Skip to main content
Article thumbnail
Location of Repository

The circulation in the Argentine Basin exhibits extreme levels of variability. In altimeter data and model

By Wilbert Weijer and Sarah T. Gille


Observations of the sea surface height in the Argentine Basin indicate that strong variability occurs on a time scale of 20�30 days. The aim of this study is to determine the physical processes responsible for this variability. First, results are presented from two statistical techniques applied to a decade of altimetric data. A complex empirical orthogonal function (CEOF) analysis identifies the recently discovered dipole mode as the dominant mode of variability. A principal oscillation pattern (POP) analysis confirms the existence of this mode, which has a period of 25 days. The second CEOF displays a propagating pattern in the northern Argentine Basin, plus a rotating dipole in the southwest corner. The POP analysis identifies both patterns as individual modes, with periods of 30 and 20 days, respectively. Second, the barotropic normal modes of the Argentine Basin are studied, using a shallow-water model capturing the full bathymetry of the basin. Coherences between the spatial patterns of these modes and altimeter data suggest that several of the basin modes are involved in the observed variability. This analysis implies that the 20-day mode detected by recent bottom-pressure measurements is a true barotropic mode. However, the 25-day variability, as found in altimeter data, cannot be directly attributed to the excitation of a free Rossby basin mode. This study indicates that the results of several apparently conflicting observations of th

Year: 2005
OAI identifier: oai:CiteSeerX.psu:
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.