Open AccessModeling the basal melting and marine ice accretion of the Amery Ice Shelf
Author(s) -
GaltonFenzi B. K.,
Hunter J. R.,
Coleman R.,
Marsland S. J.,
Warner R. C.
Publication year - 2012
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2012jc008214
Subject(s) - ice shelf , geology , sea ice , accretion (finance) , sea ice growth processes , antarctic sea ice , oceanography , ice divide , pancake ice , arctic ice pack , sea ice thickness , geomorphology , cryosphere , physics , astrophysics
The basal mass balance of the Amery Ice Shelf (AIS) in East Antarctica is investigated using a numerical ocean model. The main improvements of this model over previous studies are the inclusion of frazil formation and dynamics, tides and the use of the latest estimate of the sub‐ice‐shelf cavity geometry. The model produces a net basal melt rate of 45.6 Gt year −1 (0.74 m ice year −1 ) which is in good agreement with reviewed observations. The melting at the base of the ice shelf is primarily due to interaction with High Salinity Shelf Water created from the surface sea‐ice formation in winter. The temperature difference between the coldest waters created in the open ocean and the in situ freezing point of ocean water in contact with the deepest part of the AIS drives a melt rate that can exceed 30 m of ice year −1 . The inclusion of frazil dynamics is shown to be important for both melting and marine ice accretion (refreezing). Frazil initially forms in the supercooled water layer adjacent to the base of the ice shelf. The net accretion of marine ice is 5.3 Gt year −1 , comprised of 3.7 Gt year −1 of frazil accretion and 1.6 Gt year −1 of direct basal refreezing.