Are ice shelf fronts a topographic barrier for barotropic currents?

Speaker: 
Nadine Steiger (Ocean Modeling)
Seminar Date: 
29. October 2019 - 11:15 - 11:45
Location: 
Lecture room, Ground Floor, NERSC

Ice shelves in West Antarctica are thinning at an increasing rate due to the inflow of relatively warm Circumpolar Deep Water into the ice shelf cavities. This warm water from off the continental shelf flows southward towards the ice shelves through submarine troughs incised into the continental shelf. Observations in front of Getz Ice Shelf suggest that 90% of the volume transport and 65% of the temperature transport is linked to the barotropic component of the southward current which follows f/H-contours. Ones this current reaches the several hundred meter deep ice shelf front, it encounters a large discontinuity in the water column where it has to cross f/H-contours.

I will present ongoing work with MITgcm to study the passage of a barotropic current across an ice shelf front. The idealized setup is a v-shaped channel through which a forced barotropic current flows towards an ice shelf front. The ice shelf does – in many of the experiments – not interact with the ocean thermodynamically but acts as a dynamical barrier. The different experiments contain a variation in trough and ice shelf geometry, changes in forcing and the inclusion of subglacial melt.