Prof. Dr. Timothy Shaw 

University of South Carolina, Columbia, USA
Aug 2010 - Jul 2011
Fellow
Sep 1999 - Jul 2000
Fellow

Timothy Shaw

Projects & Publications

Abstract

The global carbon cycle is the ultimate mediator of greenhouse gas induced global warming. Excess atmospheric carbon dioxide (CO2) from fossil fuel burning is the primary cause of warming, but it makes up only a small fraction of CO2 exchange between the earth and atmosphere. The biological portion of the carbon cycle accounts for a much larger fraction of the CO2 exchange so small changes in the processes that mediate CO2 uptake and release are critical to predicting future climate change.

The exchange of biogenic carbon (as dissolved organic matter DOM) between land and the oceans is a critical portion of the cycle. Chemical reactions that occur at the land/sea interface determine whether DOM is sequestered (buried) or remineralized (returned to the atmosphere as CO2). Changes in the amount of DOM that is remineralized to CO2 can alter the reservoir of atmospheric CO2.

This proposal will investigate processes that mediate the remineralization of DOM at the land sea interface. DOM undergoes a range of chemical reactions at the dynamic land sea interface. The beachfront environment is one where the rapid mixing of terrestrial and marine waters creates a zone of high DOM transformation. One reason for this is the production of a set of “super” oxidants called Reactive Oxygen Species (ROS) that have the potential to “burn up” DOM to transform it to CO2 at this interface. This work is critical to determining the net fate of DOM passing through this critical zone of reactivity.

Cooperation partner
Prof. Dr. Thorsten Dittmar, Carl von Ossietzky Universität Oldenburg
Cooperation partner
Prof. Dr. Hans-Jürgen Brumsack, Carl von Ossietzky Universität Oldenburg
Dr. Michiel Rutgers van der Loeff, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Bremerhaven
Prof. Dr. Thorsten Dittmar, Carl von Ossietzky Universität Oldenburg
Publications
T.J. Shaw, K.L. Smith, C.R. Hexel, Rebekkah Dudgeon, Alana D. Sherman, M. Vernet, R.S. Kaufmann (2011). 234Th-Based Carbon Export around Free-Drifting Icebergs in the Southern Ocean. Deep Sea Research Part II: Topical Studies in Oceanography, 58 (11–12), 1384-1391. https://doi.org/10.1016/j.dsr2.2010.11.019
K.L. Smith, A.D. Sherman, T.J. Shaw, A.E. Murray, M. Vernet, A.O. Cefarelli (2011). Carbon export associated with free-drifting icebergs in the Southern Ocean. Deep Sea Research Part II: Topical Studies in Oceanography, 58 (11–12), 1485-1496. https://doi.org/10.1016/j.dsr2.2010.11.027
Justina M. Burns, Preston S. Craig, Timothy J. Shaw, and John L. Ferry (2011). Combinatorial Parameter Space As an Empirical Tool for Predicting Water Chemistry: Fe(II) Oxidation Across a Watershed. Environmental Science & Technology, 45 (9), 4023-4029. https://doi.org/10.1021/es103631f
Lin, H., Rauschenberg, S., Hexel, C., Shaw, T., & Twining, B. (2010). Free-Drifting Icebergs as Sources of Iron to the Weddell Sea. (2011). Free-drifting icebergs as sources of iron to the Weddell Sea. Deep Sea Research Part II: Topical Studies in Oceanography, 58 (11–12), 1392–1406. https://doi.org/10.1016/j.dsr2.2010.11.020
T.J. Shaw, R. Raiswell, C.R. Hexel, H.P. Vu, W.S. Moore, R. Dudgeon, K.L. Smith (2011). Input, composition, and potential impact of terrigenous material from free-drifting icebergs in the Weddell Sea. Deep Sea Research Part II: Topical Studies in Oceanography, 58 (11–12), 1376-1383. https://doi.org/10.1016/j.dsr2.2010.11.012
Philipp Böning, Tim Shaw, Katharina Pahnke, Hans-Jürgen Brumsack (2015). Nickel as indicator of fresh organic matter in upwelling sediments. Geochimica et Cosmochimica Acta, 162, 99-108. https://doi.org/10.1016/j.gca.2015.04.027
W.S. Moore, M. Beck, T. Riedel, M. Rutgers van der Loeff, O. Dellwig, T.J. Shaw, B. Schnetger, H.-J. Brumsack, (2011). Radium-based pore water fluxes of silica, alkalinity, manganese, DOC, and uranium: A decade of studies in the German Wadden Sea. Geochimica et Cosmochimica Acta, 75 (21), 6535-6555. https://doi.org/10.1016/j.gca.2011.08.037
Cooperation partner
Prof. Dr. Hans-Jürgen Brumsack, Carl von Ossietzky Universität Oldenburg
Dr. Michiel Rutgers van der Loeff, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Bremerhaven
Prof. Dr. Thorsten Dittmar, Carl von Ossietzky Universität Oldenburg