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THOR Deliverable D19
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Deliverable description:
Associated with
milestone (No.)
Analyses of sensitivity experiments on THC adjustment: the response
of the THC to changes in deep water formation and on coupled and
uncoupled modes of variability.
10. THC sensitivity and ocean-ice-atmosphere
feedback studies completed
WP No.
1.1
Lead Beneficiary:
WP Title
Analyses of millennium-scale simulations with coupled
atmosphere-ocean general circulation models
Work duration1)
1)
2)
1-36
2 MPG-M
Delivery deadline2):
2011-11-30
Delivery date: 2011-11-XX
Work duration = project month
Delivery deadline: as contracted in Description of Work (Annex 1 to Grant Contract)
Leader:
Contributing partners:
THOR Deliverables
Please list the names of the scientist(s)
involved
Please list the names of the scientist(s)
involved
Please list the names of the scientist(s)
involved
Please list the names of the scientist(s)
involved
2. MPG-M
3. Met O
4. UPMC-LOCEAN
19. NERSC
Deliverable D19
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Index
1. Executive Summary .......................................................................................................... 3
2. Main objectives, description of work and role of participants (Annex I: DoW) .................... 3
3. Report on Deliverable D19 ................................................................................................ 4
4. List of Publications (cumulative, add the new publications) ............................................... 4
5. The project/delivery is delayed:  Yes  No ................................................................. 5
6. Changes made and difficulties encountered, if any............................................................ 5
7. Efforts for the deliverable D19 ........................................................................................... 5
8. Sustainability ..................................................................................................................... 5
THOR Deliverables
Deliverable D19
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1. Executive Summary
Input requested here.
2. Main objectives, description of work and role of
participants (Annex I: DoW)
Objectives
 To establish the main statistical characteristics of the THC in the control and
Millennium simulations
 To assess the ability of the models to reproduce observed decadal to centennial
variations (CT1, WP1.2)
 To assess the role of the external forcing in shaping the THC
 To assess the dynamics of THC adjustment and decadal water mass changes in
relation to observations (CT3)
 To establish the impact of THC on climate
 To establish the role of the oceanic and atmospheric fresh water budgets and transports
for the THC
 To devise a standard model testing procedure
Description of work and role of participants
Long-term AOGCM experiments, forced “Millennium” [NERSC, UPMC-LOCEAN, MET-O,
MPG-M] and control [ALL PARTNERS] simulations, will provide a data-base for the
analyses of THC characteristics within one model and between the models that can be
compared with observations. Additional sensitivity studies will be performed to better
understand individual processes.
Task 1.1.1 Assessment of the Millennium runs and role of the external forcing
 The signature of THC variability will be diagnosed from the models and properties
that are available from observations (WP 1.2) will be assessed [NERSC, UPMCLOCEAN, MET-O, MPG-M].
 The representation of simulated processes important for THC dynamics and water
mass transformation will be compared with observations (CT3) [MPG-M]. Forced and
unforced simulations will be compared to establish the role of external forcing [MPGM, MET-O].
 A procedure for coordinated model testing will be designed [UPMC-LOCEAN] and
applied to all models [ALL PARTNERS].
Task 1.1.2 THC variability on decadal to centennial timescale
 Mechanisms responsible for decadal to centennial variability will be coherently
analysed in the different models. Process-based assessment of THC dynamics and
decadal water mass transformation will focus on overflows, deep-water formation and
its precondition, and Southern Ocean control [MPG-M, NERSC, MET-O, UPMCLOCEAN].
 The extent to which recent changes in North Atlantic heat and fresh water content are
related to THC changes will be assessed in a suite of 20th Century model simulations
[MET-O]
THOR Deliverables
Deliverable D19
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

Sensitivity experiments will be designed [MPG-M] to study the impact of changes in
the project’s observational regions Labrador Sea and GSR onto the THC [MPG-M,
NERSC, MET-O, UPMC-LOCEAN].
Budget diagnostics and statistical analysis diagnostics for the interpretation of
observed and modelled fields will be designed [MET-O] and applied to all models
[MPG-M, NERSC, MET-O, UPMC-LOCEAN].
Task 1.1.3 Ocean – atmosphere feedbacks and climatic impact of the THC changes
 The evaluation of the relative role of coupled and uncoupled dynamics and remote
atmospheric links will be based on statistical analyses of lead/lag relationship
[NERSC, UPMC-LOCEAN, MET-O, MPG-M ] aided by coupled and uncoupled
sensitivity experiments [MPG-M, NERSC, UPMC-LOCEAN].
 Additional partial coupled experiments will be performed to identify the extent to
which the AMO is part of a coupled climate mode. The role of THC changes for the
European and Arctic climate will be studied [MPG-M, NERSC, UPMC-LOCEAN,
MET-O].
Deliverables



D12 Establish the main statistical signatures of THC variability on decadal to
multidecadal time scales and the role of variability for heat and fresh water transports
(Month 24).
D19 Analyses of sensitivity experiments on THC adjustment: the response of the
THC to changes in deep water formation and on coupled and uncoupled modes of
variability. (Month 36, this is the current deliverable due!)
D33 Synthesis of main dynamics and feedbacks of decadal to centennial variability in
the different coupled models and assessment of the role of the ocean in the variability
seen in the Millennium climate. (Month 48)
3. Report on Deliverable D19
Input requested
References
Input requested
4. List of Publications (cumulative, add the new
publications)
Add the new publications here below.
Peer reviewed articles:
THOR Deliverables
Deliverable D19
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Plan for future publication:
5. The project/delivery is delayed:
 Yes
 No
6. Changes made and difficulties encountered, if any
None.
7. Efforts for the deliverable D19
Institute
Person-Months
Period
7.5
12.2008 – 11.2011
12.2008 – 11.2011
22
12.2008 – 11.2011
4 UPMC-LOCEAN
18
12.2008 – 11.2011
19 NERSC
12
Total estimated effort for this deliverable was 44 person-months, actual amount XXX
including in-kind person-month.
2 MPG-M
3 Met O
8. Sustainability
Provide inputs here.
THOR Deliverables
Deliverable D19