Southern ocean controls on current ice shelf evolution. Annual progress report, September 1, 1993--August 31, 1994

• Main Authors: Hellmer, H.H., Jacobs, S.S.
• Language: unknown
• Published: 2018
• Subjects: 54 ENVIRONMENTAL SCIENCES; OCEANIC CIRCULATION; GENERAL CIRCULATION MODELS; SURFACE WATERS; SEASONAL VARIATIONS; CLIMATIC CHANGE; ENVIRONMENTAL IMPACTS; PROGRESS REPORT; ICE CAPS; BOREHOLES; SALINITY; Southern Ocean; Ross Ice Shelf; Siple; Roosevelt Island; Siple Coast; Ice Shelf; Ice Shelves
• Online Access: http://www.osti.gov/servlets/purl/10173336; https://www.osti.gov/biblio/10173336; https://doi.org/10.2172/10173336

A seasonal cycle of shelf water temperatures and salinities observed at the eastern Ross Ice Shelf edge was used to force a two-dimensional thermohaline circulation model adapted to two different sub-ice cavity paths around Roosevelt Island. Model results verified by current meter measurements reveal that shelf water flowing into the cavity west of Roosevelt Island might follow a sub-ice path with nearly constant water column thickness of 200 m. This would largely exclude the grounding line of the northern Siple Coast from the contact with open ocean water masses. In contrast to the forcing with time-independent summer profiles, seasonal forcing causes a higher spatial and temporal variability of the cavity`s circulation and property distribution. At the model`s open boundaries the intermitted inflow of shelf water displaces the meltwater outflow originating from the interior ice shelf base to greater depth and initiates an additional shallow meltwater plume. The average melting along the ice shelf base increases from 0.07 m/a to 0.38.m/a due to seasonality in shelf water characteristics, and to 2.3 m/a, if we introduce a 100-year temperature rise of 1{degree}C. The rate decreases, if salinity simultanously decreases; a possible scenario, if the enhanced meltwater outflow mixes with shelf water in front of the ice shelves.