My main research focus is to understand how human activities influence ecosystems, from small watersheds to the global scale, and to apply that knowledge to provide solutions. Arguably, land use change and rising atmospheric CO2 are the two most important anthropogenic drivers changing ecosystems. These drivers are closely related to the cycling of many elements. A critical process affecting global element cycles is the chemical weathering of the earth's crust and the transport of weathering products through rivers. My research on weathering includes:
My general research interests include nutrient cycling and water quality management with interdisciplinary collaborations from other fields such as forestry, ecology, and geology.
Ph.D., Environmental Science, Duke University (2002)
Thesis title: Chemical weathering of three Piedmont soils in North Carolina
M.S. Chemistry, Seoul National University (1996)
B.S. Chemistry, Seoul National University (1992)
Raymond, P. A, N.H. Oh, 2009. Long term changes of chemical weathering products in rivers heavily impacted from acid mine drainage: Insights on the impacts of coal mining on regional and global carbon and sulfur budgets. Earth and Planetary Science Letters, in press.
Raymond, P.A.*, Oh, N.H.*, Turner, R.E., and Broussard, W. Anthropogenically enhanced fluxes of water and carbon from the Mississippi River. Nature (2008) 451, doi:10.1038/nature06505. *These authors contributed equally to this work.
Oh, N.H., Hofmockel, M., Lavine, M.L., and Richter, D.D. Did elevated atmospheric CO2 alter soil mineral weathering?: An analysis of five-year soil water chemistry data at Duke FACE study. Global Change Biology (2007) 13, 2626-2641.
Butman, D., Raymond, P.A., Oh, N.H., and Mull, K. Quantity, 14C-age, and lability of desorbed soil organic carbon in freshwater and seawater. Organic Geochemistry (2007) 38, 1547-1557.
Raymond, P.A. and Oh, N.H. An empirical study of climatic controls on riverine carbon export from 3 major US watersheds. Global Biogeochemical Cycles (2007) 21, GB2022, doi: 10.1029/2006GB002783.
Richter D.D., Oh, N.H., Fimmen, R., and Jackson, J. The rhizosphere and soil formation. In The Rhizosphere - An Ecological Perspective, Z.G. Cardon and J.L. Whitbeck, editors, Academic Press, San Diego (2007).
Oh, N.H. and Raymond, P.A.. Contribution of agricultural liming to riverine bicarbonate export and CO2 sequestration in the Ohio River basin. Global Biogeochemical Cycles (2006) 20, GB3012, doi: 10.1029/2005GB002565.
Oh, N.H. and Richter, D.D. Elemental translocation and loss from three highly weathered soil-bedrock profiles in the southeastern United States. Geoderma (2005) 126, 5-25.
Oh, N.H., Kim, H.S., and Richter, D.D. What regulates soil CO2 concentrations?: A modeling approach to CO2 diffusion in deep soil profiles. Environmental Engineering Science (2005) 22, 38-45.
Oh, N.H. and Richter, D.D. Soil acidification induced by elevated atmospheric CO2. Global Change Biology (2004) 10, 1936-1946.