Southern Ocean paleoceanography and glacial-interglacial changes in the global efficiency of the biological pump.

The first aspect of the research will concentrate on reconstructing past changes in export production using a multi-proxy approach and deep ocean ventilation using redox-sensitive trace metals over glacial/interglacial cycles on high accumulation, well-dated sedimentary archives recently retrieved from the Indian sector of the Southern Ocean. In particular, we seek to understand the role of the Southern Ocean in past atmospheric CO2 changes, a question of central importance to predicting the future of CO2 and climate in the context of human perturbation.

Relevant publications:

Gottschalk, J., Skinner, L.C., Lippold, J. Vogel, H. Frank, N., Jaccard, S.L., Waelbroeck, C. Biological and physical controls in the Southern Ocean on past millennial-scale atmospheric CO2 changes. Nature Communications 7:11539, 2016.

Jaccard, S.L., Galbraith, E.D., Martínez-García, A., Anderson, R.F. Covariation of deep Southern Ocean oxygenation and atmospheric CO2 through the last ice age. Nature, 530, 207-210, 2016.

Galbraith, E.D., Jaccard, S.L. Deglacial weakening of the oceanic soft tissue pump: global constraints from sedimentary nitrogen isotopes and oxygenation proxies. Quaternary Science Reviews, 109, 38-49, 2015.

Martínez-García, A., Sigman, D.M., Ren, H., Anderson, R.F., Straub, M., Hodell, D.A., Jaccard, S.L., Eglinton, T.I., Haug, G.H., 2014, Iron Fertilization of the Subantarctic Ocean During the Last Ice Age. Science, 43, 1347-1350.

Jaccard, S.L., Hayes, C.T., Martínez-García, A., Hodell, D.A., Anderson, R.F., Sigman, D.M., Haug, G.H. Two Modes of Change in Southern Ocean Productivity Over the Past Million Years. Science, 339, 1419-1423, 2013.

Martínez-García, A., Rosell-Mélé, A., Jaccard, S.L., Geibert, W., Sigman, D.M., Haug, G.H., Southern Ocean dust-climate couplings over the last 4,000,000 years, Nature, 476, 312-316, 2011.