EOS, Transactions, AGU,
1999 Fall Meeting, Vol. 80, No. 46, November 16, 1999, page F11
Tracing
Water and Sediment Transport in Simulations of Present-day, Glacial, and Interglacial
Ocean Circulation Regimes
Earth System Science Center, Pennsylvania State University,
University Park, PA 16802-2711
Modeling the global ocean
thermohaline conveyor at present, at the Last Glacial Maximum, and at a subsequent
meltwater event is revisited using a combination of MOM-2 ocean global circulation
model, a sediment transport model, and a water transport visualization techniques
employing particles and additional tracers. The modeled changes of sediment
deposition rates, linked to the changes of the global deep-ocean thermohaline
circulation, provide a better understanding of the glacial-to-interglacial variability
of the conveyor dynamics, and help to identify the regions of the world ocean
that are most sensitive to the glacial and meltwater impacts. In addition to
the well-known local changes of the conveyor in the Atlantic Ocean during the
last glaciation and subsequent meltwater events, the simulations show the global
character of these impacts, detected as far from the North Atlantic as the Indian
and the southwestern Pacific Oceans. As deep convection plays crucial role in
the global thermohaline conveyor and regulates the changes of the conveyor on
time scale of years to millennia, different tracer mixing schemes were tested
to address the sensitivity of the conveyor dynamics on the millennial time scale.
Based on these simulations, we challenge the idea of a global conveyor-like
deep flow strongly connecting the surface waters of northern parts of the North
Atlantic and North Pacific Oceans at Holocene/modern, or glacial, or meltwater
intervals.
Left part; click
on the poster to see the A0 version (222 KB).
Right part; click on the poster
to see the A0 version (264 KB).
