Index Catalog // ScholarsArchive@OSU

Creator:: Thibodeau, Benoit, Not, Christelle, Hu, Jiang, Schmittner, Andreas, Noone, David, Tabor, Clay, Zhang, Jiaxu, and Liu, Zhengyu
Abstract:: The Atlantic meridional overturning circulation (AMOC) is a key component of the global climate system. Recent studies suggested a twentieth-century weakening of the AMOC of unprecedented amplitude (similar to 15%) over the last millennium. Here we present a record of O-18 in benthic foraminifera from sediment cores retrieved from the...
Resource Type:: Article

Creator:: Schmittner, Andreas, Tonkonojenkov, Roman, Urban, Nathan M., Goes, Marlos, Haran, Murali, and Keller, Klaus
Abstract:: Current projections of the oceanic response to anthropogenic climate forcings are uncertain. Two key sources of these uncertainties are (1) structural errors in current Earth system models and (2) imperfect knowledge of model parameters. Ocean tracer observations have the potential to reduce these uncertainties. Previous studies typically consider each tracer...
Resource Type:: Article

Creator:: Zhang, Xiao, Prange, Matthias, Steph, Silke, Butzin, Martin, Krebs, Uta, Lunt, Daniel J., Nisancioglu, Kerim H., Park, Wonsun, Schmittner, Andreas, Schneider, Birgit, and Schulz, Michael
Abstract:: The early Pliocene warm phase was characterized by high sea surface temperatures and a deep thermocline in the eastern equatorial Pacific. A new hypothesis suggests that the progressive closure of the Panamanian seaway contributed substantially to the termination of this zonally symmetric state in the equatorial Pacific. According to this...
Resource Type:: Article

Creator:: Ahn, Jinho, Brook, Edward J., Schmittner, Andreas, and Kreutz, Karl
Abstract:: During the last glacial period atmospheric carbon dioxide and temperature in Antarctica varied in a similar fashion on millennial time scales, but previous work indicates that these changes were gradual. In a detailed analysis of one event we now find that approximately half of the CO₂ increase that occurred during...
Resource Type:: Article

Creator:: Zickfeld, Kirsten, Eby, Michael, Matthews, H. Damon, Schmittner, Andreas, and Weaver, Andrew J.
Abstract:: Coupled climate–carbon models have shown the potential for large feedbacks between climate change, atmospheric CO₂ concentrations, and global carbon sinks. Standard metrics of this feedback assume that the response of land and ocean carbon uptake to CO₂ (concentration–carbon cycle feedback) and climate change (climate–carbon cycle feedback) combine linearly. This study...
Resource Type:: Article

Creator:: Somes, Christopher J., Schmittner, Andreas, and Altabet, Mark A.
Abstract:: Nitrogen (N) fixation by specialized microorganisms (diazotrophs) influences global plankton productivity because it provides the ocean with most of its bio-available N. However, its global rate and large-scale spatial distribution is still regarded with considerable uncertainty. Here we use a global ocean nitrogen isotope model, in comparison with δ15NO3 observations,...
Resource Type:: Article

Creator:: Goes, Marlos, Urban, Nathan M., Tonkonojenkov, Roman, Haran, Murali, Schmittner, Andreas, and Keller, Klaus
Abstract:: Current projections of the oceanic response to anthropogenic climate forcings are uncertain. Two key sources of these uncertainties are (1) structural errors in current Earth system models and (2) imperfect knowledge of model parameters. Ocean tracer observations have the potential to reduce these uncertainties. Previous studies typically consider each tracer...
Resource Type:: Article

Creator:: Buizert, Christo and Schmittner, Andreas
Abstract:: Glacial periods exhibit abrupt Dansgaard-Oeschger (DO) climatic oscillations that are thought to be linked to instabilities in the Atlantic meridional overturning circulation (AMOC). Great uncertainty remains regarding the dynamics of the DO cycle, as well as controls on the timing and duration of individual events. Using ice core data we...
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Creator:: Muglia, Juan and Schmittner, Andreas
Abstract:: Previous Paleoclimate Model Intercomparison Project (PMIP) simulations of the Last Glacial Maximum (LGM) Atlantic Meridional Overturning Circulation (AMOC) showed dissimilar results on transports and structure. Here we analyze the most recent PMIP3 models, which show a consistent increase (on average by 41 ± 26%) and deepening (663 ± 550 m)...
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Creator:: Schmittner, Andreas, Urban, Nathan M., Shakun, Jeremy D., Mahowald, Natalie M., Clark, Peter U., Bartlein, Patrick J., Mix, Alan C., and Rosell-Mele, Antoni
Abstract:: Assessing impacts of future anthropogenic carbon emissions is currently impeded by uncertainties in our knowledge of equilibrium climate sensitivity to atmospheric carbon dioxide doubling. Previous studies suggest 3 K as best estimate, 2–4.5 K as the 66% probability range, and non-zero probabilities for much higher values, the latter implying a...
Resource Type:: Article

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