Faculty

Brad Rosenheim
Assistant Professor

Phone: 504-862-3196
Fax: 504-865-5199
Email: brosenhe@tulane.edu

Department of Earth & Environmental Sciences
Room 210 Blessey Hall
New Orleans, LA 70118

Stable Isotope Laboratory

Education

Ph.D., University of Miami, 2005
B.S., University of Vermont, 1999

Research Interests

Paleoceanography
Geochemistry
Paleoclimatology
Carbon cycle
Carbonate Geochemistry

Select Publications

Rosenheim, B. E., K. M. Roe, B. J. Roberts, A. S. Kolker, M. A. Allison, and K. H. Johannesson (2013), River discharge influences on particulate organic carbon age structure in the Mississippi/Atchafalaya River System, Global Biogeochemical Cycles, 27, doi:10.1002/gbc.20018.     http://onlinelibrary.wiley.com/doi/10.1002/gbc.20018/abstract

Datta S., Neal A. W., Mohajerin T. J., Ocheltree T., Rosenheim B. E., White C. D., and Johannesson K. H. (2011) Perennial ponds are not an important source of water or dissolved organic matter to groundwaters with high arsenic concentrations in West Bengal, India. Geophysical Research Letters 38, L20404, doi:10.1029/2011GL049301     (http://www.agu.org/pubs/crossref/2011/2011GL049301.shtml)

Rosenheim, B.E., M.B. Day, H. Schrum, E.M. Domack, A. Benthien, J.M. Hayes. (2008). "Antarctic sediment chronology by programmed temperature pyrolysis: Methodology and data treatment." Geochemistry, Geophysics, Geosystems.

Rosenheim, B.E., P.K. Swart, A. Eisenhauer.  (2007) “Constraining initial ²³⁰Th activity in incrementally deposited, biogenic aragonite from the Bahamas” Geochimica et Cosmochimica Acta, v.71, pp. 4025-4035.

Rosenheim, B.E., P.K. Swart. (2007) “Caribbean sclerosponge radiocarbon measurements re-interpreted in terms of U/Th age models.” Nuclear Instruments and Measures in Physics Research B. Beam interactions with materials and atoms. v.259(1), pp. 474-478.

Moses, C.S., P.K. Swart, B.E. Rosenheim. (2006); “Evidence of multi-decadal salinity variability in the eastern tropical North Atlantic.” Paleoceanography.

Rosenheim, B. E., P. K. Swart, et al. (2005). "Salinity change in the subtropical Atlantic: Secular increase and teleconnections to the North Atlantic Oscillation." Geophysical Research Letters 32(L02603).

Rosenheim, B. E., P. K. Swart, et al. (2005). "Minor and trace elements in sclerosponge Ceratoporella nicholsoni Biogenic aragonite near the inorganic endmember." Palaeogeography, Palaeoclimatology, Palaeoecology 228: 109-129.

Rosenheim, B. E., P. K. Swart, et al. (2004). "High resolution Sr/Ca records in sclerosponges calibrated to temperature in situ." Geology 32 (2): 145-148.

Swart, P. K., S. R. Thorrold, B.E. Rosenheim, A. Eisenhauer, C.G.A. Harrison, M. Grammer, C. Latcokzy. (2002). "Intra-annual variation in the stable oxygen and carbon and trace element composition of sclerosponges." Paleoceanography 17(3): 1045."

Research Projects

Radiocarbon age spectra in bulk organic material using pyrolysis/combustion techniques. Separation of different components of carbon in bulk organic sedimentary material that may have different sources and histories is useful in both chronological investigations and carbon cycle work. Dr. Rosenheim is refining a technique that leverages differences in thermochemical stability of these different components for separation and subsequent radiocarbon dating. This work is currently being applied to Antarctic sub-ice shelf sediments, Amazon mudbanks off of the coast of French Guiana, and suspended sediment in the Ganges-Brahmaputra system as well as the Mississippi River system.

Circulation history of the subtropical North Atlantic. The subtropics play an important role in climate modulation via an intricate balance of heat transport between shallow subtropical circulation cells and the North Atlantic meridional overturning circulation. In the subtropics, far less is known of the history and variability of heat transport. Dr. Rosenheim has employed geochemical techniques to exploit archives of heat transport in aragonite skeletons of corals and sclerosponges. This multi-proxy approach has yielded salinity records (oxygen isotopes and Sr/Ca ratios), temperature records (Sr/Ca ratios), and mixing records (age-corrected radiocarbon values) of the subtropical N. Atlantic. Current efforts involve a more detailed radiocarbon approach and collaboration with a coupled ocean modeling group at Georgia Tech in Atlanta.

Multiply-substituted isotopologues. Molecules in nature containing bonds between two less abundant stable isotopes carry unique information about formation processes. Mutliply-substituted isotopologues, or clumped isotopes as they are more colloquially called, have been proposed as a robust paleothermometer that is independent of isotope composition of source molecules. To date, published measurements have only been analyzed with 10kV mass spectrometers. In a partnership with Elementar, Dr. Rosenheim will be assessing the feasibility of measuring clumped isotopes using a 3kV Isoprime mass spectrometer. If possible, such an advance would be important to a large community of applied isotope geochemists that has devoted increasing resources to smaller, more affordable mass spectrometers. This investigation will add another potential proxy to the paleo-oceanography work carried out by Dr. Rosenheim’s group at Tulane.

Courses Taught

EENS 2230 – Oceanography
EENS 4240 – Advanced Oceanography
EENS 4250 – Isotopes in the Environment
EENS 6190 – Marine Geology
EENS 6250 – Isotopes in the Environment
EENS – Geochemistry, Sedimentation, and Diagenesis of Carbonates