Todd Sowers 
EESI Associate
Todd Sowers
Ph.D., Oceanography, University of Rhode Island, 1991
Department of Geosciences
237 Deike Building
University Park, PA 16802
Phone: (814) 863-8093
email: tas11@psu.edu
Dept. website: http://www.geosc.psu.edu/~sowers/
Current Research Interests:
Global biogeochemical cycles involving trace gas species.
Specifically interested in the relation between climate and greenhouse gas emissions over the last millennia as well as glacial/interglacial timescales.
Microbiology of biota living in ice sheets
Current Research Group
Selected Publications:
Sowers, T., Atmospheric methane isotope records covering the Holocene period, Quaternary Science Reviews 29 213-221, 2010
Mischler, J.A., T.A. Sowers, R.B. Alley, M. Battle, J.R. McConnell, L. Mitchell, T. Popp, E. Sofen, and M.K. Spencer, Carbon and hydrogen isotopic composition of methane over the last 1000 years, Global Biogeochemical Cycles 23 (GB4024), doi: 10.1029/2009GB003460, 2009.
Miteva, V., C. Teacher, T. Sowers, and J. Brenchley, Compairson of the microbial diversity at different depths of the GISP2 Greenland ice core in relationship to deposition climates, Environmental Microbiology 11(3): 640-659, 2009.
Miteva, V., T. Sowers, and J. Brenchley, Production of N20 by ammonia oxidizing bacteria at subfreezing temperatures as a model for assessing the N20 anomalies in the vostok ice core, Geomicrobiology Journal 24(5): 451-459, 2007.
Sowers, T., Late quaternary atmospheric CH4 isotope record suggests marine clathrates are stable, Science 311 (5762): 838-840, 2006.
Sowers, T., S. Bernard, O. Aballain, J. Chappellaz, J.M. Barnola, and T. Marik, Records of the delta C-13 of atmospheric CH4 over the last 2 centuries as recorded in Antarctic snow and ice, Global Biogeochemical Cycles 19(2): Art No. GB2002, 2005.
Price, P.B., and T. Sowers, Temperature dependence of metabolic rates for microbial growth, maintenance, and survival, Proceedings of the National Academy of Sciences of the United States of America, 101(13): 4631-4636, 2004.
Sowers, T. A., R. Alley, and J. Jubenville, Elemental and isotopic records of atmospheric nitrous oxide covering the last 106,000 years from the GISP II and Taylor Dome ice cores, Science,Vol 301, pg 945-948, 2003.
Campen, R.K., T. Sowers, and R.B. Alley, Evidence of Microbial Consortia Metabolizing Within a Low-Latitude Mountain Glacier, Geology, 31 (No. 3), 231-234, 2003.
Sowers, T., A. Rodebaugh, N. Yoshida and S. Toyoda, Extending records of the isotopic composition of atmospheric N 2O back to 1800 A. D. from air trapped in snow at South Pole and the GISP II ice core, Global Biogeochemical Cycles, Vol. 16, NO.4, 1129, doi:10.1029/2002GB001911, 2002.
Sowers, T. A., The N2O record spanning the penultimate deglaciation from the Vostok ice core, Journal of Geophysical Research , Vol 106, D23, pg 31,903-31,914, 2001
Sowers, T.A., and J. Jubenville, A modified extraction technique for liberating occluded gases in ice cores, Journal of Geophysical Research, Vol 105, D23, pg 29,155-29,164, 2000.
Severinghaus, J. P., T. A. Sowers, E. J. Brook, R. B. Alley and M. L. Bender, Timing of abrupt climate change at the end of the Younger Dryas interval from thermally fractionated gases in polar ice, Nature, 391, 141-146, 1998.
Alley, R.B., P.A. Mayewski, T. Sowers, M. Stuiver, K.C. Taylor, and P.U. Clark, Holocene climatic instability: A prominent, widespread event 8200 yr ago, Geology 25(6): 483-486, 1997.
Bender, M., T. Sowers, and E. Brook, Gases in ice cores, Proceedings of the National Academy of Sciences of the United States of America 94(16): 8343-8349, 1997.
Schwander, J., T. Sowers, J.M. Barnola, T. Blunier, A. Fuchs, and B. Malaize, Age scale of the air in the summit ice: Implications for glacial-interglacial temperature change, Journal of Geophysical Research-Atmospheres 102 (D16): 19483-19493, 1997.
Sowers, T., E. Brook, D. Ethridge, T. Blunier, A. Fuchs, M. Leuenberger, J. Chappelaaz, J.M. Barnola, M. Wahlen, B. Deck, and C. Weyhenmeyer, An interlaboratory comparison of techniques for extracting and analyzing trapped gases in ice cores, Journal of Geophysical Research-Oceans 102 (C12): 26527-26538, 1997.
Battle, M., M. Bender, T. Sowers, P.P. Tans, J.H. Butler, J.W. Elkins, J.T. Ellis, T. Conway, N. Zhang, and P. Lang, Atmospheric gas concentrations over the past century measured in air from firn at the South Pole, Nature 383(6597): 231-235, 1996.
Brook, E., T. Sowers and J. Orchardo, Rapid variations in atmospheric methane concentration during the past 110,000 years, Science, 273, 1087-1091, 1996.
Jouzel, J., C. Waelbroeck, B. Malaize, M. Bender, J.R. Petit, M. Stievenard, N.I. Barkov, J.M. Barnola, T. King, V.M. Kotlyakov, V. Lipenkov, C. Lorius, D. Raynaud, C. Ritz, and T. Sowers, Climatic interpretation of the recently extended Vostok ice records, Climate Dynamics 12(8): 513-521, 1996.
Bender, M., T. Sowers, and V. Lipenkov, On the concentrations of O-2, N-2, and AR in trapped gases from ice cores, Journal of Geophysical Research-Atmospheres 100 (D9): 18651-18660, 1995.
Sowers, T. and M. Bender, Climate records covering the last deglaciation, Science 269, 210-214, 1995.
Bender, M.L., T. Sowers, J.M. Barnola, and J. Chappellaz, Changes in the O-2 N2 ratio of the atmosphere during recent decades reflected in the composition of air in the firn at Vostok Station, Antarctica, Geophysical Research Letters 21(3): 189-192, 1994.
Bender, M., T. Sowers, and L. Labeyrie, The dole effect and its variations during the last 130,000 years as measured in the Vostok ice core, Global Biogeochemical Cycles 8(3): 363-376, 1994.
Bender, M., T. Sowers, M.L. Dickson, J. Orchardo, P. Grootes, P.A. Mayewski, and D.A. Meese, Climate correlations between Greenland and Antarctica during the past 100,000 years, Nature 372(6507): 663-666, 1994.
Jeanbaptiste, P, D. Raynaud, F. Mantisi, T. Sowers, and N. Barkov, Measurement of helium-isotopes in Antarctic ice - preliminary results from Vostok, Comptes Rendus De L Academie Des Sciences Serie II 316(4): 491-497, 1993.
Jouzel, J., N.I. Barkov, J.M. Barnola, M. Bender, J. Chappellaz, C. Genthon, V.M. Kotlyakov, V. Lipenkov, C. Lorius, J.R. Petit, D. Raynaud, G. Raisbeck, C. Ritz, and T. Sowers, Extending the Vostok ice-core record of paleoclimate to the penultimate glacial period, Nature 364 (6436): 407-412, 1993.
Sowers, T., M. Bender, L. Labeyrie, D. Martinson, J. Jouzel, D. Raynaud, and Y. S. Korotkevich, 135,000 Year Vostok-SPECMAP Common Temporal Framework, Paleoceanography , 6. 867-875, 1993.
Sower, T., M. Bender, D. Raynaud, and Y.S. Korotkevich, Delta-N-15 of N2 in air trapped in polar ice - a tracer of gas-transport in the firn and a possible constraint on ice age-gas age-differences, Journal of Geophysical Research-Atmospheres 97 (D14): 15683-15697, 1992.
Sowers, T., M. Bender, D. Raynaud, Y. S. Korotkevich, and J. Orchardo, The d 18O of atmospheric O 2 from air inclusions in the Vostok ice core: Timing of CO 2 and ice volume changes during the penultimate deglaciation, Paleoceanography, 6, 679-696, 1991.
Mayewski, P.a., M.S. Twickler, W.B. Lyons, M.J. Spencer, D.A. Meese, A.J. Gow, P. Grootes, T. Sowers, M.S. Watson, and E. Saltzman, The Dominion Range ice core, Queen Maud Mountains, Antarctica - general site and core characteristics with implications, Journal of Glaciology 36 (122): 11-16, 1990.
Bender, M., R. Jahnke, R. Weiss, W. Martin, D. T. Heggie, J. Orchardo, and T. Sowers, Organic-carbon oxidation and benthic nitrogen and silica dynamics in San Clemente Basin, a continental borderland site, Geochimica et Cosmochimica Acta 53(3): 685-697, 1989.
Sowers, T., M. Bender, and D. Raynaud, Elemental and isotopic composition of occluded O-2 and N-2 in polar ice, Journal of Geophysical Research-Atmospheres 94 (D4): 5137-5150, 1989.
Craig, H., Y. Horibe, and T. Sowers, Graviatational seperation of gases and isoptes in polar ice caps, Science 242 (4886): 1675-1678, 1988.
Doering, P.H., J. R. Kelly, C.A. Oviatt, and T. Sowers, Effect of the hard clam mercenaria-mercenaria on benthic fluxes of inorganic nutrients and gases, Marine Biology 94(3): 377-383, 1987.