Articles | Volume 8, issue 1
Earth Syst. Sci. Data, 8, 191–198, 2016
https://doi.org/10.5194/essd-8-191-2016
Earth Syst. Sci. Data, 8, 191–198, 2016
https://doi.org/10.5194/essd-8-191-2016

  12 May 2016

12 May 2016

Mapping the Antarctic Polar Front: weekly realizations from 2002 to 2014

Natalie M. Freeman and Nicole S. Lovenduski Natalie M. Freeman and Nicole S. Lovenduski
  • Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, USA

Abstract. We map the weekly position of the Antarctic Polar Front (PF) in the Southern Ocean over a 12-year period (2002–2014) using satellite sea surface temperature (SST) estimated from cloud-penetrating microwave radiometers. Our study advances previous efforts to map the PF using hydrographic and satellite data and provides a unique realization of the PF at weekly resolution across all longitudes (doi:10.1594/PANGAEA.855640). The mean path of the PF is asymmetric; its latitudinal position spans from 44 to 64° S along its circumpolar path. SST at the PF ranges from 0.6 to 6.9 °C, reflecting the large spread in latitudinal position. The average intensity of the front is 1.7 °C per 100 km, with intensity ranging from 1.4 to 2.3 °C per 100 km. Front intensity is significantly correlated with the depth of bottom topography, suggesting that the front intensifies over shallow bathymetry. Realizations of the PF are consistent with the corresponding surface expressions of the PF estimated using expendable bathythermograph data in the Drake Passage and Australian and African sectors. The climatological mean position of the PF is similar, though not identical, to previously published estimates. As the PF is a key indicator of physical circulation, surface nutrient concentration, and biogeography in the Southern Ocean, future studies of physical and biogeochemical oceanography in this region will benefit from the provided data set.

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Short summary
The Antarctic Polar Front (PF) is an important physical and biogeochemical divide in the Southern Ocean, delineating distinct zones of temperature, nutrients and biological communities. Our study learns from and advances previous efforts to locate the PF via satellite by avoiding cloud contamination and providing circumpolar realizations at high spatio-temporal resolution. These realizations are consistent with concurrent in situ PF locations and previously published climatological PF positions.