Seasonal ventilation of the cavity beneath Filchner-Ronne Ice Shelf simulated with an isopycnic coordinate ocean model

Adrian Jenkins, David M. Holland, Keith W. Nicholls, Michael Schröder, Svein Østerhus

Research output: Contribution to journalArticle

Abstract

The ocean cavity beneath Filchner-Ronne Ice Shelf is observed to respond to the seasonal cycle of water mass production on the continental shelf of the southern Weddell Sea. Here we use a numerical model to investigate the propagation of newly formed shelf waters into the cavity. We find that the model reproduces the most distinctive features of the observed seasonality and offers a plausible explanation for those features. The most saline shelf waters are produced in the far west, where the inflow to the cavity peaks twice each year. The major peak occurs during the short period around midwinter when convection reaches full depth and the densest waters are generated. Once the surface density starts to decline, dynamic adjustment of the restratified water column leads to a gradual fall in the salinity at depth and a secondary peak in the inflow that occurs in summer at the western coast. Beneath the ice shelf the arrival of the wintertime inflow at the instrumented sites is accompanied by a rapid warming, while the slower decline in the inflow leads to a more gradual cooling. Water brought in by the secondary, summer peak flows mainly to the eastern parts of the cavity. Here the seasonality is suppressed because the new inflows mix with older waters that recirculate within a topographic depression. This pooling of waters in the east, where the primary outflow of Ice Shelf Water is generated, dampens the impact of seasonality on the local production of Weddell Sea Bottom Water.

Original languageEnglish (US)
JournalJournal of Geophysical Research: Space Physics
Volume109
Issue number1
StatePublished - Jan 15 2004

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land ice
ocean models
ventilation
ice shelf
Ice
Ventilation
cavity
inflow
cavities
Water
ocean
water
seasonality
dense water
shelves
peak flow
summer
bottom water
water mass
continental shelf

Keywords

  • Antarctic oceanography
  • Ice shelf-ocean interaction
  • Numerical modeling

ASJC Scopus subject areas

  • Oceanography
  • Astronomy and Astrophysics
  • Atmospheric Science
  • Space and Planetary Science
  • Earth and Planetary Sciences (miscellaneous)
  • Geophysics
  • Geochemistry and Petrology

Cite this

Seasonal ventilation of the cavity beneath Filchner-Ronne Ice Shelf simulated with an isopycnic coordinate ocean model. / Jenkins, Adrian; Holland, David M.; Nicholls, Keith W.; Schröder, Michael; Østerhus, Svein.

In: Journal of Geophysical Research: Space Physics, Vol. 109, No. 1, 15.01.2004.

Research output: Contribution to journalArticle

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