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Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 42 (2015): 7648–7654, doi:10.1002/2015GL064944., The mass loss at Nioghalvfjerdsbræ is primarily due to rapid submarine melting. Ocean data obtained from beneath the Nioghalvfjerdsbræ ice tongue show that melting is driven by the presence of warm (1°C) Atlantic Intermediate Water (AIW). A sill prevents AIW from entering the cavity from Dijmphna Sund, requiring that it flow into the cavity via bathymetric channels to the south at a pinned ice front. Comparison of water properties from the cavity, Dijmphna Sund, and the continental shelf support this conclusion. Overturning circulation rates inferred from observed melt rates and cavity stratification suggest an exchange flow between the cavity and the continental shelf of 38mSv, sufficient to flush cavity waters in under 1 year. These results place upper bounds on the timescales of external variability that can be transmitted to the glacier via the ice tongue cavity., NASA Grant Number: NNX13AK88G, NSF Grant Number: OCE-1434041, 2016-03-22

Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 42 (2015): 7648–7654, doi:10.1002/2015GL064944., The mass loss at Nioghalvfjerdsbræ is primarily due to rapid submarine melting. Ocean data obtained from beneath the Nioghalvfjerdsbræ ice tongue show that melting is driven by the presence of warm (1°C) Atlantic Intermediate Water (AIW). A sill prevents AIW from entering the cavity from Dijmphna Sund, requiring that it flow into the cavity via bathymetric channels to the south at a pinned ice front. Comparison of water properties from the cavity, Dijmphna Sund, and the continental shelf support this conclusion. Overturning circulation rates inferred from observed melt rates and cavity stratification suggest an exchange flow between the cavity and the continental shelf of 38mSv, sufficient to flush cavity waters in under 1 year. These results place upper bounds on the timescales of external variability that can be transmitted to the glacier via the ice tongue cavity., NASA Grant Number: NNX13AK88G, NSF Grant Number: OCE-1434041, 2016-03-22

The mass loss at Nioghalvfjerdsbræ is primarily due to rapid submarine melting. Ocean data obtained from beneath the Nioghalvfjerdsbræ ice tongue show that melting is driven by the presence of warm (1°C) Atlantic Intermediate Water (AIW). A sill prevents AIW from entering the cavity from Dijmphna Sund, requiring that it flow into the cavity via bathymetric channels to the south at a pinned ice front. Comparison of water properties from the cavity, Dijmphna Sund, and the continental shelf support this conclusion. Overturning circulation rates inferred from observed melt rates and cavity stratification suggest an exchange flow between the cavity and the continental shelf of 38mSv, sufficient to flush cavity waters in under 1 year. These results place upper bounds on the timescales of external variability that can be transmitted to the glacier via the ice tongue cavity.

An extraordinary sea ice tongue developed near 85 degrees E over a period of 30 days in April-May 2002. The ice tongue extended to the north more than 800 km from the surrounding ice edge and covered an area greater than 200,000 km 2. Satellite measurements of ice extent and roughness characteristics demonstrate that the tongue persisted as a distinct feature throughout the winter. Remote sensing observations between 1978 and 2004 confirm that ice tongues occur frequently at this location, although the 2002 tongue was particularly pronounced. We show that ocean currents and winds conspire to favor the development of ice tongues at this location. Mean streamlines of the southern part of the Antarctic Circumpolar Current turn sharply to the north near 85 degrees E after passing through the Princess Elisabeth Trough. The edge and northern limit of the ice tongue correspond well with the pattern of mean streamlines. Mean winds in April - May have a dominant southerly component in this location, favoring offshore advection of ice; year- to- year variability in the prominence of the tongue is largely caused by variations in the wind, with northerly ( southerly) anomalies inhibiting ( promoting) development of a sea ice tongue. Ice drift is strongly northward along the axis of the tongue, suggesting the feature is formed by advection of ice from the south rather than by in situ thermodynamic ice formation. The northward current and sea ice tongue at 85 degrees E are associated with higher biomass at all trophic levels than observed elsewhere in east Antarctica.

An extraordinary sea ice tongue developed near 85 degrees E over a period of 30 days in April-May 2002. The ice tongue extended to the north more than 800 km from the surrounding ice edge and covered an area greater than 200,000 km 2. Satellite measurements of ice extent and roughness characteristics demonstrate that the tongue persisted as a distinct feature throughout the winter. Remote sensing observations between 1978 and 2004 confirm that ice tongues occur frequently at this location, although the 2002 tongue was particularly pronounced. We show that ocean currents and winds conspire to favor the development of ice tongues at this location. Mean streamlines of the southern part of the Antarctic Circumpolar Current turn sharply to the north near 85 degrees E after passing through the Princess Elisabeth Trough. The edge and northern limit of the ice tongue correspond well with the pattern of mean streamlines. Mean winds in April - May have a dominant southerly component in this location, favoring offshore advection of ice; year- to- year variability in the prominence of the tongue is largely caused by variations in the wind, with northerly ( southerly) anomalies inhibiting ( promoting) development of a sea ice tongue. Ice drift is strongly northward along the axis of the tongue, suggesting the feature is formed by advection of ice from the south rather than by in situ thermodynamic ice formation. The northward current and sea ice tongue at 85 degrees E are associated with higher biomass at all trophic levels than observed elsewhere in east Antarctica.

An extraordinary sea ice tongue developed near 85 degrees E over a period of 30 days in April-May 2002. The ice tongue extended to the north more than 800 km from the surrounding ice edge and covered an area greater than 200,000 km 2. Satellite measurements of ice extent and roughness characteristics demonstrate that the tongue persisted as a distinct feature throughout the winter. Remote sensing observations between 1978 and 2004 confirm that ice tongues occur frequently at this location, although the 2002 tongue was particularly pronounced. We show that ocean currents and winds conspire to favor the development of ice tongues at this location. Mean streamlines of the southern part of the Antarctic Circumpolar Current turn sharply to the north near 85 degrees E after passing through the Princess Elisabeth Trough. The edge and northern limit of the ice tongue correspond well with the pattern of mean streamlines. Mean winds in April - May have a dominant southerly component in this location, favoring offshore advection of ice; year- to- year variability in the prominence of the tongue is largely caused by variations in the wind, with northerly ( southerly) anomalies inhibiting ( promoting) development of a sea ice tongue. Ice drift is strongly northward along the axis of the tongue, suggesting the feature is formed by advection of ice from the south rather than by in situ thermodynamic ice formation. The northward current and sea ice tongue at 85 degrees E are associated with higher biomass at all trophic levels than observed elsewhere in east Antarctica.