All peer-reviewed: * denotes student author; # denotes post-doctoral author; % denotes senior lab member.
We are investigating how the carbon isotope composition of the atmosphere is transmitted to the carbon istotope composition of terrestrial land plants, particularly at high pCO2.
B.A. Schubert% and A.H. Jahren. 2012. The effect of atmospheric CO2 concentration on carbon isotope fractionation in C3 land plants. Geochimica et Cosmochimica Acta, 96: 29-43. (view/download pdf).
D.C. King*, B.A. Schubert% and A.H. Jahren. 2012. Practical considerations for the use of pollen δ13C value as a paleoclimate indicator. Rapid Communications in Mass Spectrometry, (accepted and in-press). (view/download pdf).
B.A. Schubert%, A.H. Jahren. 2011. Quantifying seasonal precipitation using high-resolution carbon isotope analyses in evergreen wood. Geochimica et Cosmochimica Acta, 75(22): 7291-7303. (view/download pdf)
B.A. Schubert% and A.H. Jahren. 2011. Fertilization trajectory of the root crop Raphanus sativus across atmospheric pCO2 estimates of the next 300 years. Agriculture, Ecosystems, and Environment, 140(1-2) 174-181, doi: 10.1016/j.agee.2010.11.024. (view/download pdf)
A.H. Jahren and N.C. Arens. 2009. Prediction of atmospheric δ13CO2 using plant cuticle isolated from fluvial sediment: tests across a gradient in salt content.Palaios, 24, 394-401. doi: 10.2110/palo.2008.p08-069r. (view/download pdf)
A.H. Jahren, N.C. Arens and S.A. Harbeson*. 2008 (Invited). Prediction of atmospheric δ13CO2 using fossil plant tissues. Reviews of Geophysics, 46/2006RG0002. (view/download pdf target="_blank")
N.C. Arens, A.H. Jahren and R. Amundson. 2000. Can C3 plants faithfully record the carbon isotopic composition of atmospheric carbon dioxide? Paleobiology, 26(1), 137-164. (view/download pdf)
Back to top
The Carbon Isotope Composition of Ancient Terrestrial Organic Matter
We are investigating how the carbon isotope composition of fossil land plants and fossil organic matter can be used to infer climate change in ancient ecosystems.
B.A. Schubert% and A.H. Jahren. 2013. Reconciliation of marine and terrestrial carbon isotope excursions based on changing atmospheric CO2 levels. Nature Communications, 4:1653, DOI: 10.1038/ncomms2659. (request pdf reprint).
A.H. Jahren, B.A. Schubert%, L. Marynowski and J.P. Wilson*. The carbon isotope organic geochemistry of Early Ordovician rocks from the Annascaul Formation, County Kerry. Irish Journal of Earth Sciences, 31: 1-12; doi: 10.3318/IJES.2013.31. (view/download pdf).
G.J. Retallack and A.H. Jahren. 2008. Methane release from igneous intrusion of coal during Late Permian extinction events. Journal of Geology, 116, 1-20. (view/download pdf)
G.J. Retallack, T.L. Greaver# and A.H. Jahren. 2007. Return to Coalsack Bluff and the Permian-Triassic boundary in Antarctica. Global and Planetary Change, 55, 90-108. (view/download pdf)
G.J. Retallack, C.A. Metzger*, T.L. Greaver#, A.H. Jahren, R.M.H. Smith and N.D. Sheldon. 2006. Middle-Late Permian mass extinction on land. GSA Bulletin, 118(11), 1398-1411. (view/download pdf)
A.H. Jahren, C.P. Conrad, N.C. Arens, G. Mora# and C. Lithgow-Bertelloni. 2005. A plate tectonic mechanism for methane hydrate release along subduction zones. Earth and Planetary Science Letters, 236, 691-704. (view/download pdf)
G.J. Retallack, A.H. Jahren, N.D. Sheldon*, R. Chakrabarti, C.A. Metzger and R.M.H. Smith. 2005. The Permian-Triassic boundary in Antarctica. Antarctic Science, 17(2), 241-258. (view/download pdf)
A.H. Jahren. 2002. The biogeochemical consequences of the mid-Cretaceous superplume. Journal of Geodynamics, 34, 177-191. (view/download pdf)
N.C. Arens and A.H. Jahren. 2002. Chemostratigraphic correlation of four fossil-bearing sections in southwestern North Dakota. in Hartman, J.H., Johnson, K.R., and Nichols, D.J. eds., The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An integrated record of the end of the Cretaceous: Boulder, Colorado, Geological Society of America Special Paper, 361, 75-93. (view/download pdf)
A.H. Jahren, N.C. Arens, G. Sarmiento, J. Guerrero and R. Amundson. 2001. Terrestrial record of methane hydrate dissociation in the Early Cretaceous. Geology, 29(2), 159-162. (view/download pdf)
N.C. Arens and A.H. Jahren. 2000. Carbon isotopic excursion in atmospheric CO2 at the Cretaceous-Tertiary boundary: Evidence from terrestrial sediments. Palaios, 15(4), 314-322. (view/download pdf)
Back to top
The Arctic Eocene
45 million years ago, Arctic regions contained vast deciduous forests dominated by Metasequoia trees. We are looking at the stable isotope composition of a variety of fossil substrates to reconstruct basic climate parameters as well as to gain insight into the ecology of the organisms living there.
B.A. Schubert%, A.H. Jahren, J.J. Eberle, L.S.L. Sternberg, and D.A. Eberth. 2012. A summertime rainy season in the Arctic forests of the Eocene. Geology, 40(6): 523–526, doi: 10.1130/G32856.1. (view/download pdf).
A.H. Jahren, M.C. Byrne*, H.V. Graham*, R.A. Summons and L.S.L. Sternberg. 2009. The environmental water of the Middle Eocene Arctic: Evidence from δD and δ18O within specific compounds. Palaeogeography, Palaeoclimatology, Palaeoecology, 271(1-2), 96-103. doi: 10.1016/j.palaeo.2008.09.016. (view/download pdf)
A.H. Jahren and L.S.L. Sternberg. 2008. Annual patterns within tree rings of the Arctic middle Eocene (~45 Ma): Isotopic signatures of precipitation, relative humidity and deciduousness. Geology, 36(2), 99-102. (view/download pdf)
A.H. Jahren. 2007 (Invited). The Arctic forest of the middle Eocene. Annual Review of Earth and Planetary Sciences, 35, 509-540. (view/download pdf)
A.H. Jahren and L.S.L. Sternberg. 2003. Humidity estimate for the middle Eocene Arctic rain forest. Geology, 31(5), 463-466. (view/download pdf)
A.H. Jahren and L.S.L. Sternberg. 2002. Eocene meridional weather patterns reflected in the oxygen isotopes of Arctic fossil wood. GSA Today, 12(1), 4-9. (view/download pdf)
Back to top
We are working with colleagues to pursue the isotope biophysiology of water in plants, particularly for the interpretation of cellulose and its derivatives.
L.S.L. Sternberg, M.C. Pinzon, P.F. Vendramini, W.T. Anderson, A.H. Jahren and K. Beuning. 2007. Oxygen isotope ratios of cellulose derived phenylglucosazone: An improved paleoclimate indicator of environmental water and relative humidity. Geochimica et Cosmochimica Acta, 71, 2463-2473. (view/download pdf)
L.S.L. Sternberg, M.C. Pinzon, W.T. Anderson and A.H. Jahren. 2006. Variation in oxygen isotope fractionation during cellulose synthesis: molecular and biosynthetic effects. Plant, Cell and Environment, 29, 1881-1889. (view/download pdf)
G. Mora# and A.H. Jahren. 2003. Isotopic evidence for the role of plant development on transpiration in deciduous forests of the southern United States. Global Biogeochemical Cycles, 17(2), 2002GB001981. (view/download pdf)
Back to top
We have started new work investigating the link between stable isotopes in human blood and in human diet.
R.J. Panetta#, A.H. Jahren. 2011. Single-step transesterification with simultaneous concentration and stable isotope analysis of fatty acid methyl esters by gas chromatography-combustion-isotope ratio mass spectrometry.Rapid Communications in Mass Spectrometry, 25(10) 1372-1381. (view/download pdf)
B.M. Davy, A.H. Jahren, V.E. Hendrick*, D.L. Comber*. 2011. Association of δ13C in fingerstick blood with added-sugar and sugar-sweetened beverage Intake. Journal of the American Dietetic Association, 111(6) 874-878. (view/download pdf)
E.H. Yeung#, C.D. Saudek, A.H. Jahren, W.M.L. Kao, M. Islas*, R. Kraft*, J. Coresh, and C.A. Anderson. 2010. Evaluation of a novel isotope biomarker for dietary consuption of sweets. American Journal of Epidemiology; doi: 10.1093/aje/kwq247. (view/download pdf)
A.H. Jahren, and Schubert, BA#. 2010. The corn content of French-fry oil from national chain vs. small business restaurants, Proceedings of the National Academy of Sciences USA, 107(5) 2099-2101. (view/download pdf)
A.H. Jahren, R.A. Kraft*. 2008. Carbon and nitrogen stable isotopes in fastfood: Signatures of corn and confinement. Proceedings of the NationalAcademy of Sciences, 105(46), 17855-17860. doi: 10.1073 pnas.0809870105. (view/download pdf)
R.A. Kraft*, A.H. Jahren and C.D. Saudek. 2008. Clinical-scale investigation of stable isotopes in human blood: δ13C and δ15N from 406 patients at the Johns Hopkins Medical Institutions. Rapid Communications in Mass Spectrometry, 22(22), 3683-369. (view/download pdf)
A.H. Jahren, C. Saudek, E. Yeung*, W.H. Kao, R. Kraft* and B. Caballero. 2006. An isotopic method for quantifying sweeteners derived from corn and sugar cane. American Journal of Clinical Nutrition, 84, 1380-1384. (view/download pdf)
Back to top
We have researched new ways to gain the oxygen isotope signature from organic substrates containing nitrogen, such as IED explosives.
W.M. Hagopian%, and A.H. Jahren. 2012. Elimination of nitrogen interference during online oxygen isotope analysis of nitrogen-doped organics using the “NiCat” nickel reduction system. Rapid Communications in Mass Spectrometry, 26: 1776-1782 (view/download pdf).
G.B. Hunsinger#, W.M. Hagopian%, A.H. Jahren. 2010. Offline Oxygen Isotope Analysis of Organic Compounds with High N:O, Rapid Communications in Mass Spectrometry, 24, 3182-3186. (view/download pdf)
W.M. Hagopian%, and A.H. Jahren. 2010. Minimization of Sample Requirements for δ18O in Benzoic Acid, Rapid Communications in Mass Spectrometry, v. 24, p. 2542-2546; doi 10.1002/rcm.4669. (view/download pdf)
Back to top