A recently proposed reduced-gravity model of the warm-water branch of the middepth meridional overturning circulation in a rectangular basin with a circumpolar connection is extended to include time dependence. The model describes the balance between gain of warm water through northward Ekman advection across the circumpolar current, loss of warm...
Climate models predict a gradual weakening of the North Atlantic meridional overturning circulation (MOC) during the twenty-first century due to increasing levels of greenhouse gas concentrations in the atmosphere. Using an ensemble of 16 different coupled climate models performed for the Fourth Assessment Report (AR4) of the Intergovernmental Panel on...
Paleoclimate records from glacial Indian and Pacific oceans sediments document millennial-scale fluctuations of subsurface dissolved oxygen levels and denitrification coherent with North Atlantic temperature oscillations. Yet the mechanism of this teleconnection between the remote ocean basins remains elusive. Here we present model simulations of the oxygen and nitrogen cycles that...
The floating ice shelf of Petermann glacier interacts directly with the ocean and is
thought to lose at least 80% of its mass through basal melting. Based on three opportunistic
ocean surveys in Petermann Fjord we describe the basic oceanography: the circulation
at the fjord mouth, the hydrographic structure beneath...
Due to lower sea levels during the Last Glacial Maximum (LGM), tidal energy dissipation was shifted from the shallow margins into the deep ocean. Here using a high-resolution tide model, we estimate that global energy fluxes below 200 m depth were almost quadrupled during the LGM. Applying the energy fluxes to...
Full Text:
Glacial
Ocean
Overturning]
[A.
Schmittner1,
J.
A.
M.
Green2,
S.-‐B
Due to lower sea levels during the Last Glacial Maximum (LGM), tidal energy dissipation was shifted from the shallow margins into the deep ocean. Here using a high-resolution tide model, we estimate that global energy fluxes below 200 m depth were almost quadrupled during the LGM. Applying the energy fluxes to...
Full Text:
mixing in a global circulation model
Glacial ocean overturning intensified by tidal mixing in a global
Because ocean circulation impacts global heat transport, understanding the relationship between deep ocean circulation and climate is important for predicting the ocean's role in climate change. A common approach to reconstruct ocean circulation patterns employs the neodymium isotope compositions of authigenic phases recovered from marine sediments. In this approach, mild...
Due to lower sea levels during the Last Glacial Maximum (LGM), tidal energy dissipation was shifted from the shallow margins into the deep ocean. Here using a high-resolution tide model, we estimate that global energy fluxes below 200 m depth were almost quadrupled during the LGM. Applying the energy fluxes to...
The long-term evolution of initially Gaussian eddies is studied in a reduced-gravity shallow-water model using both linear and nonlinear quasigeostrophic theory in an attempt to understand westward-propagating mesoscale eddies observed and tracked by satellite altimetry. By examining both isolated eddies and a large basin seeded with eddies with statistical characteristics...
The impact of mountains and ice sheets on the large-scale circulation of the world’s oceans is investigated in a series of simulations with a new coupled ocean–atmosphere model [Oregon State University–University of Victoria model (OSUVic)], in which the height of orography is scaled from 1.5 times the actual height (at...