Glacial – Deglacial – Interglacial Ocean Biogeochemistry
The recurring Pleistocene cycles of ice ages and intervening interglacial stages arguably constitute the best-studied period of earth history. It has become clear that these climate variations are closely coupled to changes of atmospheric CO2, ocean circulation, and the ocean’s cycling of carbon and nutrients. And yet, many important aspects of glacial ocean overturning and carbon sequestration via the biological pump still await a comprehensive explanation. In the age of man-made climate change it becomes a high-priority to understand this coupling between climate, biology and geochemistry on a mechanistic level.
A particularly large number of observational datasets exists for the end of the last ice age, the last deglaciation and the current Holocene interglacial epoch, aided by the availability of radiocarbon (14C) dating. This presents the paleoclimate and paleoceanography communities with perhaps the best opportunity to investigate the operation of the climate system. Using numerical techniques I work to refine the understanding of down-core geochemical reconstructions with the goal to improve their interpretation in terms of environmental conditions and global versus regional geochemical implications.
- Galbraith, E.D., Kwon, E.-Y., Bianchi, D., Hain, M.P., and Sarmiento, J.L. (2015) The impact of atmospheric pCO2 on carbon isotope ratios in the atmosphere and ocean, Global Biogeochemical Cycles, doi: 10.1002/2014GB004929 --- Publication Highlight at AGUniverse, 6(10), May 28th, 2015.
- Hain, M.P., Sigman, D.M., and Haug, G.H. (2014) Distinct roles of the Southern Ocean and North Atlantic in the deglacial atmospheric radiocarbon decline, Earth and Planetary Science Letters, 394, 198-208, doi: 10.1016/j.epsl.2014.03.020
- Hain, M.P., Sigman, D.M., and Haug, G.H. (2014) The Biological Pump in the Past, in Treatise on Geochemistry 2nd Edition, 8(18), 485-517, doi:10.1016/B978-0-08-095975-7.00618-5
- Kwon, E.Y., Hain, M.P., Sigman, D.M., Galbraith, E., Sarmiento, J.L., and Toggweiler, J.R. (2012) North Atlantic ventilation of "southern-sourced" deep water in the glacial ocean, Paleoceanography, doi:10.1029/2011PA002211 --- among Paleoceanography “most popular” April and June 2012 --- Research Highlight at Nature Geoscience June, 2012.
- Sigman, D.M., and Hain M.P. (2012) The Biological Productivity of the Ocean, Nature Education.
- Hain, M.P., Sigman, D.M., Haug, G.H. (2011) Shortcomings of the isolated abyssal reservoir model for deglacial radiocarbon changes in the mid-depth Indo-Pacific Ocean, Geophysical Research Letters, 38, L04604, doi:10.1029/2010GL046158 --- Editors' Choice at Science Magazine March 4th, 2011.
- Hain, M.P., Sigman, D.M., Haug, G.H. (2010) Carbon dioxide effects of Antarctic stratification, North Atlantic Intermediate Water formation, and Subantarctic nutrient drawdown during the last ice age: Diagnosis and synthesis in a geochemical box model, Global Biogeochemical Cycles, 24, GB4023, doi:10.1029/2010GB003790 --- among GBC “most popular” Dec. 2010
- Sigman, D.M., Hain, M.P., Haug, G.H. (2010) The polar ocean and glacial cycles in atmospheric CO2 concentration, Nature, 466, 47-55, doi:10.1038/nature09149