AOS Faculty Profile
Professor, Ph.D. Columbia University
Address: M48 Guyot Hall
Phone: (609) 258-2936
Email: bender at princeton.edu
Research Involves Studies of Biogeochemistry and Paleoclimate
Much of our work involves measuring the changing concentration and isotopic composition of O2 in air on various timescales, and using the results to characterize the fertility of ecosystems and to study Earth's climate history.
We measure the O2 concentration of air in samples collected for us biweekly at remote sites between Antarctica and Alaska. Rapid mixing in the atmosphere allows us to use O2 concentration changes as measures of rates of net production (photosynthesis minus respiration) on the scale of a hemisphere. Seasonal variations in the O2 concentration primarily reflect the productivity of the ocean biosphere. The change in the O2 concentration from one year to the next reflects the fate of fossil fuel CO2 which does not remain in the atmosphere: how much dissolves in the oceans, how much is incorporated into land plants? O2 is relevant because it is produced when plants grow, but not when CO2 dissolves in seawater.
Changes in the isotopic composition of O2 in air are global. We can use the isotopic composition of O2 to correlate ice cores from different areas, placing their climate records on a common timescale. The results provide information about the sequence of climate changes when Earth warms or cools. Sequence in turn informs us about cause. One result of this work has been to show that increasing concentrations of CO2 in air warm the Earth as ice ages end.
Many aspects of our work involve the interpretation of data using simple or complex mathematical models of atmospheric circulation, climate, and large-scale biological processes.
Some Recent Publications:
Huang, Kuan, Nicolas Cassar, Rik Wanninhkof, and Michael Bender (2013) An isotope dilution method for high-frequency measurements of dissolved inorganic carbon concentration in the surface ocean, Limnology and Oceanography: Methods, 11, 572-583. Doi: 10.4319/lom.2013.11.572.
Rubino, M., D. M. Etheridge, C. M. Trudinger, C. E. Allison, M. O. Battle, R. L. Langenfelds, L. P. Steele, M. Curran, M. Bender, J. W. C. White, T. M. Jenk, T. Blunier, and R. J. Francey (2013) A revised 1000 year atmospheric d13C-CO2 record from Law Dome and South Pole, Antarctica, Journal of Geophysical Research-Atmospheres, 118, 8482-8400, doi:10.10002/jgrd.50668.
Jonssen, B., S. Doney, J. Dunne, and M. Bender (2013) Evaluation of Southern Ocean O2/Ar –based measurements of net community production in a model framework, Journal of Geophysical Research: Biogeosciences, 118, doi: 10.1002/jgrg.20032.
Blunier, T., M. L. Bender, B. Barnett, and J. C. Von Fisher (2012) Planetary fertility during the past 400 ka based on the triple isotope composition of O2 in trapped gases from the Vostok ice core, Climate of the Past, 8, 1509-1526, doi:10.5194/cp-8-1509-2012.
Huang, K. H. Ducklow, M. Vernet, N. Cassar, and M. Bender (2012) Export production and its regulating factors in the West Antarctica Peninsula region of the Southern Ocean, Global Biogeochemical Cycles, 26, doi: 10.1029/2010GB004028.
Hamme, R. C., N. Cassar, V. P. Lance, R. D. Vaillancourt, M. L. Bender, P. G. Strutton, T. S. Moore, M. D. DeGrandpre, C. L. Sabine, D. T. Ho, and B. R. Hargreaves (2012) Dissolved O2/Ar and other methods reveal rapid changes in productivity during a Lagrangian experiment in the Southern Ocean, Deep-Sea Research, 117, doi: 10.1029/2011JC007046.