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On the Variability of Antarctic Circumpolar Current Fronts Inferred from 1992-2011 Altimetry*.
- Source :
- Journal of Physical Oceanography; Dec2014, Vol. 44 Issue 12, p3054-3071, 18p
- Publication Year :
- 2014
-
Abstract
- Antarctic Circumpolar Current (ACC) fronts, defined as water mass boundaries, have been known to respond to large-scale atmospheric variabilities, especially the Southern Hemisphere annular mode (SAM) and El Niño-Southern Oscillation (ENSO). Distinct patterns of localized variability in meridional front displacements during 1992-2011 are derived from the analysis of satellite sea surface height data. Major basin-scale differences are found between the southeast Pacific (150°-90°W) and the southeast Indian (75°-150°E) sectors of the ACC. Frontal positions in the southeast Pacific show large year-to-year meridional fluctuations, attributed mostly to ENSO and in part SAM, and no apparent seasonal cycles or long-term trends. In contrast, summer (winter) frontal locations in the southeast Indian extend farther to the south (north) of their long-term mean distribution. A southward drift of ACC fronts is indicated over the Indian sector during the past two decades. This long-term shift is not directly related to the atmospheric variabilities, but this is most likely in response to changes in large-scale ocean circulation, in particular to the poleward expansion of the Indian subtropical gyre. The existence of these localized, contrasting variability patterns suggests that a circumpolar-averaging analysis could possibly smooth out a local climate signal, with an emphasis on a basin-scale investigation for climate studies in the Southern Ocean. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00223670
- Volume :
- 44
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Journal of Physical Oceanography
- Publication Type :
- Academic Journal
- Accession number :
- 99708102
- Full Text :
- https://doi.org/10.1175/JPO-D-13-0217.1