American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 267342 bytes)    Cited by

GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L11603, doi:10.1029/2005GL022727, 2005

Impact of the Southern Annular Mode on Southern Ocean circulation and biology

Nicole S. Lovenduski

Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA


Nicolas Gruber

Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA


Abstract

We investigate the impact of the Southern Annular Mode (SAM) on surface wind, sea surface temperature (SST), and surface chlorophyll concentration on intraseasonal to interannual timescales in the Southern Ocean using 8-day average satellite observations. Positive phases of the SAM are associated with enhanced westerly winds over the Antarctic Zone (AZ) and Polar Frontal Zone, driving increased equatorward Ekman transport and cold SST anomalies in these regions. Positive SAM is also associated with easterly wind and warm SST anomalies in the Subtropical Zone. South of the Antarctic Polar Front (APF), chlorophyll concentration anomalies are positively correlated with the SAM, however this correlation is negative north of the APF. We suggest that the positive correlation in the AZ is due to the increased supply of iron by upwelling, while the negative correlation north of the APF is caused by stronger light limitation as a consequence of deeper mixed layers.

Received 15 February 2005; accepted 5 May 2005; published 8 June 2005.

Index Terms: 4215 Oceanography: General: Climate and interannual variability (1616, 1635, 3305, 3309, 4513); 4273 Oceanography: General: Physical and biogeochemical interactions; 4275 Oceanography: General: Remote sensing and electromagnetic processes (0689, 2487, 3285, 4455, 6934); 4806 Oceanography: Biological and Chemical: Carbon cycling (0428).

Read Full Article (file size: 267342 bytes)    Cited by

Citation: Lovenduski, N. S., and N. Gruber (2005), Impact of the Southern Annular Mode on Southern Ocean circulation and biology, Geophys. Res. Lett., 32, L11603, doi:10.1029/2005GL022727.