SCOR/IMAGES Workshop on Past Ocean Circulation
20-23 March 2005
School of Earth and Atmospheric Sciences
Georgia Tech, Atlanta, Georgia, USA
The last glacial cycle is
characterized by rapid and dramatic changes in climate. While the origin of these rapid climate
changes is not yet resolved, many hypotheses involve changes in the Atlantic
ocean circulation. This idea was
driven by data from shell chemistry of foraminifera from deep sea sediments
which suggested that nutrients were arrayed differently in the Atlantic over
the course of these climate changes.
However, even for the Last Glacial Maximum the existing nutrient data is
insufficient to quantify an alternative ocean circulation state. When we turn to the rapid climate
change events that occurred during the last glacial cycle and over the course
of the deglaciation, the circulation scenarios based on nutrient
reconstructions alone only become more poorly constrained. However, there are several less widely applied methods for
assessing rates of paleo-ocean circulation which can be brought to bear on the
problem. These methods include
assessing deep water residence times from Pa/Th ratios in sediments, assessing
deep ocean ventilation from radiocarbon measurements in benthic corals and
foraminifera, reconstructing geostrophic flows using density gradients inferred
from oxygen isotope measurements and reconstructing the strength of near bottom
current speed from physical properties of deep sea sediments.
Working Group 123 was formed to bring together paleoceanographers with physical oceanographers and ocean modellers to determine what is necessary for an effective and realistic research plan which will lead to a robust reconstruction of past ocean circulation. We will most likely focus our efforts on the period covering the deglaciation and last glacial maximum (the last 30,000 years) in order to make full use of radiocarbon based proxies and dating.
In this workshop, we hope to (1) Assess the potential of
existing paleoceanographic proxies—to what extent can they constrain
scenarios of past ocean circulation if widely applied, (2) Assess the
sufficiency of existing data coverage, and (3) Determine whether a large scale
coordinated program is warranted, and what it might look like, based on the
above. We will bring together
experts in paleoceanographic data, physical oceanography and modeling (forward
and inverse approaches). The
workshop will include invited presentations, poster presentations and ample
time for discussion. The workshop
is limited to 50 participants.
However we strongly encourage the participation of junior and senior
scientists in a variety of relevant disciplines. A limited amount of travel support will be available.
Registration
(Deadline Jan 15)
For more information contact:
Sponsors:
