Science-of-Opportunites aboard Oden: Two NSF Supported Programs

Ocean-Atmosphere-Ice Interactions and Changes

PI: Xiaojun Yuan; Co-PI: Sharon E. Stammerjohn

Bio-Physical Variability in Regions of the Southern Ocean with Contrasting Climatic Response - The eastern Amundsen & Ross Seas

PI: Raymond N. Sambrotto; Co-PI: Xiaojun Yuan, Sharon E. Stammerjohn

Program Description | Sponsors | Principal Investigators | International Collaborators | Data | Publications

Oden, Swedish Ice Breaker, was charted by NSF to break the shipping channel at the McMurdo Sound from 2006-2010. On her way to the Ross Island, she provided science-of-opportunities for scientists from US and Sweden conducting physical and biogeochemical sampling in the Amundsen Sea and Ross Sea.

Program Description

The overarching objective of these programs was to investigate physical and biogeochemical variability in the Amundsen and Ross Seas, two regions which show contrasting responses to climate change. Specifically, we addressed the extent of CDW intrusions along the shelf, assess freshwater inputs from glacial melt and changes in sea ice production, and examined the biogeochemical fluxes in response to the different physical environments, all in the context of surface forcing associated with large-scale climate patterns.

The region from the western Antarctic Peninsula to the Ross Sea is one of the least sampled in the Southern Ocean. It also is undergoing some of the most conspicuous changes that have been observed at high latitudes. These changes include the thinning and collapsing of ice shelves and contrasting regional changes in the duration of the sea ice season. The Circumpolar Deep Water (CDW), a water mass of particular significance to physical and biological dynamics, regionally floods the continental shelf, directly threatening the stability of ice shelves, and hence the ice sheet. Some of these important variables appear to be influenced by large-scale climate forcing associated with El Nino/Southern Oscillation (ENSO) and the Antarctic Dipole (ADP). Linking the climate sensitive aspects of this region to the changes in local ocean physics and biogeochemical fluxes was a key focus of these studies. Access to this region was made possible by a five year, US-Swedish cooperative agreement (starting 2007-08) using the Class 1A Swedish icebreaker, Oden that will pass through the southeast Pacific region on her way to the annual break-in of the McMurdo Ship Channel in the Ross Sea.

Our programs were a part of US/Swedish interdisciplinary collaboration during IPY. In austral summers of 2007-08 and 2008-09, we conducted physical and biogeochemical sampling on board of Oden.

Sampling stations during oso07-08 and oso08-09.


	National Science Foundation
	United States of America

	Swedish Polar Research Secretariat
	Ministry of Education and Research

Principal Investigators

	Xiaojun Yuan
        Lamont Associate Research Professor	
	Lamont-Doherty Earth Observatory of Columbia University
	The United States

	Raymond N. Sambrotto	
 	Lamont Associate Research Professor	
	Lamont-Doherty Earth Observatory of Columbia University
	The Unites States

  	Sharon E. Stammerjohn
	Senior Research Associate	
	Institute of Arctic and Alpine Research 
	University of Colorado, Boulder, Colorado 
	The United States

International Collaborators

Swedish physicists Drs. Bjork and Wahlin.

Swedish biogeochemists Drs. Chierici and Fransson



Most data have been submitted to NODC under accession 0106522 and 0088873.

oso06 XBT data

oso07 XBT data

oso08 XBT data

oso07-08 XCTD data

oso08-09 XCTD data

oso07-08 Conventional CTD data

oso08-09 CTD data (NODC accession 0088873)

oso08-09 LADCP data

oso07-08 and oso08-09 bottle data


Wahlin, A. K., X. Yuan, G. Bjork and C. Nohr (2010), Inflow of Warm Circumpolar Deep Water 
	in the Central Amundsen Shelf. J. Phys. Oceanogr., 40(6): 1427-1434, DOI: 

Yuan, X., R. Sambrotto, S. Stammerjohn, W. Smethie, Goran Bjork, Anna K. Wahlin, C. Li, 
	Spatial Variability of Water Masses on the Amundsen Sea Shelf. Submitted to JGR-Oceans.

Wahlin, A. K, R. D. Muench, L. Ameborg, G. Bjork, H. K. Ha, S. H. Lee, H. Alsen (2012), 
	Some Implication of Ekman Layer Dynamics for Cross Shelf Exchange in the Amundsen Sea. 
	Submitted to JPO.

This page is maintained by Xiaojun Yuan ( The last update was on 5/3/2012