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Topographic Shelf Waves Control Seasonal Melting Near Antarctic Ice Shelf Grounding Lines
Author(s) -
Sun Sainan,
Hattermann Tore,
Pattyn Frank,
Nicholls Keith W.,
Drews Reinhard,
Berger Sophie
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl083881
Subject(s) - ice shelf , geology , stratification (seeds) , oceanography , lead (geology) , sea ice , cryosphere , geomorphology , seed dormancy , botany , germination , dormancy , biology
The buttressing potential of ice shelves is modulated by changes in subshelf melting, in response to changing ocean conditions. We analyze the temporal variability in subshelf melting using an autonomous phase‐sensitive radio‐echo sounder near the grounding line of the Roi Baudouin Ice Shelf in East Antarctica. When combined with additional oceanographic evidence of seasonal variations in the stratification and the amplification of diurnal tides around the shelf break topography (Gunnerus Bank), the results suggest an intricate mechanism in which topographic waves control the seasonal melt rate variability near the grounding line. This mechanism has not been considered before and has the potential to enhance local melt rates without advecting different water masses. As topographic waves seem to strengthen in a stratified ocean, the freshening of Antarctic surface water, predicted by observations and models, is likely to increase future basal melting in this area.