Temperature investigation and modeling on the Filchner-Ronne Ice Shelf, Antarctica

Abstract

ABSTRACT. During Considering mass and energy conservation, a basal layer of 350 m of marine icc was calculated with thermal properties, depending on salinity and temperature.In areas with strong basal freezing, almost isothermal depth profiles in tht' marine ice layer arc dt'rived. further downstream, in areas of basal melting, a ncarly cubic tempcrarure--depth profile is observed.

Modelling the influence of marine ice on the dynamics of an idealised ice shelf

“…This is likely due to a slower rate of marine ice accretion at that location, which is not the case throughout the entire shelf. Grosfeld and Thyssen (1994) used a 2-D thermal model, in combination with a partial temperature profile collected at a different location, to investigate how the shape of thermal profiles may vary throughout the ice shelf. They concluded that an 'S-shaped' thermal profile associated with a isothermal basal layer, as seen in the Amery IS, likely forms where basal accretion rates are high (up to 2 m a −1 in the Filchner-Ronne IS), and the ice shelf is not able to thermally equilibrate as large amounts of warm ice are added to the base.…”

“…Porosity and tortuosity are also likely to affect the distribution of heat through the ice shelf. Grosfeld and Thyssen (1994) suggest that a 'slushy' layer of higher porosity has an insulating effect in the marine ice, preventing thermal equilibration and allowing the influx of heat from direct contact with sea water. However, ice with a high level of tortuosity and interconnectivity in its pore spaces will experience a greater influx of heat from the ocean.…”

“…As outlined in the Introduction, our knowledge of the in situ temperature, chemical composition and microstructural characteristics of marine ice are limited. We have chosen two representative thermal profiles for a shelf with a marine ice layer, but as Grosfeld and Thyssen (1994) suggest in their discussion of the Filchner-Ronne IS, it is possible for the thermal profile to vary within a shelf as the marine ice accretion rate changes. Our 'isothermal' profile is also a simplification of the more S-shaped profile seen in the Amery IS.…”