CGD Seminar Series - Eisenman

Title: Iceberg dynamics in modern and glacial oceans

Speaker: Ian Eisenman, Scripps Institution of Oceanography

Date: Tuesday, 22 January 2019

Time: 11 am - 12 pm

Location: Mesa Lab, Main Seminar Room, ML-132

Abstract: Icebergs released from the Greenland and Antarctic ice sheets drift in the modern high-latitude oceans, releasing meltwater as they go and capsizing when their shapes become unstable. The role that they play in the global ocean circulation and climate depends crucially on the iceberg drift trajectories, which often are interpreted using an empirical rule-of-thumb to account for the influence of winds and ocean currents. The flux of icebergs from Greenland and Antarctica has recently increased and is projected to further increase in the future, perhaps dramatically. This raises analogies to the Heinrich events of the last glacial period, when there were massive discharges of icebergs from the Laurentide Ice Sheet which are believed to have drifted enigmatically long distances in the North Atlantic and disrupted the global climate. In this talk, I will present several results related to an idealized model of iceberg drift and decay that we have recently developed. These results include (i) a mathematical derivation and physical explanation of the empirical rule-of-thumb for how winds and ocean currents influence iceberg drift, (ii) the identification and correction of substantial flaws in a standard representation of iceberg capsizing that has been used in dozens of previous modeling studies, and (iii) a proposed physical mechanism involving sea ice and wave erosion that could have substantially increased the lengths of iceberg drift trajectories during glacial Heinrich events, with implications regarding the impact on the climate system if a large iceberg discharge event occurs in the future.

For more information, contact Teresa Foster, teresaf@ucar.edu, 303.497.1741

Building:

Room Number: 
ML-132

Type of event:

Will this event be webcast to the public by NCAR|UCAR?: 
Yes - ML-Main Seminar Room - http://ucarconnect.ucar.edu/live
Announcement Timing: 
Monday, January 21, 2019 to Tuesday, January 22, 2019
Calendar Timing: 
Tuesday, January 22, 2019 - 11:00am to 12:00pm

Posted by Teresa Foster at ext. 1741, teresaf@ucar.edu

Random Profile

SR RES ASSOC - CAS

Quick Facts

NCAR is managed by the nonprofit University Corporation for Atmospheric Research on behalf of NSF and the UCAR university community.

  • NCAR is not a federal agency and its employees are not part of the federal personnel system.
  • Our activities complement those of the federal agencies and we work closely with them.

More about us