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Dynamics of the Earth System and the Ice-Core Record (DESIRE). Project submitted to the joint QUEST-INSU AO. 650 kyr of clues from EPICA and Vostok!. Siegenthaler et al., 2005; Spahni et al., 2005; Petit et al., 1999.

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Dynamics of the earth system and the ice core record desire

Dynamics of the Earth System and the Ice-Core Record (DESIRE)

Project submitted to the joint QUEST-INSU AO

650 kyr of clues from epica and vostok
650 kyr of clues from EPICA and Vostok! (DESIRE)

Siegenthaler et al., 2005; Spahni et al., 2005; Petit et al., 1999

The correlative approach can only take us so far, and a mechanistic, model-based approach is now needed

The success of approaches using correlations with Antarctic proxies alone implies the dominance of Southern Ocean mechanisms?

Mudelsee (based only on Vostok data):

pCO2 = 922 + 1.646 * δDt-2000

State of the art ch 4
State of the art: CH mechanistic, model-based approach is now needed4

  • G-IG jumps, 350-700 ppbv

  • Very fast changes (200 ppbv) at DO scales

  • Various sources (terrestrial except marine hydrates) could be involved

    • Distinguishable through isotopes

  • Changing sinks also implicated

    • Little constraint on source/sink balance

QUEST-Deglaciation will look at G-IG change, but in DESIRE we will have the advantage of:

  • new coupled models that cover the CH4 domain

  • different G-IG transitions with different climate changes

  • millennial events encompassing much of the G-IG range

State of the art co 2
State of the art: CO we will have the advantage of: 2

  • G-IG ramps, ~180-280 ppmv in last 450 kyr

  • Lower CO2 in early IG (450-800 kyr)

  • Very close link to Antarctic temperature

    • implies concentration on S. Ocean

  • Physical and biogeochemical processes

    • Data and models provide some constraints

    • But error bars remain very large

Quaternary QUEST is also working on the CO we will have the advantage of: 2 issue, focussed on 1 climate cycle, but we will use the constraints of multiple cycles:

  • In “weak” interglacials, did each mechanism scale with temperature, or were some inactive?

  • Is the phasing at each termination and inception of diagnostic significance?

Dynamics of the earth system and the ice core record desire1
Dynamics of the Earth System and the Ice-core Record (DESIRE)

  • Response to the NERC-INSU joint UK-Fra call “to develop a quantitative and predictive understanding of the ice-core record of changing atmospheric composition”

  • Note that this is a huge question, and we have to balance ambition with reality

  • 0.8 Myrs, CO2 and CH4

  • 3 years, starting in ??? 07

Underlying principles
Underlying principles (DESIRE)

  • Use the new data

  • Use the best modelling tools, people and datasets available to UK and French researchers

  • Use models of appropriate complexity for each question being addressed

  • Tackle achievable aspects of the overall “understanding everything” call

  • WPs arranged around hypotheses relating to (a) CH4 change, (b) CO2 change, (c) the links between these changes and climate change in the coupled system

Strategy (DESIRE)




Propose future


Develop/test some

new modelling



of appropriate


Assess contribution

of different mechanisms

to GHG change

over 800 kyr


new diagnostic


Data constraints

Current partners

Expertise (DESIRE)

Current partners

  • Palaeodata - ice (Jerôme Chappellaz, Eric Wolff and others)

  • Palaeodata - land (Sandy Harrison, Maria Sanchez-Goni)

  • Palaeodata – oceans (Frank Bassinot, Harry Elderfield, Elisabeth Michel, Steve Barker)

  • Ocean dynamics (David Marshall and others)

  • Atmospheric chemistry (Oliver Wild, Dudley Shallcross)

  • Ocean biogeochemistry (Corinne Le Quéré, Laurent Bopp)

  • C cycle modelling (Pierre Friedlingstein, Peter Cox)

  • Ocean modelling (Neil Edwards)

  • Coupled climate models (Pascale Braconnot, Paul Valdes, Gilles Ramstein)

  • EMICs (Neil Edwards, Andy Ridgwell)

  • BAS (Eric Wolff)

  • IPSL/LSCE (Pierre Friedlingstein, Pascale Braconnot, Gilles Ramstein, Laurent Bopp, Frank Bassinot and others)

  • Bristol (Sandy Harrison, Paul Valdes, Andy Ridgwell)

  • LGGE (Jerôme Chappellaz and several others)

  • OU (Neil Edwards)

  • Reading (David Marshall)

  • UEA (Corinne Le Quéré )

  • Cambridge (Harry Elderfield)

  • Exeter (Peter Cox)

  • Plus some unfunded partners (Steve Barker, Maria Sanchez-Goni, Oliver Wild,….)

Strand 1 ch 4 and atmos chem
Strand 1: CH (DESIRE)4 and atmos chem

1.1 Fire modules and integration of methane-related components into IPSL-ESM

1.2 13C into FAMOUS

1.3 Prospects for constraints on source and sink for methane (atmos chem)

1.4 Wetlands/veg data synthesis at MIS 13/15; DO8 and DO 19/20 synthesis by collaboration with QQ

Strand 2 co 2 and c cycle
Strand 2: CO (DESIRE)2 and C cycle

2.1 13CO2 in ice

2.2 Marine sediment constraints on C cycle (including CaCO3 and dissolution in sediments, Chatham Rise, and MIS16/15 and 12/11)

2.3 SO physics and biogeochemistry (effect of eddies, winds and overturning)

2.4 Dust parameterisation (shape, composition)

2.5 MGV development

Strands 3 models and zoos 4
Strands 3 (models and zoos) & 4 (DESIRE)

3.1 Time slices MH, EH, LGM (Q-ESM and IPSL-ESM)

3.2 Other interglacials as time slices (FAMOUS/IPSL-ESM)

3.3 Short transients DO8 and DO19/20 (FAMOUS, IPSL-ESM, MGV)

3.4 Data/model: Compile zoo of ig and g (includes workshops about proxies)

3.5 Transient simulations of transitions and igs (GENIE, MGV) to explore parameters leading to zoo

4 Coordination

Resources (DESIRE)

  • 23 years of new PDRA time

  • Redirected efforts of numerous French researchers and research time of UK Co-Is

  • Bilateral visits and exchanges in most areas

  • Workshops for major data synthesis and proxy interpretation efforts

Management (DESIRE)

  • Wolff and Friedlingstein responsible to QUEST, NERC and INSU

  • Co-Is responsible for each WP

  • Management board providing direction, dealing with problems, organising synthesis

  • Project coordinator assists PI, communications, workshops

  • Project meetings: 2 per year, plus management board interim meetings and virtual meetings

  • Year 3 project meeting will have goal of outlining synthesis paper

International linkages
International linkages (DESIRE)

  • Most participants are already strongly linked to external collaborators (through e.g. EPICA, PMIP, etc.)

  • PIs/Co-Is are strongly involved in all the major international projects (AIMES, PAGES, IGAC, ILEAPS, GCP, …..

  • Potential fast-track initiative (PAGES/AIMES) around EPICA challenge has recently been discussed; DESIRE could make natural leaders for this

A testbed for understanding of the earth system
A testbed for understanding of the Earth System (DESIRE)

DESIRE should be a significant step towards understanding the Earth’s behaviour in response to external (or artificial) forcing

Key deliverables
Key deliverables (DESIRE)

  • Improvements in modelling tools available to UK/Fra researchers

  • New constraining datasets (e.g. 13C), and recommendations for future data needs

  • Improved understanding of some key processes

  • Flagship simulations of critical time periods

  • Synthesis assessment (with uncertainties) of contribution of different mechanisms to the observed records of CO2 and CH4

  • Enduring partnership of top UK and French researchers


Hypotheses (DESIRE)

  • CH4 changes (g-ig, DO, ig-ig) can only be explained by a combination of chnages in both source and sink

    • Constrain solutions that fit all the data; suggest new tests

  • CO2 and insolation are enough to explain the ig-ig and g-g variability observed

    • Effectively test climate sensitivity using warm periods only

  • CO2 changes result from a combination of (mainly SO) mechanisms

    • Improve the mechanisms in models and narrow the error bars for the effect of each