Two-dimensional prognostic experiments for ice streams in the Arctic.

      Аннотация: The prognostic experiments were carried out for the three fast flowing ice streams on the south side of the Academy of Sciences Ice Cap in the Komsomolets Island, Severnaya Zemlya archipelago. The prognostic experiments are based on the inversions for basal friction coefficients that were performed by a 2D ice flow line thermo-coupled model and with the Tikhonov regularization method. Modelled ice temperature distributions in the cross-sections have been obtained using the ice surface temperature histories that were inverted previously from the bore hole temperature profiles. The prognostic experiments reveal both ice mass and ice stream extents decline for the reference time-independent mass balance. Exactly, grounding line retreats (a) along C-C' flow line from about 43 km to about 37 km (the distance from the summit) (b) along B-B' flow line from about 40 km to about 30 km (c) along D-D' flow line from about 41 km to about 32 km - during considered time period of 500 years and in the assumption of time-independent mass balance. In general, the modelled histories are in agreement with the observations of sea ice extent and thickness showing a continual ice decline in the Arctic.

Ключевые слова: Arctic, Ice Stream, Ice Shelf, friction coefficient inversion, 2D flow line model, Tikhonov’s regularization method, prognostic experiment, grounding line