP Damocles
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Sept 1979
Sea ice extent minimum
Sept 2005
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Four-day sea-ice drifts from April 30 until May
3, 2002 deduced from Quickscat (R. Ezraty and
J-F. Piollé, user manual ref C2-MUT-W-06-IF,
April 2003)
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Time series of arctic perennial sea-ice from
weekly ERS scatterometer. Backscatter maps and
intercomparison with passive microwave data
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Trend in modelled ice thickness from 1987 to 1999
in meter per year (Rothrock et al 2003. GRL)
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Mean sea-ice draft has decreased by 1.3m in most
of the deep water portion of the Arctic
Ocean (3.1m during 70s compared to 1.8m during
90s) according to D.A. Rothrock, Y. Yu and G.A.
Maykut (GRL Vol 26, NO. 23, december 1,
1999) What changes in arctic heat fluxes would
cause the observed change in sea-ice thickness
? a/ a 4 W/m2 increase in ocean flux from a
nominal value of 2 to 4 W/m2 (heat advected via
the atlantic layer and/or via the cold halocline
layer ?) b/ a 13 W/m2 increase in poleward
atmospheric heat transport from a nominal value
of about 100W/m2 (heat advected by storms and
changes in storm tracks ?) c/ a 23 W/m2 increase
in downwelling shortwave radiation from a
nominal value of about 200W/m2 (and/or increase
in length of the melting season?) These changes
are significant but they are at the threshold of
our actual observational capabilities.
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The Arctic Oscillation as seen by Sea Level
Pressure measurements and Sea-Ice drifts during
the International Arctic Buoy program over the
past 20 years and corresponding respectively to
low and high AO indices.
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Amplification due to synchronicity of the
so-called decadal Arctic Oscillation (AO) and the
inter-decadal low frequency (LFO) North Atlantic
Oscillation (Polyakov and Johnson
2000) characterised by a/ a decrease in sea
level pressure (Walsh et al 1996) b/ an increase
in surface air temperature (Rigor et al 2000) c/
changes in wind regime from anticyclonic to
cyclonic (Proshutinsky et al 1999) and related
ice exports A Climate Oscillation or a Shift ?
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The US Arctic, Alaska and the Bering Sea have not
been spared from the impacts of Arctic climate
change Unprecedented minima of Sea-Ice extent
have occurred in the Pacific Arctic during the
three most recent summers It was hypothesized
that the highly positive state of the Arctic
Oscillation index from the late 1980s to the
late 1990s was the proximate driver for these
observed changes but the current paradox is that
many Pacific changes are continuing despite the
observation that climate indices such as the AO
were negative or neutral for the last 6 of 9
years May the Pacific Arctic Region or even the
entire Arctic have shifted to a new climate
state ?
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One more step toward a warmer Arctic By Polyakov
et al (23 co-authors) GRL Vol 32, September 9,
2005
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Profils verticaux de température et de salinité
observés davril à juin 2002 (April-June) entre
89N et 87N
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Still major controversy and/or conflicting
statements Arctic Sea-Ice thickness remained
constant during the 1990s by Peter Winsor GRL
Volume 28, Number 6, March 15, 2001 Brines
formation versus Open Ocean deep convection for
ventilating the deep Ocean during stadials and
interstadials respectively Trond Dokken and
Eystein Jansen NATURE Freshening and cooling of
the Atlantic water masses as the main driver of
the global thermohaline circulation bypassing
winter deep convection Cecilie Mauritzen
DSR Nature and Origin of the Denmark Strait
Overflow A new path for the Denmark Strait
Overflow water from The Iceland Sea to Denmark
Strait S. Jonsson and H. Valdimarsson GRL Vol 31,
February 10, 2004 One more step toward a warmer
Arctic By Polyakov et al (23 co-authors) GRL Vol
32, September 9, 2005
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1/ Is the Arctic system moving to a new
state? 2/ Is the Arctic Climate as sensitive to
global changes as models suggest? 3/ To what
extent may the Arctic Sea Ice cover retreat or
even disappear in this century? 4/ What are the
consequences of a drastic retreating ice cover
for the Arctic? 5/ What are the most
consequential links between the Arctic and the
Earth system? 6/ To what degree are recent
changes in the Arctic Climate of natural or
anthropogenic origin? 7/ What are the relevant
processes and how well they are represented in
global models? 8/ What is the predictive
capability for the Arctic and what are the
optimum components of an integrated forecasting
system on seasonal and climate scale?
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What are the relevant processes and how well they
are represented in models ? 1/ Brines formation
and fates and its role in deep ventilation 2/
Deep convection and deep water formation
(Submesoscale Coherent Vortices) Are Brines the
dominant mode for ventilating the deep ocean
during Ice Ages in contrast with Deep Ocean
convection being dominant during interglacial
periods? 3/ Atmospheric Boundary Layer (
Inversion layer decreasing ?) 4/ Cold halocline
(retreating?) 5/ Feedbacks (0
Thresholds (freezing and melting). 7/ First
Year Ice/Multi Year Ice. Deformed/Undeformed
Ice 8/ Thermohaline circulation (freshening and
cooling) 9/ Overflows (origins, structure and
composition) 10/ Storm tracks. Polar Lows ?
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77.57N 18.40E
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ESOP II Float 2 horizontal trajectory at 250 m
depth from November 4, 1996 until August 31,1997
Days
Float 2 time series of zonal and meridional
displacements (X,Y) and velocities (U,V)
Days
Float 2 pressure and temperature time series
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N/f RV/ JOHAN HJORT, May 1997
N/f RV/ JOHAN HJORT, June 2003
N/f
N/f
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SCV
SCV
Greenland
ESOP II
Gyre
SCV
Horizontal trajectories for 5 floats (240 m to
530 m depths) March - August 1997.
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DAMOCLES
Developing Arctic Modelling and Observing
Capabilities for Long-term Environment Studies
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GERMANY AWI C. Lüpkes E.
Fahrbach U.Schauer R.
Gerdes A.
Beszczynska-Moller C. Haas
M. Rutgers van der Loeff UB
G. Heygster C. Melsheimer
L. Kaleschke UNIHAM- B. Brümmer J.
Meincke OASYS F. Kauker M.
Karcher FastOpt T. Kaminski R.
Giering
UNITED KINGDOM CEFAS- S. Dye
R.R. Dickson UCAM-DAMTP P. Wadhams UCL-
S. Laxon POL- C. Hughes UREADES K. Haines SAMS-
J. Wilkinson ATL A. Smerdon S.
Caine
FINLAND FIMR- J. Haapala J.
Launianen B. Rudels T.
Stipa UoL- P. Kankaanpää FMI- T. Vihma
C. Fortelius HUT- M. Vainio
DENMARK DMI- S. Andersen R. Tonboe
R. S.Gill DTU- P. L. Toudal DNSC- R. Forsberg
BELGIUM IPF- A. Huber N.Johnson-Amin
POLAND IOPAN J. Piechura W.
Walczowski P. Schlichtholz

RUSSIA SRC AARI- S.Priamikov Sokolov Ashik SIO
S. Pisarev Y. Egorov
D. Darbinian S. Vavilov N.
Dikareva
DAMOCLES
NORWAY NERSC O. Johannessen S.
Sandven H. Drange H. Sagen
K. A. Lisaeter Met.no H.Schyberg
C. Mauritzen
O. Godoy
J.Debernard
NPI- E. Hansen S. Gerland IMR
H.Loeng UiB P. M. Haugan K. Arild
Orvik I. Fer UNIS F. Nilsen CICERO G.
Eskeland A. Aaheim NAXYS J.
Abrahamsen Aanderaa K. G. Frøysa
GREECE FORTH- E. Skarsoulis
FRANCE UPMC J. C. Gascard P. Bouruet-Aubertot F.
Vivier H.Lemoine E.Billi IFREMER R. Ezraty
G.Loaec CNRS/LGGE J. Weiss UdS- D. Marsan
J.P. Metaxian MSI- P. Brault CPX C. de
Marliave IPEV A. Desautez ENSIETA N. Seube
I. Probst
ESTONIA UT- J. Jaagus
SWEDEN SMHI R. Döscher
H. E. M. Meier K. Wyser
K. Borenäs J. Söderkvist
N. Gustafsson S. Gollvik
V. Perov L. Axell
L. Funkquist SU- M. Tjernström UGOT L.
Anderson G. BJörk

External partners Cooperation EU-US SEARCH for
DAMOCLES LDEO P. Schlosser IARC J. Walsh UAF
H.Eicken WHOI - A.Proshutinsky J. Toole APL
C. Lee J.Morison CRREL - J.Richter-Menge
D.Perovich JAMSTEC T. Kikuchi (J. CAD) IOS H.
Melling (IPS)
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The General Objective of DAMOCLES Observe,
Understand and Model the role of the Arctic
Climate system in the disappearance of the Arctic
perennial Sea-Ice. Predict the
regional-to-global Impacts of that extreme
climatic event on the atmospheric climate
variability (AO/NAO), the hydrological cycle,
Marine Ecosystems and biodiversity, the Global
oceanic MOC, Occurrence of extreme weather events
(storms tracks, polar lows), Impacts on
Indigenous people and the European Community,
northern sea routes and marine transportation,
large scale industrialisation versus resilience
and sustainability and to assess socio-economic
consequences for Europe.
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The specific Objectives of DAMOCLES Determine
the processes responsible for present variability
and changes in the Arctic Climate system Improve
our capabilities to Predict Arctic Climate
changes in particular extreme climate
events Design optimal components of a long-term
integrated monitoring and forecasting system for
the Arctic Ocean. Assess Impacts of an extreme
climate event such as disappearance of the Arctic
perennial Sea-Ice
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DAMOCLES
Developping Arctic Modelling and Observing
Capabilities for Long-term Environmental Studies
PLUTO GRACE GOOS GCOS GMES GEO AOMIP
INTERNATIONAL
COOPERATION CLIC
SEARCH ISAC NABOS CEON ORION
SWARM CARE - IPY GLIMPSE HIRLAM ICEMON
RAPID SITHOS EUROPEAN AND NATIONAL
PROJECTS GREENICE IOMASA
OSISAF(EUMETSAT) ASOF EUROCLIM PROCLIM
CARBOCEAN
WP2 Atmosphere
WP1 Sea-Ice
WP3 Ocean
WP4 Data assimilation large scale modelling and
forecasting
WP8 High Tech. Instrumentation logistics
WP6 Data Base Data Management Access -
Dissemination
WP7 Public Outreach Training
Education End-Users
WP5 Impacts and assessments
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ADCP
Lance
Lance
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MET
TARA
IMB
ADCP
ITAC ADCP
CP
ITAC ADCP
ADCP
CTD POPS
CTD MOPS
CTD
CTD
Ensemble instrumental du Projet Intégré Européen
Damocles
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Sea-ice drift isochrones deduced from the
International Arctic Buoy Program. The red stars
represent the locations of the 20 Ice Tethered
Platforms that would be deployed for the 4-year
AOOS pilot program during the IPY in 2007.
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5
4
6
3
TARA
Beaufort Gyre
2
1
Transpolar Drift
0
Fram Strait
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7 AITP (Fedorov)
3 ITP (Polarstern) 5 ITP (Fedorov)
6 POPS
Tara
0
Fram Strait
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TARA
Positions Argos (au 27/09/06) des bouées météo
dérivant actuellement sur la banquise. La bouée
25576 a été posée à coté de Tara. ( programme
international IABP)
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FRAM 1894
SEDOV 1938-1940
TARA 2006-2008
Russie
Canada
Groenland
Les navires prédécesseurs dérivant en Arctique
le FRAM de FridtjoF Nansen ( 1894-1896) et le
SEDOV (1938-1940)
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Akademik Fedorov
NP35 2007
NABOS/DAMOCLES Sept 2006
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Le travail de DAMOCLES sur le terrain
Déploiement dun POP ( flotteur profilant) sous
la banquise de la Mer de Laptev à partir du
brise-glace Dranitsyn
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Satellite Altimeter scatterometer GPS
Sea ice freeboard
GPS SLP SAT

AITP
ITP
MOPS
sea ice
hydrophone LF2
Sea-ice Temperature
modem HF
Sea ice draft
hydrophone LF2
modem HF
CTD
modem HF
IPS
ADCP
CTD
hydrophone LF1
Transducer SOFAR LF1
glider
Vertical Profiler
float
hydrophone LF1
POPS
Halocline layer
Transducer SOFAR LF2
Atlantic layer
sea bottom
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Joint Russian-German research project (AARI-AWI)
on the North Pole drifting station NP35 during
September 2007-March 2008 EU Project DAMOCLES,
Gascard et al. ? TARA ship crossing the
ArcticOcean
??????? ??-33 (04.08.04)
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MET MAST 10m
SONIC ANEMOMETER 3 m
SONIC ANEMOMETER 3 m
He
ICE MASS BALANCE
TILTMETER
SW LW RADIOMETERS
Kerosene
ICEX
CTD
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POPS Polar Ocean Profiling System
DAMOCLES

• CTD profiling system
• Features
• ARGO CTD sensor (Seabird SBE 41CP)
• profiling from 10 to 1000 meters depth
• data transmission by inductive modem on cable
• data transmission and control through Iridium
  modem ( Short Burst Data SBD transmission)
• capability of one profile per day/year
• Parking depth 300m

- 10 m
bumper
float
CTD
Rider
Profiling float
bumper
- 1000 m
Release
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MOPS Moored Ocean Profiling System
DAMOCLES

• CTD and ADCP profiling system
• Features
• ARGO CTD sensor (Seabird SBE 41 CP)
• profiling vertically from 50 to 1000 meters along
  bottom mooring
• capability daily profile during one year
• Internal data logger
• fitted with acoustic release mechanism
• Equipped with an high speed acoustic modem in the
  future

ADCP
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AITP Acoustic Ice Tethered Platform
DAMOCLES
Antenna Iridium / GPS

• Link between sub-surface underwater vehicles and
  satellite transmission
• SOFAR sound source 780 Hz
• acoustic transmissions 4 times a day telemetry
  encoded lat and longitudes.
• Total transmissions 12 per day
• RAFOS receiver 1560 Hz (1 signal/day).
• Acoustic modems for short range navigation (10kms
  to 10 miles) incl. homing capability and high
  speed communication (100kbits/s) between Gliders,
  Floats and AITPs.
• satellite communication via Iridium and GPS
  positionning.

Electrical-mechanical cable ( 100 m)
Modem
chassis
RAFOS SOFAR
Hydrophone array
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IPS Floats
DAMOCLES

• based on MSI Provor float
• Ice Profiling System (ASL)
• SOFAR RAFOS capabilities (Seascan ) for long
  range loc.
• acoustic modem (Aquatec) for short range
  communication
• IRIDIUM/GPS for satellite communications when
  surfacing

ULS
antenna

• Main features
• drifting depth 50 meters (average)
• ULS accuracy target 5 cm (1 echo/sec.)
• autonomy 1 to 2 years
• RAFOS receiver (780 Hz)
• SOFAR transmitter (1560 Hz) 1 time per day
• high speed (100kbits/s) short range (10km)
  acoustic modem providing short range (10 miles)
  homing navigation for Gliders.
• Other key parameters SLP, Sound speed

Main body electronic, battery control diving
engine
780 Hz hydrophone
Oil ballast
1560Hz resonator
Modem transducer
diameter 20 cm, h 250 cm, 60 Kg
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ENSIETA Glider
DAMOCLES

• Length 2.50m
•  wet  nose (50 cm)
• and tail (80 cm)
•  dry  body 1.2 m
• Albacore profile
• Wingspan 2m
• GOAL 6 m forward per
• meter down/upward at 20 cm/s

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Technological Challenges 1) Developing
Lagrangian and Eulerian in situ observations with
Autonomous, Remote and Attended platforms 2)
Enhancing remote sensing and ground truth
validation for airborne and satellite sensors 3)
Shortening time for accessing data, developing
advanced data assimilation and numerical
modelling techniques 4) Accessing appropriate
logistics and infrastructure
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We need to operate new systems over large domain
and for long-term applications involving high
data rate transmission in near real time of key
climate variables We need to develop 1/
Autonomous platforms (ITPs, IBOs, POPs, MOPs,
AITPs etc) 2/ Underwater acoustics LF, HF for
long and short ranges communication and
navigation (SOFAR/RAFOS technics, Acoustic
modems) Acoustic Thermometry and Acoustic
Tomography Ice Profiling Sonar (ULS) and ADCP 3/
Autonomous Underwater Vehicles (AUVs and
Gliders) 4/ Remote sensing (airborne and
satellites) and ground truth obs.
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Science Support Action SSA SEARCH for
DAMOCLES a joint EU-US initiative for the
development of Arctic Ocean Long-term observing
and forecasting systems, infrastructure and data
management Explore opportunities and
potential benefits (1) to co-ordinate two large
research programmes, SEARCH in the US and
DAMOCLES in the EU (2) to organise workshops
and international conferences.
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SEARCH 7 key scientific questions distributed
over 3 groups of Priority Activities Observing,
Understanding and Responding 1/ Is the Arctic
system moving to a new state ? 2/ To what extent
is the Arctic system predictable ? 3/ To what
extent can recent and ongoing climate changes in
the Arctic be attributed to anthropogenic
forcing, rather than natural modes of variability
? 4/ What is the direction and relative
importance of system feedbacks ? 5/ How are
terrestrial and marine ecosystems affected by
environmental change and its interaction with
human activities ? 6/ How do cultural and socio
economic systems interact with Arctic
environmental changes ? 7/ What are the most
consequential links between the Arctic and the
Earth systems ? SEARCH two overarching groups of
activities a/ Data management b/ Education and
outreach
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. SEARCH 7 key scientific questions are also
questions specifically addressed in DAMOCLES
Work Package 5 A/ DAMOCLES three overarching
groups of activities weather, climate
predictions and model-data reanalysis Overarching
activity 1 Improvement of Numerical Weather,
Ocean and Sea-Ice prediction, short to medium
range prediction assessments (days to
weeks) Overarching activity 2 Interaction
between observations and models and its
optimisation on Climate time scales including the
design of a legacy phase. Overarching activity 3
Production of 4 dimensional gridded analysis and
reanalysis fields. B/ DAMOCLES four Impacts and
Assessments groups of activities Climate
prediction and Impacts on CO2 cycle and
phytoplankton production, Marine Ecosystems and
Human Activities Impact activity 1 Long-term
projections into the 21st century with the help
of improved coupled climate models. Impact
activity 2 CO2 cycle and phytoplankton
production Impact activity 3 Climatic impact on
Marine Ecosystems Impact activity 4 Changing
conditions in the Arctic Ocean a study of the
Impact on Human activities and an assessment of
their adaptation and vulnerability to such
changes. C/ Data Management (Overarching
activity a/ for SEARCH) and Education and
Outreach (Overarching activity b/ for SEARCH)
corresponding to DAMOCLES WP6 and WP7
respectively
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Motivation of ISAC

• The Arctic has been characterized in recent
  decades by a complex of interrelated, pan-arctic
  changes occurring across terrestrial, oceanic,
  atmospheric and human systems
• Observed physical changes have large impacts on
  arctic ecosystems and society
• Anthropogenic Global Change part of signal.
• Arctic Change has global implications
• Climate change signals with largest amplitudes in
  the Arctic (system-scale)

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Science Opportunity/Challenge

• Transition into Greenhouse world is historic
  moment
• Arctic community can deliver significant
  contributions to one of the dominant scientific
  problems and societal challenges (historic
  challenge)
• Positioning of Arctic community at center of
  global change (historic transformation)
• System-scale approach required to study,
  understand and respond to Arctic Change
• International effort required
• Long-term study necessary
• Program of unprecedented scale and complexity
  required
• Arctic community is in position to take on the
  challenge

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