AGU Chapman Conference on Abrupt Climate Change
Harunur Rashid, Byrd Polar Research Center, The Ohio State University, Columbus, OH
Lonnie Thompson, Byrd Polar Research Center, The Ohio State University, Columbus, OH
Leonid Polyak, Byrd Polar Research Center, The Ohio State University, Columbus, OH
NSF, Ocean Leadership, Climate Water Carbon Initiative-OSU
The main objective of the proposed conference on Abrupt Climate Change is to bring together a diverse group of researchers who deal with paleo-proxy records such as ice cores, corals, marine sediments, terrestrial (lakes and speleothems) archives, and coupled ocean-atmosphere climate models to discuss recent advances in understanding the mechanisms of abrupt climate changes. Since the discovery of the Dansgaard-Oeschger events in Greenland ice cores and their subsequent cousins in the marine sediments of the North Atlantic, search for these abrupt, millennial-scale events across the globe has been intensified. A good compilation of these abrupt climate events are given by Voelker et al. (2002). Since then, the number of paleoclimatic records has increased with most Northern Hemisphere records showing teleconnections with the D/O cycles in Greenland. However, the evidence for the abrupt climate change from the Southern Hemisphere is not clear although there appears to be a one-to-one correlation of the new EDML records of Antarctica with Greenland.
Marine and terrestrial paleoclimate records from the Southern Hemisphere are sparse and do not have enough temporal resolution to characterize the relevant timescales of climate variability. The paleo-records from the northern tropics and subtropics mainly show concordant climate changes with those in the North Atlantic, while asynchronous and even anti-correlated phenomena are exhibited in records from the Southern Hemisphere. For example, the Indian and East Asian monsoon systems seem to correlate with the North Atlantic climate, whereas the South American monsoon seems to operate differently. Furthermore, paleo-proxy records from the equatorial Pacific are characterized by a complex pattern of abrupt climate change that borrows elements from both the Northern and Southern Hemisphere end-members.
Three mechanisms were invoked to explain these abrupt climate changes: (a) freshwater forcing in which meltwater input from the circum-North Atlantic ice-sheets disrupts the meridional overturning circulation (MOC) by preventing the formation of North Atlantic Deep Water (NADW) in the Nordic seas; (b) sea-ice extent in which the albedo effect through altering the local and global energy and thus insulating the ocean from the atmosphere by cutting off the heat and moisture supply; and (c) tropical forcing which calls for a combination of the orbital configuration, El Nio-Southern Oscillation (La Nia) and sea-surface temperature (SST) conditions.
A number of outstanding scientific questions regarding Abrupt Climate Change include:
We invite contributions dealing with any aspect of Abrupt Climate Change, including the numerical models which incorporate proxy records as well as idealized models. Abstracts are solicited for any topic relevant to the above or other questions relating to Abrupt Climate Change.
A Chapman conference is uniquely suited to fruitful discussion of existing records, strategies to acquire new records and research priorities, and of crosscutting science issues: a group of manageable size that includes observational and modeling expertise across sub-disciplines rarely occurs in any other venue.
The meeting will span five days, with Friday afternoon off (see below for the planned field trip). The schedule is designed to maximize discussion and debate opportunities, and to make the meeting accessible to a broad audience. Each meeting day will consist of a morning and afternoon session, beginning with the morning oral session and poster session in the afternoon, covering the main focus areas:
The meeting will finish with a closing session to sum up the meeting and consider future directions. Each session from 1-5 above will include four invited talks to introduce the key issues, followed by open discussions moderated by the program committee, and brief poster presentations. There will be one poster session per day for other attendees to present their work except on Friday.
During the LGM Columbus, Ohio was covered by the Scioto Lobe of the Laurentide Ice-Sheet, which reached the Appalachian Plateau to the east. There it disrupted drainage, formed ice-marginal lakes, end moraines, and ice-contact topography (kames) and outwash terraces. The objective of the half-day field trip is to understand the development of these terrestrial features which are dominated by till plain, end moraines and outwash and ice-contact deposits. We plan to make several stops to examine till and outwash deposits. These will enhance our understanding of the Quaternary history of the region and help us visualize changes beneath the ice and at the ice margin.
120-150 including 25-35 graduate students. Support is anticipated for some postdocs and graduate students; details to follow.
Abrupt climate change, freshwater forcing, meridional overturning circulation, sea-ice and their impact in abrupt climate change, ice cores, paleo-monsoon, paleo-ENSO, ice-sheet dynamics, climate system and theory, general circulation models, and collapse of the past civilization.
15-19 June 2009
A room block has been reserved at the University Plaza Hotel for the discounted conference rate of $99.00 per night, which includes a complimentary breakfast buffet daily, free transportation within a three mile radius, and free wireless internet. Also included with your hotel room is a complimentary Business Center, Outdoor Pool and Fitness Center..Reservations can be made online with the promotional code AGU. To make reservations by phone call toll free in the US: +1+877-677-5292 and mention the Group Code: AGU. Outside the U.S call: +1+614-267-7461. The cut-off date for reservations is 20 May. After this date the group rate and availability cannot be guaranteed.
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