EPOCA Kick-off Meeting June 2008: Nice Theme 1Ocean chemistry and biogeography What is the past and recent variability of ocean carbonate chemistry (including nutrients and trace metals) and geographical distribution of marine organisms? Among other methods, paleo- reconstructions will be used to investigate the response of (mainly) calcifying organisms to past changes in ocean acidification.

Objectives 1.Determine oceanic carbonate chemistry evolution over a range of time scales in systems of natural variability (Glacial to Interglacial, Holocene) and in human perturbed systems (industrial era) 2.Integrate proxy records with present day observations (link to WP3) 3.Improve understanding of proxy incorporation during calcification (link to WP4) WP2Past variability of ocean chemistry (paleo-reconstruction)

Objectives 4.Evaluate the response of calcifying organisms to past changes in ocean acidification 5.Assess the role of carbonate dissolution in the natural carbonate chemistry of the ocean 6.Advance the parameterization of climate and biogeochemical processes affected by ocean acidification in model predictions (link to WP10, WP12)

Determination of the evolution of oceanic carbonate chemistry over a range of time scales in systems of natural variability and in human perturbed systems

Determination of the evolution of oceanic carbonate chemistry over a range of time scales in systems of natural variability and in human perturbed systems Rapid Events Glacial-interglacial changes in ocean carbonate system Records of the industrial age

Work and participants 1.Analyses of foraminifera and coccoliths (geochemistry, isotopes, morphometry) from marine sediment cores for paleo reconstruction Cambridge, Bergen, Amsterdam, CEREGE, AWI, Bern 2.Analyses of foraminifera and coccoliths from core-tops, sediment traps and water column samples for integration of proxy and present day records Cambridge, Bergen, Amsterdam, CEREGE, AWI, Bern 3.Analyses of cold water corals: field calibration and geochemistry LSCE

Work and participants 4.Determination of the dissolution kinetics of biogenic carbonates Brussels 5.Model simulation (including a sediment module) of Glacial to Interglacial rain ratio and carbonate compensation response Bergen, Bern,Bristol 6.Model simulation of Cretaceous/Paleogene acidification event LSCE,Southampton,Bristol

System where atmospheric CO2 defined by ocean-atmosphere interactions with internal and external carbon reservoirs System where atmospheric CO2 change shows response in oceans

“Paleo-analogs”

There are no good analogs for the perturbations we are making. The world has never before seen such a rapid rise in greenhouse gases with the present-day configuration of the continents and with large amounts of polar ice. The simplest use of the paleo record - just going back to a point that had similar conditions to what we expect for the future - doesn't work very well because because there are no good analogs for the perturbations we are making. So more sophisticated approaches must be developed. Exception is Records of the Industrial Age

Records of the industrial age Challenge: Obtain marine records that define seawater carbonate chemistry Investigate whether/to what extent records modified by increase in anthropogenic CO2

Archives Corals Rapidly-accumulating sediment cores Core tops Water column samples (trap, tow) Experimental systems (lab and field)

Tools Foraminifer shell weight Coccolith mass Shell chemistry (  13 C,  11 B, Sr/Ca, B/Ca….) Calibrate/improve with links to other WPs Examples from EPOCA proposal…..

Planktonic foraminifer G. Bulloides normalised shell mass and glacial-interglacial [CO 3 2- ] Barker & Elderfield (2002)

B/Ca-  [CO 3 2- ] in benthic foraminifera and [CO 3 2- ] reconstruction of N. Atlantic glacial water column Yu and Elderfield (2007)

Records of the industrial age from North Atlantic

RAPID core-21-12B southern Gardar Drift 57 o 27.09’N 27 o 54.53’W 2630m water depth Boessenkool et al (2006) Iglesias Rodriguez et al (2008) Elderfield et al unpublished data

Records of the industrial age from North Atlantic Core HM Ormen Lange 63 o 45.8’N 05 o 15.3’E 845.4m water depth Carin Andersson Dahl (Berknes Centre, Bergen) unpublished data

Records of the industrial age from North Atlantic Core HM Ormen Lange 63 o 45.8’N 05 o 15.3’E 845.4m water depth Carin Andersson Dahl (Berknes Centre, Bergen) unpublished data

Ormen Lange cores HM and P1-003MC 210 Pb dating method Sedimentation rate = 1.3 to 2.2 mm a cm intervals ≈ 2.3 to 3.8 years AD Andersson Dahl

Gardar Drift core RAPID-21-12B 210 Pb dating method Linear sedimentation rate = 2.3 ± 0.2 mm a -1 Sampled at 0.5 cm intervals ≈ 2.2 ± 0.2 years AD Boessenkool et al (2006)

No long term trend in coccolithophore species composition Iglesias Rodriguez et al (2008)

40 % increase in average coccolith mass since ca 1950 Iglesias Rodriguez et al (2008)

Shell weight of G.bulloides in µm 12 % decrease in planktonic foraminifera mass since ca 1900

increase in average coccolith mass decrease in planktonic foraminifera mass

decrease in G bulloides Sr/Ca related to calcification rate -  [CO 3 2- ] - inorganic calcite

Lessons from the past Shell weight and Sr/Ca can vary for other reasons

G. Bulloides shell weight and  18 O in Southern Ocean Low shell weight at interglacial (high CO2) times Greaves et al (2008)

Benthic foraminiferal Sr/Ca and  18 O in Southern Ocean

An idea for paleo rain ratio Late Glacial Maximum carbonate saturation in the North Atlantic Ocean and rain ratio

Conclusions 1.Industrial age records a challenge but very important 2.EPOCA must enable integration of modern observational studies with paleo records Combination of 1 and 2 potential to make a very significant contribution to understanding of effects of ocean acidification 3.Records of Glacial-Interglacial periods and rapid events also relevant