Observed Variability in the Ross Ice Shelf Ocean Cavity Circulation: A Two-Year-Long Hydrographic Timeseries

Abstract:

We present two years of hydrographic data from beneath the centre of the Ross Ice Shelf cavity. Access was via the New Zealand Antarctic Research Institute funded Aotearoa New Zealand Ross Ice Shelf Programme Borehole which drilled through 367 m of snow and ice in late 2017. The data include temperature, salinity and currents. These data support the general picture identified from initial intense hydrographic profile work. In addition these new data provide insight into the consistency of mid-water column variability throughout the annual cycle. Large-scale eddy features are apparent in the data with around five passing by the observation point per year. There are also sporadic singular events that would the disrupt the water column structure for several days at a time. The data also enable diagnosis of mixing in the basal boundary-layer which partly correlates with the tides.