Th-234 sorption and export models in the water column : a review
Benitez-Nelson, Claudia R.
Burd, Adrian B.
Cochran, J. Kirk
Charette, Matthew A.
Buesseler, Ken O.
Jackson, George A.
MetadataShow full item record
Over the past few decades, the radioisotope pair of 238U/234Th has been widely and increasingly used to describe particle dynamics and particle export fluxes in a variety of aquatic systems. The present paper is one of five review articles dedicated to 234Th. It is focused on the models associated with 234Th whereas the companion papers (same issue) are focused on present and future methodologies and techniques (Rutgers van der Loeff et al.), C/234Th ratios (Buesseler et al.), 234Th speciation (Santschi et al.) and present and future applications of 234Th (Waples et al.). In this paper, we review current 234Th scavenging models and discuss the relative importance of the non steady state and physical terms associated with the most commonly used model to estimate 234Th flux. Based on this discussion we recommend that for future work the use of models should be accompanied by a discussion of the effect that model and data uncertainty have on the model results. We also suggest that future field work incorporate repeat occupations of sample sites on time scales of 1-4 weeks in order to evaluate steady state versus non steady state estimates of 234Th export, especially during high flux events (> ca. 800 dpm m-2 d-1). Finally, knowledge of the physical oceanography of the study area is essential, particularly in ocean margins and in areas of established upwelling (e.g. Equatorial Pacific). These suggestions will greatly enhance the application of 234Th as a tracer of particle dynamics and flux in more complicated regimes.
Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Chemistry 100 (2006): 234-249, doi:10.1016/j.marchem.2005.10.014.
Showing items related by title, author, creator and subject.
Impact of circulation on export production, dissolved organic matter, and dissolved oxygen in the ocean : results from Phase II of the Ocean Carbon-cycle Model Intercomparison Project (OCMIP-2) Najjar, Raymond G.; Jin, X.; Louanchi, F.; Aumont, Olivier; Caldeira, Ken; Doney, Scott C.; Dutay, J.-C.; Follows, Michael J.; Gruber, Nicolas; Joos, Fortunat; Lindsay, Keith; Maier-Reimer, Ernst; Matear, Richard J.; Matsumoto, K.; Monfray, Patrick; Mouchet, Anne; Orr, James C.; Plattner, Gian-Kasper; Sarmiento, Jorge L.; Schlitzer, Reiner; Slater, Richard D.; Weirig, Marie-France; Yamanaka, Yasuhiro; Yool, Andrew (American Geophysical Union, 2007-08-08)Results are presented of export production, dissolved organic matter (DOM) and dissolved oxygen simulated by 12 global ocean models participating in the second phase of the Ocean Carbon-cycle Model Intercomparison Project. ...
Siegel, David A.; Buesseler, Ken O.; Doney, Scott C.; Sailley, Sevrine F.; Behrenfeld, Michael J.; Boyd, Philip W. (John Wiley & Sons, 2014-03-10)The export of organic carbon from the surface ocean by sinking particles is an important, yet highly uncertain, component of the global carbon cycle. Here we introduce a mechanistic assessment of the global ocean carbon ...
Climate-induced interannual variability of marine primary and export production in three global coupled climate carbon cycle models Schneider, B.; Bopp, Laurent; Gehlen, M.; Segschneider, J.; Frolicher, T. L.; Cadule, P.; Friedlingstein, Pierre; Doney, Scott C.; Behrenfeld, Michael J.; Joos, Fortunat (Copernicus Publications on behalf of the European Geosciences Union, 2008-04-23)Fully coupled climate carbon cycle models are sophisticated tools that are used to predict future climate change and its impact on the land and ocean carbon cycles. These models should be able to adequately represent natural ...