A short term characterisation of wind and temperature over Maitri, East Antarctica

Polar Science is gaining increased importance in Climate Change studies because of the profound influence Polar Climatology has on the Global Climate. Research shows that Antarctica seems to be warming around the edges and cooling at the center at the same time. East Antarctica is climatologically colder than west Antarctica because of its higher elevation. A short term characterization of wind and the temperature over Maitri is attempted in this paper. Maximum and Minimum temperatures showed a tendency to decrease with winter contributing the most to the change. The Wind Directions were predominantly South-South-Easterly in summer and autumn and South-Easterly in winter and spring, with katabatic winds showing the maximum frequency in autumn. The wind speeds were found to be most variable in winter. Greater contributions to the wind chill temperatures were found from the winds, with the tendency for change being more prominent in the transition seasons.

Persistent, Extensive Channelized Drainage Modeled Beneath Thwaites Glacier, West Antarctica

Subglacial hydrology is a leading control on basal friction and the dynamics of glaciers and ice sheets. At low discharge, subglacial water flows through high-pressure, sheet-like systems that lead to low effective pressures. However, at high discharge, subglacial water melts the overlying ice into localized channels that efficiently remove water from the bed, thereby increasing effective pressure and basal friction. Recent observations suggest channelized subglacial flow exists beneath Thwaites Glacier, yet it remains unclear if stable channelization is feasible in West Antarctica, where surface melting is nonexistent and water at the bed is limited. Here, we use the MPAS-Albany Land Ice model to run a suite of over 130 subglacial hydrology simulations of Thwaites Glacier across a wide range of physical parameter choices to assess the likelihood of channelization. We then narrow our range of viable simulations by comparing modeled water thicknesses to previously observed radar specularity content, which indicates flat, spatially extensive water bodies at the bed. In all of our data-compatible simulations, stable channels reliably form within 100–200 km of the grounding line, and reach individual discharge rates of 35–110 m3 s−1 at the ice-ocean boundary. While only one to two channels typically form across the 200 km width of the glacier in our simulations, their high efficiency drains water across the entire lateral extent of the glacier. No simulations resembled observed specularity content when channelization is disabled. Our results suggest channelized subglacial hydrology has two consequences for Thwaites Glacier dynamics: (i) amplifying submarine melting of the terminus and ice shelf, while (ii) simultaneously raising effective pressure within 100 km of the grounding line and increasing basal friction. The distribution of effective pressure implied from our modeling differs from parameterizations typically used in large-scale ice sheet models, suggesting the development of more process-based parameterizations may be necessary.